Toxins and venoms from marine cnidarians and gastropods: diversity and potential drugs targeting the ion channels

2021 ◽  
Vol 01 ◽  
Author(s):  
Sofiene Tlili ◽  
Raoua Ben Brahim ◽  
Jean-Marc Sabatier ◽  
Imed Regaya
Keyword(s):  
Ion Channels ◽  
Marine Invertebrates ◽  
Marine Organisms ◽  
Active Compounds ◽  
Therapeutic Applications ◽  
Potential Link ◽  
The Relationship ◽  
Bibliographic Study

: A diversity of marine invertebrates, such as cnidarians are rich sources of large bio-active molecules. This chemo-diversity of bio-active compounds has a promising potential in several biotechnological and therapeutic applications. On the basis of a comparative bibliographic approach, we intend in this review to present and discuss an overview of: i) the diversity of marine invertebrates as a candidate for bio-active molecules production; ii) the diversity of bio-active compounds and venom derived from these organisms; iii) the relationship between, the diversity of these marine organisms and the structure of the toxins they secrete. In this bibliographic study, a focus is going to be made on protein neurotoxins targeting ion channels. We also discuss the potential link between the bioecological characteristics of cnidarians and the diversity of toxins.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Statistical Analysis of the Relationship Between Antioxidant Activity and the Structure of Flavonoid Compounds

2019 ◽  
Vol 70 (9) ◽  
pp. 3103-3107 ◽  
Author(s):  
Ioana Glevitzky ◽  
Gabriela Alina Dumitrel ◽  
Mirel Glevitzky ◽  
Bianca Pasca ◽  
Pavel Otrisal ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Activities ◽  
Basic Structure ◽  
Oh Groups ◽  
Flavonoid Compounds ◽  
Chi Squared ◽  
Potential Link ◽  
Van Der Waals Surface ◽  
The Relationship ◽  
Phenolic Oh Groups

Using different methods of statistics, this paper aims to highlight the potential link between the antioxidant activity of flavonoids and the corresponding molecular descriptors. By calculating the descriptors (van der Waals surface (A), molar volume (V), partition coefficient (LogP), refractivity (R), polarizability (a), forming heat (Hformation), hydration energy (Ehidr), the dipole moment (mt)), together with antioxidant activities (RSA) calculated or taken from the literature, number of phenolic -OH groups and the presence (2) or absence (1) of C2=C3 double bond) for 29 flavonoid compounds and by intercorrelation between the studied parameters, the link between the number of phenolic groups grafted to the basic structure of flavonoids and their antioxidant activity was confirmed. Simultaneously, by using the chi-squared test and the intercorrelations matrix, a satisfactorily correlation coefficient (r2=0.5678; r=0.7536) between the structure of the flavonoids and their activity was obtained, fact that confirms the correlation of the antioxidant activity with the number of -OH phenolic groups.

scholarly journals Sphingolipids of Asteroidea and Holothuroidea: Structures and Biological Activities

Marine Drugs ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 330
Author(s):  
Timofey V. Malyarenko ◽  
Alla A. Kicha ◽  
Valentin A. Stonik ◽  
Natalia V. Ivanchina
Keyword(s):  
Marine Invertebrates ◽  
Biological Activities ◽  
Complete Information ◽  
Structural Features ◽  
Marine Organisms ◽  
Structural Components ◽  
Chemical Structures ◽  
The Past ◽  
Complex Lipids ◽  
Complex Sphingolipids

Sphingolipids are complex lipids widespread in nature as structural components of biomembranes. Commonly, the sphingolipids of marine organisms differ from those of terrestrial animals and plants. The gangliosides are the most complex sphingolipids characteristic of vertebrates that have been found in only the Echinodermata (echinoderms) phylum of invertebrates. Sphingolipids of the representatives of the Asteroidea and Holothuroidea classes are the most studied among all echinoderms. In this review, we have summarized the data on sphingolipids of these two classes of marine invertebrates over the past two decades. Recently established structures, properties, and peculiarities of biogenesis of ceramides, cerebrosides, and gangliosides from starfishes and holothurians are discussed. The purpose of this review is to provide the most complete information on the chemical structures, structural features, and biological activities of sphingolipids of the Asteroidea and Holothuroidea classes.

scholarly journals Exploring Neural Signal Complexity as a Potential Link between Creative Thinking, Intelligence, and Cognitive Control

2021 ◽  
Vol 9 (4) ◽  
pp. 59
Author(s):  
Yadwinder Kaur ◽  
Selina Weiss ◽  
Changsong Zhou ◽  
Rico Fischer ◽  
Andrea Hildebrandt
Keyword(s):  
Cognitive Control ◽  
Creative Thinking ◽  
Divergent Thinking ◽  
Crystallized Intelligence ◽  
Multi Scale ◽  
Common Basis ◽  
Multiple Neural Networks ◽  
Potential Link ◽  
Signal Complexity ◽  
The Relationship

Functional connectivity studies have demonstrated that creative thinking builds upon an interplay of multiple neural networks involving the cognitive control system. Theoretically, cognitive control has generally been discussed as the common basis underlying the positive relationship between creative thinking and intelligence. However, the literature still lacks a detailed investigation of the association patterns between cognitive control, the factors of creative thinking as measured by divergent thinking (DT) tasks, i.e., fluency and originality, and intelligence, both fluid and crystallized. In the present study, we explored these relationships at the behavioral and the neural level, based on N = 77 young adults. We focused on brain-signal complexity (BSC), parameterized by multi-scale entropy (MSE), as measured during a verbal DT and a cognitive control task. We demonstrated that MSE is a sensitive neural indicator of originality as well as inhibition. Then, we explore the relationships between MSE and factor scores indicating DT and intelligence. In a series of across-scalp analyses, we show that the overall MSE measured during a DT task, as well as MSE measured in cognitive control states, are associated with fluency and originality at specific scalp locations, but not with fluid and crystallized intelligence. The present explorative study broadens our understanding of the relationship between creative thinking, intelligence, and cognitive control from the perspective of BSC and has the potential to inspire future BSC-related theories of creative thinking.

scholarly journals Dendritic osmosensors modulate activity-induced calcium influx in oxytocinergic magnocellular neurons of the mouse PVN

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Wanhui Sheng ◽  
Scott W Harden ◽  
Yalun Tan ◽  
Eric G Krause ◽  
Charles J Frazier
Keyword(s):  
Ion Channels ◽  
Paraventricular Nucleus ◽  
Calcium Influx ◽  
Optical Recording ◽  
Magnocellular Neurons ◽  
Axon Terminals ◽  
Dendritic Membrane ◽  
Oxytocin Release ◽  
The Relationship ◽  
Existing Data

Hypothalamic oxytocinergic magnocellular neurons have a fascinating ability to release peptide from both their axon terminals and from their dendrites. Existing data indicates that the relationship between somatic activity and dendritic release is not constant, but the mechanisms through which this relationship can be modulated are not completely understood. Here we use a combination of electrical and optical recording techniques to quantify activity-induced calcium influx in proximal vs. distal dendrites of oxytocinergic magnocellular neurons located in the paraventricular nucleus of the hypothalamus (OT-MCNs). Results reveal that the dendrites of OT-MCNs are weak conductors of somatic voltage changes, however activity-induced dendritic calcium influx can be robustly regulated by both osmosensitive and non-osmosensitive ion channels located along the dendritic membrane. Overall, this study reveals that dendritic conductivity is a dynamic and endogenously regulated feature of OT-MCNs that is likely to have substantial functional impact on central oxytocin release.

scholarly journals Bioactive Prenyl- and Terpenyl-Quinones/Hydroquinones of Marine Origin †

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 292 ◽  
Author(s):  
Pablo García ◽  
Ángela Hernández ◽  
Arturo San Feliciano ◽  
Mª Castro
Keyword(s):  
Secondary Metabolites ◽  
Marine Organisms ◽  
Chemical Diversity ◽  
Rich Source ◽  
Pharmacological Properties ◽  
Active Compounds ◽  
Marine Origin ◽  
Synthetic Approaches

The sea is a rich source of biological active compounds, among which terpenyl-quinones/hydroquinones constitute a family of secondary metabolites with diverse pharmacological properties. The chemical diversity and bioactivity of those isolated from marine organisms in the last 10 years are summarized in this review. Aspects related to synthetic approaches towards the preparation of improved bioactive analogues from inactive terpenoids are also outlined.

A new look at the meeting clustering effect

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ángel Pardo ◽  
Eddie Santandreu
Keyword(s):  
Stock Returns ◽  
Stock Exchange ◽  
Abnormal Returns ◽  
Relevant Information ◽  
Investor Attention ◽  
Content Type ◽  
Potential Link ◽  
Clustering Effect ◽  
Trading Volumes ◽  
The Relationship

PurposeThe study aims to test the existence of a meeting clustering effect in the Spanish Stock Exchange (SSE).Design/methodology/approachThis paper studies the relationship between the clustering of annual general meetings and stock returns in the SSE. A multivariate analysis is carried out in order to analyse the relationship between monthly returns and the clustering of general meetings in the SSE.FindingsThe authors show that meeting clustering exists and that some months exhibit significant and positive additional returns related to the holding of ordinary or extraordinary general meetings.Research limitations/implicationsThe authors have explored some possible explanations for the meeting clustering effect, such as a potential link with the “Halloween” effect or the presence of higher-than-normal levels of volatility, trading volumes or investor attention. However, none of these can explain the meeting clustering effect that emerges as a new anomaly in the SSE.Practical implicationsThe authors have documented significant and positive abnormal returns in some months that coincide with the holding of general meetings. Therefore, the holding of ordinary and/or extraordinary meetings in some months involves the release of relevant information for investors.Originality/valueThis study complements the financial literature because it is focused on the clustering of meetings and its effect on a stock market whose legal order is based on civil law. This fact allows us to shed new light on meeting clustering and its effect on other types of markets.

scholarly journals The Influence of Socioeconomic Status on Snacking and Weight among Adolescents: A Scoping Review

Nutrients ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 167 ◽  
Author(s):  
Victoria G. Williamson ◽  
Abhaya Dilip ◽  
Jackson R. Dillard ◽  
Jane Morgan-Daniel ◽  
Alexandra M. Lee ◽  
...  
Keyword(s):  
Socioeconomic Status ◽  
Scoping Review ◽  
Eating Behaviors ◽  
Preliminary Evidence ◽  
Primary Objective ◽  
Bibliographic Databases ◽  
Increased Risk ◽  
Potential Link ◽  
Secondary Objective ◽  
The Relationship

Eating behaviors, including unhealthy snacking or excessive snacking leading to excess calorie consumption, may contribute to obesity among adolescents. Socioeconomic status (SES) also significantly influences eating behaviors, and low SES is associated with increased risk for obesity. However, little is known regarding the relationship between snacking behavior and SES among adolescents and how this may contribute to obesity-related outcomes. The primary objective of this scoping review was to review the literature to assess and characterize the relationship between SES and snacking in adolescents. The secondary objective was to assess weight-related outcomes and their relation to snacking habits. Included articles were published between January 2000 and May 2019; written in English, Portuguese, or Spanish; and focused on adolescents (13–17 years). In total, 14 bibliographic databases were searched, and seven studies met the inclusion criteria. Preliminary evidence from the seven included studies suggests a weak but potential link between SES and snacking. Additionally, these dietary patterns seemed to differ by sex and income type of country. Finally, only three of the included studies addressed weight-related outcomes, but the overall available evidence suggests that snacking does not significantly affect weight-related outcomes. Due to the small number of included studies, results should be interpreted with caution.

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