Non-pathological Conditions Research Articles

Metabolic signatures of metabolites of the purine degradation pathway in human plasma using HILIC UHPLC–HRMS

The metabolic disorders in the purine degradation pathway have proven to be closely associated with several human diseases. However, the etiology is not yet fully understood. Profile assay of purine intermediates and uric acid involved in the metabolic pathway can provide additional insight into the nature and severity of related diseases. Purine metabolites are endogenous chemicals with high hydrophilicity, polarity, and similar structures, thus there is a great need for a specific method to quantify them directly in biological fluids with a short running time. Herein, eight purine degradation pathway metabolites, including xanthine, hypoxanthine, guanine, xanthosine, inosine, guanosine, adenosine and uric acid, in human plasma were quantitatively measured using hydrophilic interaction chromatography-tandem high-resolution mass spectrometry (HILIC-HRMS) in a short running time of 10 min. The method was systematically validated for specificity, linearity of the calibration curve, the limit of detection, the limit of quantification, the lower limit of quantification, precision, accuracy, extraction recovery, matrix effect, and stability. The results showed that the method was linear (R2 > 0.99), accurate (the intra- and inter-day recoveries of all analytes ranged from 90.0 % to 110.0 %), and precise (the intra- and inter-day precisions were less than 6.7 % and 8.9 %, respectively) with the lower limits of quantification ranging from 3 to 10,000 ng/mL. The extraction recoveries and matrix effects were repeatable and stable. All the analytes were stable in the autosampler and could be subject to three freeze-thaw cycles. The developed method was ultimately applied to 100 plasma specimens from healthy individuals. The results showed that the concentrations of different purine metabolites varied dramatically in plasma specimens. Diet and body mass index (BMI) were the most significant factors determining purine levels, followed by drinking and sex. Age, smoking and bedtime showed a very weak correlation with purine metabolism. The findings of the present work reveal the characteristics of purine metabolism in human plasma under non-pathological conditions. The results also highlight the factors that can cause changes in purine metabolism, which are useful in developing effective treatment strategies for metabolic disorders of purines, particularly for those caused by lifestyle factors.

Deciphering the role of brainstem glycinergic neurons during startle and prepulse inhibition

Prepulse inhibition (PPI) of the auditory startle response, a key measure of sensorimotor gating, diminishes with age and is impaired in various neurological conditions. While PPI deficits are often associated with cognitive impairments, their reversal is routinely used in experimental systems for antipsychotic drug screening. Yet, the cellular and circuit-level mechanisms of PPI remain unclear, even under non-pathological conditions. We recently showed that brainstem neurons located in the caudal pontine reticular nucleus (PnC) expressing the glycine transporter type 2 (GlyT2±) receive inputs from the central nucleus of the amygdala (CeA) and contribute to PPI but via an uncharted pathway. Here, using tract-tracing, immunohistochemistry and in vitro optogenetic manipulations coupled to field electrophysiological recordings, we reveal the neuroanatomical distribution of GlyT2± PnC neurons and PnC-projecting CeA glutamatergic neurons and we provide mechanistic insights on how these glutamatergic inputs suppress auditory neurotransmission in PnC sections. Additionally, in vivo experiments using GlyT2-Cre mice confirm that optogenetic activation of GlyT2± PnC neurons enhances PPI and is sufficient to induce PPI in young mice, emphasizing their role. However, in older mice, PPI decline is not further influenced by inhibiting GlyT2± neurons. This study highlights the importance of GlyT2± PnC neurons in PPI and underscores their diminished activity in age-related PPI decline.

Amyloid Pathology Impairs Experience-Dependent Inhibitory Synaptic Plasticity.

Alzheimer's disease patients and mouse models exhibit aberrant neuronal activity and altered excitatory-to-inhibitory synaptic ratio. Using multicolor two-photon microscopy, we test how amyloid pathology alters the structural dynamics of excitatory and inhibitory synapses and their adaptation to altered visual experience in vivo in the visual cortex. We show that the baseline dynamics of mature excitatory synapses and their adaptation to visual deprivation are not altered in amyloidosis. Likewise, the baseline dynamics of inhibitory synapses are not affected. In contrast, visual deprivation fails to induce inhibitory synapse loss in amyloidosis, a phenomenon observed in nonpathological conditions. Intriguingly, inhibitory synapse loss associated with visual deprivation in nonpathological mice is accompanied by subtle broadening of spontaneous but not visually evoked calcium transients. However, such broadening does not manifest in the context of amyloidosis. We also show that excitatory and inhibitory synapse loss is locally clustered under the nonpathological state. In contrast, a fraction of synapse loss is not locally clustered in amyloidosis, indicating an impairment in inhibitory synapse adaptation to changes in excitatory synaptic activity.

Activity-dependent ectopic action potentials in regular-spiking neurons of the neocortex.

Action potentials usually travel orthodromically along a neuron's axon, from the axon initial segment (AIS) toward the presynaptic terminals. Under some circumstances action potentials also travel in the opposite direction, antidromically, after being initiated at a distal location. Given their initiation at an atypical site, we refer to these events as "ectopic action potentials." Ectopic action potentials (EAPs) were initially observed in pathological conditions including seizures and nerve injury. Several studies have described regular-spiking (RS) pyramidal neurons firing EAPs in seizure models. Under nonpathological conditions, EAPs were reported in a few populations of neurons, and our group has found that EAPs can be induced in a large proportion of parvalbumin-expressing interneurons in the neocortex. Nevertheless, to our knowledge there have been no prior reports of ectopic firing in the largest population of neurons in the neocortex, pyramidal neurons, under nonpathological conditions. We performed in vitro recordings utilizing the whole-cell patch clamp technique. To elicit EAPs, we triggered orthodromic action potentialswith either long, progressively increasing current steps, or with trains of brief pulses at 30, 60, or 100 Hz delivered in 3 different ways, varying in stimulus and resting period duration. We found that a large proportion (72.7%) of neocortical RS cells from mice can fire EAPs after a specific stimulus in vitro, and that most RS cells (56.1%) are capable of firing EAPs across a broad range of stimulus conditions. Of the 37 RS neurons in which we were able to elicit EAPs, it took an average of 863.8 orthodromic action potentials delivered over the course of an average of ~81.4 s before the first EAP was seen. We observed that some cells responded to specific stimulus frequencies while less selective, suggesting frequency tuning in a subset of the cells. Our findings suggest that pyramidal cells can integrate information over long time-scales before briefly entering a mode of self-generated firing that originates in distal axons. The surprising ubiquity of EAP generation in RS cells raises interesting questions about the potential roles of ectopic spiking in information processing, cortical oscillations, and seizure susceptibility.

Betalains Alleviate Exercise-Induced Oxidative Stress, Inflammation, and Fatigue and Improve Sports Performance: an Update on Recent Advancement.

Beetroot juice is a popular natural food supplement commonly consumed for its health and ergogenic benefits. It contains an abundance of phytochemical compounds, which have been shown to enhance sports endurance and recovery. Among them, nitrate is well-studied and known for improving performance during exercise. On the other hand, betalains, the bioactive pigment, have shown various biological activities including antioxidant, anti-inflammatory, and anti-hypertensive, which may improve exercise performance and post-exercise recovery. Additionally, free radical scavenging activities of betalains could increase nitric oxide availability in the blood, thereby improving blood flow and oxygen supply during strenuous exercise. This review article provides a critical discussion of the non-pathological conditions induced by prolonged or strenuous exercise and betalains' potential in reducing such conditions including muscle damage, inflammation, and fatigue. Additionally, the real-time application of betalains as an ergogenic compound in competitive athletes has been discussed. Finally, future directions and conclusions on the potential of betalains as a natural ergogenic aid in sport endurance are outlined. Betalains in beetroot are the major water-soluble nitrogen-containing pigment possessing high antioxidant, anti-inflammatory, and anti-fatigue activities. Betalain supplementation could alleviate exercise-induced oxidative stress, inflammation, and fatigue in competitive athletes. Betalains have the potential to become a natural ergogenic aid or nutraceutical compound for sports people during exercise and competitive performance.

Ex Vivo Infection of Human Skin Models with Herpes Simplex Virus 1: Accessibility of the Receptor Nectin-1 during Formation or Impairment of Epidermal Barriers Is Restricted by Tight Junctions.

Herpes simplex virus 1 (HSV-1) must overcome epidermal barriers to reach its receptors on keratinocytes and initiate infection in human skin. The cell-adhesion molecule nectin-1, which is expressed in human epidermis, acts as an efficient receptor for HSV-1 but is not within reach of the virus upon exposure of human skin under nonpathological conditions. Atopic dermatitis skin, however, can provide an entry portal for HSV-1 emphasizing the role of impaired barrier functions. Here, we explored how epidermal barriers impact HSV-1 invasion in human epidermis and influence the accessibility of nectin-1 for the virus. Using human epidermal equivalents, we observed a correlation of the number of infected cells with tight-junction formation, suggesting that mature tight junctions prior to formation of the stratum corneum prevent viral access to nectin-1. Consequently, impaired epidermal barriers driven by Th2-inflammatory cytokines interleukin 4 (IL-4) and IL-13 as well as the genetic predisposition of nonlesional atopic dermatitis keratinocytes correlated with enhanced infection supporting the impact of functional tight junctions for preventing infection in human epidermis. Comparable to E-cadherin, nectin-1 was distributed throughout the epidermal layers and localized just underneath the tight-junctions. While nectin-1 was evenly distributed on primary human keratinocytes in culture, the receptor was enriched at lateral surfaces of basal and suprabasal cells during differentiation. Nectin-1 showed no major redistribution in the thickened atopic dermatitis and IL-4/IL-13-treated human epidermis in which HSV-1 can invade. However, nectin-1 localization toward tight junction components changed, suggesting that defective tight-junction barriers make nectin-1 accessible for HSV-1 which enables facilitated viral penetration. IMPORTANCE Herpes simplex virus 1 (HSV-1) is a widely distributed human pathogen which productively infects epithelia. The open question is which barriers of the highly protected epithelia must the virus overcome to reach its receptor nectin-1. Here, we used human epidermal equivalents to understand how physical barrier formation and nectin-1 distribution contribute to successful viral invasion. Inflammation-induced barrier defects led to facilitated viral penetration strengthening the role of functional tight-junctions in hindering viral access to nectin-1 that is localized just underneath tight junctions and distributed throughout all layers. We also found nectin-1 ubiquitously localized in the epidermis of atopic dermatitis and IL-4/IL-13-treated human skin implying that impaired tight-junctions in combination with a defective cornified layer allow the accessibility of nectin-1 to HSV-1. Our results support that successful invasion of HSV-1 in human skin relies on defective epidermal barriers, which not only include a dysfunctional cornified layer but also depend on impaired tight junctions.

Deep characterization of human γδ T cell subsets defines shared and lineage-specific traits.

Under non-pathological conditions, human γδ T cells represent a small fraction of CD3+ T cells in peripheral blood (1-10%). They constitute a unique subset of T lymphocytes that recognize stress ligands or non-peptide antigens through MHC-independent presentation. Major human γδ T cell subsets, Vδ1 and Vδ2, expand in response to microbial infection or malignancy, but possess distinct tissue localization, antigen recognition, and effector responses. We hypothesized that differences at the gene, phenotypic, and functional level would provide evidence that γδ T cell subpopulations belong to distinct lineages. Comparisons between each subset and the identification of the molecular determinants that underpin their differences has been hampered by experimental challenges in obtaining sufficient numbers of purified cells. By utilizing a stringent FACS-based isolation method, we compared highly purified human Vδ1 and Vδ2 cells in terms of phenotype, gene expression profile, and functional responses. We found distinct genetic and phenotypic signatures that define functional differences in γδ T cell populations. Differences in TCR components, repertoire, and responses to calcium-dependent pathways suggest that Vδ1 and Vδ2 T cells are different lineages. These findings will facilitate further investigation into the ligand specificity and unique role of Vδ1 and Vδ2 cells in early immune responses.

Overview of Microorganism Patterns Causing Pathological Fluor Albus at Dr. Mohammad Hoesin General Hospital, Palembang, Indonesia

Background: Fluor albus, also known as leucorrhoea, vaginal discharge, or leukorrhea, is the name given to fluids that are secreted from the genitals that are not blood. Pathological fluor albus can be caused by an infection in the lower genitalia or in areas that are more proximal. This study aimed to determine the pattern of microorganisms that cause pathological fluor albus at Dr. Mohammad Hoesin General Hospital, Palembang, Indonesia.
 Methods: This study was a descriptive observational study and used primary data from a direct examination of research subjects at the obstetrics and gynecology polyclinic of Dr. Mohammad Hoesin General Hospital, Palembang, Indonesia. A total of 63 research subjects participated in this study. Analysis of microorganism patterns was carried out univariately using SPSS software.
 Results: The majority of microorganisms that cause pathological fluor albus are Gardnerella vaginalis. Meanwhile, in non-pathological conditions of fluor albus, the majority of causative microorganisms are E. coli. 
 Conclusion: Gardnerella vaginalis is the most common causative microorganism of pathological fluor albus disorders at Dr. Mohammad Hoesin General Hospital, Palembang, Indonesia.

Excitation-inhibition imbalance disrupts visual familiarity in amyloid and non-pathology conditions

Neuronal hyperactivity induces memory deficits in Alzheimer's disease. However, how hyperactivity disrupts memory is unclear. Using invivo synaptic imaging in the mouse visual cortex, we show that structural excitatory-inhibitory synapse imbalance in the apical dendrites favors hyperactivity in early amyloidosis. Consistent with this, natural images elicit neuronal hyperactivity in these mice. Compensatory changes that maintain activity homeostasis disrupt functional connectivity and increase population sparseness such that a small fraction of neurons dominates population activity. These properties reduce the selectivity of neural response to natural images and render visual recognition memory vulnerable to interference. Deprivation of non-specific visual experiences improves the neural representation and behavioral expression of visual familiarity. In contrast, in non-pathological conditions, deprivation of non-specific visual experiences induces disinhibition, increases excitability, and disrupts visual familiarity. We show that disrupted familiarity occurs when the fraction of high-responsive neurons and the persistence of neural representation of a memory-associated stimulus are not constrained.

Protein kinase R dependent phosphorylation of α-synuclein regulates its membrane binding and aggregation.

Aggregated α-synuclein (α-syn) accumulates in the neuronal Lewy body (LB) inclusions in Parkinson's disease (PD) and LB dementia. Yet, under nonpathological conditions, monomeric α-syn is hypothesized to exist in an equilibrium between disordered cytosolic- and partially α-helical lipid-bound states: a feature presumably important in synaptic vesicle release machinery. The exact underlying role of α-syn in these processes, and the mechanisms regulating membrane-binding of α-syn remains poorly understood. Herein we demonstrate that Protein kinase R (PKR) can phosphorylate α-syn at several Ser/Thr residues located in the membrane-binding region that is essential for α-syn's vesicle-interactions. α-Syn phosphorylated by PKR or α-syn isolated from PKR overexpressing cells, exhibit decreased binding to lipid membranes. Phosphorylation of Thr64 and Thr72 appears as the major contributor to this effect, as the phosphomimetic Thr64Glu/Thr72Glu-α-syn mutant displays reduced overall attachment to brain vesicles due to a decrease in vesicle-affinity of the last two thirds of α-syn's membrane binding region. This allows enhancement of the "double-anchor" vesicle-binding mechanism that tethers two vesicles and thus promote the clustering of presynaptic vesicles in vitro. Furthermore, phosphomimetic Thr64Glu/Thr72Glu-α-syn inhibits α-syn oligomerization and completely abolishes nucleation, elongation, and seeding of α-syn fibrillation in vitro and in cells, and prevents trans-synaptic spreading of aggregated α-syn pathology in organotypic hippocampal slice cultures. Overall, our findings demonstrate that normal and abnormal functions of α-syn, like membrane-binding, synaptic vesicle clustering and aggregation can be regulated by phosphorylation, e.g., via PKR. Mechanisms that could potentially be modulated for the benefit of patients suffering from α-syn aggregate-related diseases.

Hallux Valgus Angular Measurements using WBCT Semiautomatic and Manual Assessments

Category: Bunion; Lesser Toes; Midfoot/Forefoot Introduction/Purpose: Radiographic measurements are an essential tool to determine the appropriate surgical treatment and outcome for Hallux Valgus (HV). WBCT already demonstrates significant advances that include the ability to perform traditional measurements for HV in the 3D setting reliably, as well as a more complete and accurate evaluation of the deformity. In addition, new software with an advanced semi-automated segmentation system obtains semi-automatic 3D measurements of WBCT scan data sets, minimizing the errors in reading angular measurements. The objective was (1) to assess the reliability of WBCT computer-assisted semi-automatic imaging measurements in HV, (2) to compare semi-automatic with manual measurements in the setting of an HV, and (3) to compare semi-automatic measurements between HV and control group. Methods: In this retrospective IRB (ID# 201904825) approved study, we assessed patients with hallux valgus deformity. The sample size calculation was based on the hallux valgus angle (HVA). Thus, to obtain the 0.8 power, including 26 feet with HV in this study, was necessary. Our control group consisted of 19 feet from 19 patients without HV. Raw multiplanar data was evaluated using software CubeVue. In the axial plane, hallux valgus angle (HVA), intermetatarsal angle (IMA), and interphalangeal angle (IPA) were measured. The semiautomatic 3D measurements were performed using the Bonelogic Software. Inter-rater reliabilities were performed using ICC. Agreement between methods was tested using the Bland-Altman plots. The difference between Pathologic and Control cases using semi-automatic measurements was assessed with the Wilcoxon signed-rank test. Alpha risk was set to 5% (α = 0.05). P<= 0.05 was considered significant. Results: Intraobserver and Interobserver agreement and consistency for Manual and Semi-automatic WBCT measurements assessed by ICC demonstrated excellent reliability in both cases. However, when comparing Manual and Semi-automatic measurements for HVA, IMA, and IPA, Semi-automatic measurements showed the highest values. Agreement between manual (M) and semi-automatic (SA) methods was tested for HVA, IMA and IPA using the Bland-Altman plots. The results indicated a high correlation between the parameters calculated from the manual and semi-automatic measurements, and a strong agreement between the readers and the software. Comparison between pathological group with HV and control (standard) group without HV using semi-automatic measurements was capable of differentiating pathological (HV) from non-pathological conditions for the HVA and IMA angles (p < 0,05). Conclusion: Semi-automatic measurements are reproducible and comparable to measurements performed manually. The software differentiated pathological from non-pathological conditions when subjected to semi-automatic measurements. The development of advanced semi-automatic segmentation software with minimal user intervention is essential for the establishment of big data and can be integrated into clinical practice, facilitating decision-making.

The Use of Advanced Semi-Automated Bone Segmentation in Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Weight-Bearing Computed Tomography (WBCT) measurements represent a reliable tool for radiographic analysis of the first ray, including multiplanar assessment in the axial, sagittal, and coronal planes. WBCT can allow for more reliable studies of pathologies, such as Hallux Rigidus (HR), which permits several anatomical points to be evaluated for a correct clinical-radiographic diagnosis. In addition, new software with an advanced semi-automated segmentation system obtains semi-automatic 3D measurements of WBCT scan data sets, minimizing the errors in reading angular measurements. The study`s objective was (1) to assess the reliability of WBCT computer-assisted semi-automatic imaging measurements in HR, (2) to compare semi-automatic to manual measurements in the setting of HR, and (3) to compare semi-automatic measurements between a pathologic (HR) group and a control standard group. Methods: This was a retrospective, IRB approved study of patients with Hallux Rigidus deformity. The sample size calculation was based on the Metatarsus Primus Elevatus (MPE). A control group consisting of 20 feet without HR and a pathologic group consisting of 20 feet with HR was necessary for this study. All WBCT manual and semiautomatic 3D measurements were performed using the following parameters: (1) first Metatarsal-Proximal Phalanx Angle (1stMPP) (sagittal plane), (2) Hallux Valgus Angle (HVA), (3) first to second Intermetatarsal Angle (IMA), (4) Hallux Interphalangeal Angle (IPA), (5) first Metatarsal Lengths (1stML), (6) second Metatarsal Length (2ndML), (7) first Metatarsal Declination Angle (1stMD), (8) second Metatarsal Declination Angles (2ndMD), and (9) MPE. The semiautomatic 3D measurements were performed using the Bonelogic Software. The differences between pathologic and control cases were assessed with a Wilcoxon test and P<= 0.05 was considered significant. Results: Interobserver and intraobserver agreement and consistency for manual versus semi-automatic WBCT measurements assessed by ICC demonstrated excellent reliability. Manual and semi-automatic measurements were performed in individuals with HR. According to the Pearson's coefficient, there was a strong positive linear correlation between both methods for the following parameters evaluated: HVA, (ρ = 0.96); IMA, (ρ = 0.86); IPA, (ρ = 0.89); 1stML, (ρ = 0.96); 2ndML, (ρ = 0.91); 1stMD, (ρ = 0.86); 2ndMD, (ρ = 0.95) and, MPE, (ρ = 0.87). Agreement between the manual and semi-automatic methods was tested using a Bland- Altman plot and expressed excellent agreement between the methods. Comparison between the pathological group with HR and the control (standard) group allowed for the differentiating of the pathological (HR) from the non-pathological conditions for MPE (p < 0.05). Conclusion: Semiautomatic measurements are reproducible and comparable to measurements performed manually, showing excellent interobserver and intraobserver agreement and consistency. The software used differentiated pathological from non- pathological conditions only when submitted to semi-automatic MPE measurements. The development of advanced semi-automatic segmentation software with minimal user intervention is an essential step toward the establishment of big data and can be integrated into clinical practice, facilitating decision making.

Dihydroartemisinin regulates immune cell heterogeneity by triggering a cascade reaction of CDK and MAPK phosphorylation

Artemisinin (ART) and dihydroartemisinin (DHA), apart from their profound anti-malaria effect, can also beneficially modulate the host immune system; however, the underlying molecular mechanisms remain unclear. Here, we report that DHA selectively induced T-cell activation, with an increased proportion of Ki67+CD4+ T cells, CD25+CD4+ T cells, interferon (IFN)-γ-producing CD8+ T cells, Brdu+ CD8+ T cells and neutrophils, which was found to enhance cellular immunity to experimental malaria and overcome immunosuppression in mice. We further revealed that DHA upregulated the expression of cell proliferation-associated proteins by promoting the phosphorylation of mitogen-activated protein kinase (MAPK), cyclin-dependent kinases (CDKs), and activator protein 1 in the spleen. This study is the first to provide robust evidence that DHA selectively induced the expansion of subsets of splenic T cells through phosphorylated CDKs and MAPK to enhance cellular immune responses under non-pathological or pathological conditions. The data significantly deepened our knowledge in the mechanism underlying DHA-mediated immunomodulation.

Abstract 831: Discovery of a novel soluble Neuropilin-2 isoform with antiangiogenic and antitumorigenic activity

Abstract Upregulation of the non-tyrosine kinase receptor neuropilin-2 (NRP2) is described for several tumor entities and correlates with disease progression. Two membrane-anchored isoforms are transcribed from the NRP2 gene that only differ in their terminal exons to encode transmembrane stretches and short cytoplasmic tails, respectively. While NRP2a was shown to support tumor cell proliferation, NRP2b facilitates tumor cell migration, resulting in enhanced metastatic spreading. A third, soluble NRP2 isoform encoding only aminoterminal protein domains exists as dimeric protein and functions in sequestration of the VEGF-C ligand. By using a next-generation sequencing approach to enrich for NRP2 terminal exons, we identified NRP2-Mo83, a novel NRP2 isoform, from a high expressing tumor cell line, and verified secreted NRP2-Mo83 protein by mass spectrometry in cell supernatants. Preliminary mass spectrometric data give an indication of the presence of soluble NRP2-Mo83 protein in human serum samples.NRP2-Mo83 mRNA is expressed at variable quantities in vitro in a panel of bladder carcinoma cell lines, but is downregulated in a small cohort of macrodissected urothelial carcinoma samples. Transcript abundances of a NRP2 transcript classified as non-coding with high sequence similarity to the NRP2-Mo83 3’ terminus confirm the observed downregulation in the TCGA bladder carcinoma cohort.Preliminary data indicate that recombinant NRP2-Mo83 protein exerts a dose-dependent inhibitory effect on tumor cell growth in vitro in all tested bladder carcinoma cell lines in the presence of serum. However, a fraction of cell lines does not respond to NRP2-Mo83 under serum-starved conditions. Proliferation of human endothelial cells (HUVEC) is inhibited in a dose-dependent manner by recombinant NRP2-Mo83 protein in vitro. In vivo, NRP2-Mo83 reveals an anti-angiogenic effect on the chicken chorioallantoic membrane.Recombinant NRP2-Mo83 is secreted by HEK293 cells. Enrichment of endogenous and purification of recombinant NRP2-Mo83 protein is achieved by exploiting its capacity to bind heparin. In contrast to the described s9NRP2 isoform, NRP2-Mo83 is largely monomeric in solution, as verified by size exclusion chromatography. We identified N and O glycosylation as well as the capacity for polysialation as posttranslational modifications of recombinant NRP2-Mo83 protein, similar to membrane anchored NRP2 isoforms. NanoDSF experiments indicate that calcium ions stabilize NRP2-Mo83. We present NRP2-Mo83 as a novel NRP2 splice isoform, validated its expression at the mRNA and protein level. NRP2-Mo83 appears down-regulated during bladder tumorigenesis, congruent with its function in bladder tumor growth inhibition and its anti-angiogenic properties in vitro and in vivo. The identification of NRP2-Mo83 in human serum may suggest a suppressive function even under non-pathological conditions. Citation Format: Thomas Mayr, Paul L. Dix, Sayed-Mohammad Hasheminasab, Chuanpit Hampel, Marc Sylvester, Niels Schneberger, Sarah Foerster, Gregor Hagelueken, Samikshan Dutta, Glen Kristiansen, Regine Schneider-Stock, Kaustubh Datta, Michael H. Muders. Discovery of a novel soluble Neuropilin-2 isoform with antiangiogenic and antitumorigenic activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 831.

Hydroxytyrosol Alleviated Hypoxia-Mediated PC12 Cell Damage through Activating PI3K/AKT/mTOR-HIF-1α Signaling.

Background Hypoxia exerts pressure on cells and organisms, and this pressure can occur under both pathological and nonpathological conditions. There are many reports confirmed that hydroxytyrosol has good in vitro antioxidant activity, while the research about hydroxytyrosol on hypoxia-mediated cell damage is still unclear. Purpose The aim of this study was to investigate the effect and mechanism of hydroxytyrosol on hypoxia-mediated cell damage. Methods We studied the effects of hydroxytyrosol on the content of reactive oxygen species, the change of antioxidant enzymes activity of SOD, CAT, and GSH-Px and the content of oxidation products MDA and GSH, and the changes of cell membrane potential and effect on PI3K/AKT/mTOR-HIF-1α signaling pathway under hypoxia-mediated PC12 cell. Results PC12 cell treated with hydroxytyrosol abated the cell apoptosis and alleviated the oxidative stress through scavenging of reactive oxygen species, improving the enzyme activity and changing the content of oxidation products and alleviating mitochondria damage. Western blotting confirmed that the mechanism maybe related to the PI3K/AKT/mTOR-HIF-1α signaling pathway. The inhibition experiment confirmed that hydroxytyrosol takes part in the expression of protein PI3K and p-mTOR. Conclusion Hydroxytyrosol reduced the oxidative stress and resisted the inhibition of PI3K/AKT/mTOR-HIF-1α signaling pathway caused by hypoxia, improved cell apoptosis, and ameliorated the antihypoxia ability of PC12 cells under hypoxia.

Selfless Memories

Many authors claim that being conscious constitutively involves being self-conscious, or conscious of oneself. This claim appears to be threatened by reports of ‘selfless’ episodes, or conscious episodes lacking self-consciousness, recently described in a number of pathological and nonpathological conditions. However, the credibility of these reports has in turn been challenged on the following grounds: remembering and reporting a past conscious episode as an episode that one went through is only possible if one was conscious of oneself while undergoing it. Call this the Memory Challenge. This paper argues that the Memory Challenge fails to undermine the credibility to reports of selfless episodes, because it rests on problematic assumptions about episodic memory. The paper further argues that we should distinguish between several kinds of self-representation that may be involved in the process of episodic remembering, and that once we do so, it is no longer mysterious how one could accurately remember and report a selfless episode as an episode that one went through. Thus, we should take reports of this kind seriously, and view them as credible counter-examples to the claim that consciousness constitutively involves self-consciousness.

Hiperintensidad en secuencia FLAIR del LCR en el espacio subaracnoideo: diagnósticos diferenciales

The fluid-attenuated inversion recovery (FLAIR) sequence forms part of the vast majority of current diagnostic protocols for brain MRI. This sequence enables the suppression of the signal from cerebrospinal fluid, facilitating the detection of disease involving the subarachnoid space. The causes of hyperintensity in the arachnoid space in this sequence can be divided into two main categories: hyperintensity due to disease and hyperintensity due to artifacts. Hyperintensity due to tumors, inflammation, vascular disease, or hypercellularity of the cerebrospinal fluid or hematic contents is well known. However, numerous other non-pathological conditions, mainly due to artifacts, that are also associated with this finding are a potential source of diagnostic errors.

Comparison between Weightbearing-CT semiautomatic and manual measurements in Hallux Valgus

BackgroundRadiographic measurements are an essential tool to determine the appropriate surgical treatment and outcome for Hallux Valgus (HV). HV deformity is best evaluated by weight-bearing computed tomography (WBCT).The objective was (1) to assess the reliability of WBCT computer-assisted semi-automatic imaging measurements in HV, (2) to compare semi-automatic with manual measurements in the setting of an HV, and (3) to compare semi-automatic measurements between HV and control group. MethodsIn this retrospective IRB (ID# 201904825) approved study, we assessed patients with hallux valgus deformity. The sample size calculation was based on the hallux valgus angle (HVA). Thus to obtain the 0.8 power, including 26 feet with HV in this study, was necessary. Our control group consisted of 19 feet from 19 patients without HV. Raw multiplanar data was evaluated using software CubeVue®. In the axial plane, hallux valgus angle (HVA), intermetatarsal angle (IMA), and interphalangeal angle (IPA) were measured. The semiautomatic 3D measurements were performed using the Bonelogic®Software. Inter-rater reliabilities were performed using ICC. Agreement between methods was tested using the Bland-Altman plots. The difference between Patologic and Control cases using semi-automatic measurements was assessed with the Wilcoxon signed-rank test. Alpha risk was set to 5% (α = 0.05). P ≤ 0.05 were considered significant. ResultsReliabilities utilizing ICC were over 0.80 for WBCT manual measurements and WBCT semi-automatic readings. Inter and intraobserver agreement for Manual and Semi-automatic WBCT measurements demonstrated excellent reliability. ConclusionsSemi-automatic measurements are reproducible and comparable to measurements performed manually. The software differentiated pathological from non-pathological conditions when subjected to semi-automatic measurements. The development of advanced semi-automatic segmentation software with minimal user intervention is essential for the establishment of big data and can be integrated into clinical practice, facilitating decision-making.

Cortical complexity estimation using fractal dimension: A systematic review of the literature on clinical and nonclinical samples.

Fractal geometry has recently been proposed as a useful tool for characterizing the complexity of the brain cortex, which is likely to derive from the recurrence of sulci–gyri convolution patterns. The index used to describe the cortical complexity is called fractal dimensional (FD) and was employed by different research exploring the neurobiological correlates of distinct pathological and nonpathological conditions. This review aims to describe the literature on the application of this index, summarize the heterogeneities between studies and inform future research on this topic. Sixty‐two studies were included in the systematic review. The main research lines concern neurodevelopment, aging and the neurobiology of specific psychiatric and neurological disorders. Overall, the included papers indicate that cortical complexity is likely to reduce during aging and in various pathological processes affecting the brain. Nevertheless, the high heterogeneity between studies strongly prevents the possibility of drawing conclusions. Further research considering this index besides other morphological values is needed to better clarify the role of FD in characterizing the cortical structure.

Impact of blunting astrocyte activity on hippocampal synaptic plasticity in a mouse model of early Alzheimer's disease based on amyloid-β peptide exposure.

Amyloid-β peptides (Aβ) accumulate in the brain since early Alzheimer's disease (AD) and dysregulate hippocampal synaptic plasticity, the neurophysiological basis of memory. Although the relationship between long-term potentiation (LTP) and memory processes is well established, there is also evidence that long-term depression (LTD) may be crucial for learning and memory. Alterations in synaptic plasticity, namely in LTP, can be due to communication failures between astrocytes and neurons; however, little is known about astrocytes' ability to control hippocampal LTD, particularly in AD-like conditions. We now aimed to test the involvement of astrocytes in changes of hippocampal LTP and LTD triggered by Aβ1-42 , taking advantage of L-α-aminoadipate (L-AA), a gliotoxin that blunts astrocytic function. The effects of Aβ1-42 exposure were tested in two different experimental paradigms: ex vivo (hippocampal slices superfusion) and in vivo (intracerebroventricular injection), which were previously validated to impair memory and hippocampal synaptic plasticity, two features of early AD. Blunting astrocytic function with L-AA reduced LTP and LTD amplitude in hippocampal slices from control mice, but the effect on LTD was less evident, suggesting that astrocytes have a greater influence on LTP than on LTD under non-pathological conditions. However, under AD conditions, blunting astrocytes did not consistently alter the reduction of LTP magnitude, but reverted the LTD-to-LTP shift caused by both ex vivo and in vivo Aβ1-42 exposure. This shows that astrocytes were responsible for the hippocampal LTD-to-LTP shift observed in early AD conditions, reinforcing the interest of strategies targeting astrocytes to restore memory and synaptic plasticity deficits present in early AD.