The metamorphosis of amphibian myocardium: moving to the heart of the matter.

Amphibians are a classical object for physiological studies, and they are of great value for developmental studies owing to their transition from an aquatic larval form to an adult form with a terrestrial lifestyle. Axolotls (Ambystoma mexicanum) are of special interest for such studies because of their neoteny and facultative pedomorphosis, as in these animals, metamorphosis can be induced and fully controlled in laboratory conditions. It has been suggested that their metamorphosis, associated with gross anatomical changes in the heart, also involves physiological and electrical remodeling of the myocardium.

Suprastin (Chloropyramine) Causes Proarrhythmic Deterioration of Excitation Conduction, Depolarization and Potentiates Adrenergic Automaticity in the Pulmonary Veins Myocardium.

A number of pharmacological drugs have side effects that contribute to the occurrence of atrial fibrillation, the most common type of cardiac rhythm disorders. The clinical use of antihistamines is widespread; however, information regarding their anti- and/or proarrhythmic effects is contradictory. In this work, we studied the effects and mechanisms of the potential proarrhythmic action of the first-generation antihistamine chloropyramine (Suprastin) in the atrial myocardium and pulmonary vein (PV) myocardial tissue.

3-Methyl-phenanthrene (3-MP) disrupts the electrical and contractile activity of the heart of the polar fish, navaga cod (Eleginus nawaga).

Alkylated polycyclic aromatic hydrocarbons are abundant in crude oil and are enriched during petroleum refinement but knowledge of their cardiotoxicity remains limited. Polycyclic aromatic hydrocarbons (PAHs) are considered the main hazardous components in crude oil and the tricyclic PAH phenanthrene has been singled out for its direct effects on cardiac tissue in mammals and fish. Here we test the impact of the monomethylated phenanthrene, 3-methylphenanthrene (3-MP), on the contractile and electrical function of the atrium and ventricle of a polar fish, the navaga cod (Eleginus nawaga).

Simulating institutional heterogeneity in sustainability science.

Sustainability outcomes are influenced by the laws and configurations of natural and engineered systems as well as activities in socio-economic systems. An important subset of human activity is the creation and implementation of institutions, formal and informal rules shaping a wide range of human behavior. Understanding these rules and codifying them in computational models can provide important missing insights into why systems function the way they do (static) as well as the pace and structure of transitions required to improve sustainability (dynamic).

Distribution of economic damages due to climate-driven sea-level rise across European regions and sectors.

Economic costs of climate change are conventionally assessed at the aggregated global and national levels, while adaptation is local. When present, regionalised assessments are confined to direct damages, hindered by both data and models' limitations. This article goes beyond the aggregated analysis to explore direct and indirect economic consequences of sea level rise (SLR) at regional and sectoral levels in Europe.

Characterization of hERG K channel inhibition by the new class III antiarrhythmic drug cavutilide.

Cavutilide (niferidil, refralon) is a new class III antiarrhythmic drug which effectively terminates persistent atrial fibrillation (AF; 84.6% of patients, mean AF duration 3 months) and demonstrates low risk of torsade de pointes (1.7%).

[Features of the course of COVID-19 in patients with type 2 diabetes mellitus].

Aim: To identify the features of the course of COVID-19 in patients with type 2 diabetes mellitus (T2DM), depending on the intake of hypoglycemic therapy at the prehospital stage, in conjunction with the functional state of the kidneys.

Materials And Methods: A retrospective analysis of 291 case histories of patients with COVID-19 and T2DM hospitalized in the infection department of Semashko Regional Clinical Hospital from January to December 2021, including the main clinical and laboratory parameters. Results.

Economic implications of autonomous adaptation of firms and households in a resource-rich coastal city.

Climate change intensifies the likelihood of extreme flood events worldwide, amplifying the potential for compound flooding. This evolving scenario represents an escalating risk, emphasizing the urgent need for comprehensive climate change adaptation strategies across society. Vital to effective response are models that evaluate damages, costs, and benefits of adaptation strategies, encompassing non-linearities and feedback between anthropogenic and natural systems.

Global Air Pollutant Phenanthrene and Arrhythmic Outcomes in a Mouse Model.

Background: The three-ringed polycyclic aromatic hydrocarbon (PAH) phenanthrene (Phe) has been implicated in the cardiotoxicity of petroleum-based pollution in aquatic systems, where it disrupts the contractile and electrical function of the fish heart. Phe is also found adsorbed to particulate matter and in the gas phase of air pollution, but to date, no studies have investigated the impact of Phe on mammalian cardiac function.

Objectives: Our objectives were to determine the arrhythmogenic potential of acute Phe exposure on mammalian cardiac function and define the underlying mechanisms to provide insight into the toxicity risk to humans.

Uncertainty in boundedly rational household adaptation to environmental shocks.

Despite the growing calls to integrate realistic human behavior in sustainability science models, the representative rational agent prevails. This is especially problematic for climate change adaptation that relies on actions at various scales: from governments to individuals. Empirical evidence on individual adaptation to climate-induced hazards reveals diverse behavioral and social factors affecting economic considerations.

A Rapid and Simple Procedure for the Isolation of Embryonic Cells from Fish Eggs.

Fertilized teleost fish eggs are a complex formation, in which dividing cells are located in a small point in the entire volume of eggs. Isolating embryonic cells can be considered a necessary step in the research of developmental peculiarities of fish cells at the earliest stages of embryogenesis before embryo formation. The main advantages of the offered protocol are rapid isolation, no enzymes, and overall low cost compared to other protocols.

Effects of Non-Opiate Analogue of Leu-Enkephalin on the Ion Currents, Number of Nucleoli, and p53 Expression in Isolated Cardiomyocytes of Albino Rats.

Acute exposure of isolated ventricular cardiomyocytes to non-opiate analogue of leu-enkephalin (NALE peptide: Phe-D-Ala-Gly-Phe-Leu-Arg) in a concentration of 100 μg/liter and 6-h incubation in NALE solution did not significantly change ATP-dependent K current, L-type Ca current, p53 protein expression, and number of nucleoli in the cardiomyocyte nuclei. Incubation of cardiomyocytes with NALE (100 μg/liter) in combination with NOP receptor blocker J-113397 (1 mg/liter) was followed by an increase in Ca L-type current and the number of p53 cells. The exposure of cardiomyocytes to NALE in a concentration 1000 μg/liter induced similar changes in the studied parameters (increase in Ca L-type current and number of p53 cardiomyocytes); an increase in the mean number of nucleoli was also observed.

Tricyclic hydrocarbon fluorene attenuates ventricular ionic currents and pressure development in the navaga cod.

The release of polycyclic aromatic hydrocarbons (PAHs) into the environment due to oil and diesel fuel spills is a serious threat to Arctic fish populations. PAHs produce multiple toxic effects in fish, but disturbance of electrical and contractile activity of the heart seems to be the most negative effect. Our study focused on the effects of fluorene, a tricyclic PAH resembling the well-investigated tricyclic phenanthrene, on major ionic currents and action potential (AP) waveform in isolated ventricular myocytes and on contractile activity in isolated whole hearts of polar navaga cod (Eleginus nawaga).

Sodium current preserves electrical excitability in the heart of hibernating ground squirrel (Citellus undulatus).

Hibernating mammals are capable of maintaining normal cardiac function at low temperatures. Excitability of cardiac myocytes crucially depends on the fast sodium current (I), which is decreased in hypothermia due to both depolarization of resting membrane potential and direct negative effect of low temperature. Therefore, I in hibernating mammals should have specific features allowing to maintain excitability of myocardium at low temperatures.

The Dependence of the Electrophysiological Effects of Class III Antiarrhythmic Drug Refralon on the Frequency of Myocardium Activation.

We studied the frequency dependence of the effects of the novel Russian class III antiarrhythmic drug refralon on the duration of action potentials (AP) in rabbit ventricular myocardium. The absence of an inverse frequency dependence of AP prolongation was demonstrated: the effects of refralon at stimulation frequency of 1 Hz were stronger than at 0.1 Hz.

Uncertainty in individual risk judgments associates with vulnerability and curtailed climate adaptation.

Risk assessments are key for the effective management of potential environmental threats. Across probabilistic phenomena, climate change is an exemplar of paramount uncertainties. These uncertainties have been embraced in supporting governments' decisions; yet receive scarce attention when studying individual behavior.

α1-adrenergic receptors accompanied by GATA4 expression are related to proarrhythmic conduction and automaticity in rat interatrial septum.

The development of interatrial septum (IAS) is a complicated process, which continues during postnatal life. The hypertrophic signals in developing heart are mediated among others by α-adrenergic pathways. These facts suggest the presence of specific electrophysiological features in developing IAS.

Modulation of nuclear and cytoplasmic mRNA fluctuations by time-dependent stimuli: Analytical distributions.

Temporal variation of environmental stimuli leads to changes in gene expression. Since the latter is noisy and since many reaction events occur between the birth and death of an mRNA molecule, it is of interest to understand how a stimulus affects the transcript numbers measured at various sub-cellular locations. Here, we construct a stochastic model describing the dynamics of signal-dependent gene expression and its propagation downstream of transcription.

The role of activation of two different sGC binding sites by NO-dependent and NO-independent mechanisms in the regulation of SACs in rat ventricular cardiomyocytes.

The mechanoelectrical feedback (MEF) mechanism in the heart that plays a significant role in the occurrence of arrhythmias, involves cation flux through cation nonselective stretch-activated channels (SACs). It is well known that nitric oxide (NO) can act as a regulator of MEF. Here we addressed the possibility of SAC's regulation along NO-dependent and NO-independent pathways, as well as the possibility of S-nitrosylation of SACs.

Ionic currents underlying different patterns of electrical activity in working cardiac myocytes of mammals and non-mammalian vertebrates.

The orderly contraction of the vertebrate heart is determined by generation and propagation of cardiac action potentials (APs). APs are generated by the integrated activity of time- and voltage-dependent ionic channels which carry inward Na and Ca currents, and outward K currents. This review compares atrial and ventricular APs and underlying ion currents between different taxa of vertebrates.

One and done? Exploring linkages between households' intended adaptations to climate-induced floods.

As climate change increases the probability and severity of natural hazards, the need for coordinated adaptation at all levels of society intensifies. Governmental-level adaptation measures are essential, but insufficient in the face of growing risks, necessitating complementary action from households. Apprehending the drivers of household adaptation is critical if governments are to stimulate protective behavior effectively.

Contextualizing cross national patterns in household climate change adaptation.

Understanding social and behavioral drivers and constraints of household adaptation is essential to effectively address increasing climate-induced risks. Factors shaping household adaptation are commonly treated as universal; despite an emerging understanding that adaptations are shaped by social, institutional, and cultural contexts. Using original surveys in the United States, China, Indonesia, and the Netherlands (N=3,789) - we explore variations in factors shaping households' adaptations to flooding, the costliest hazard worldwide.

The role of M3 receptors in regulation of electrical activity deteriorates in the rat heart during ageing.

Ageing is a complex process which affects all systems of the organism and therefore changes the environment where the heart is working. In this study we demonstrate the ageing-related changes in the mechanisms of parasympathetic regulation of mammalian heart. Electrophysiological effects produced by selective activation of M3-cholinoreceptors were compared in isolated cardiac preparations from young adult (4 months), adult (1 year) and ageing (2 years) rats using sharp glass microelectrode technique.

Micro-RNA 133a-3p induces repolarization abnormalities in atrial myocardium and modulates ventricular electrophysiology affecting I and Ito currents.

Mir-133a-3p is the most abundant myocardial microRNA. The impact of mir-133a-3p on cardiac electrophysiology is poorly explored. In this study, we investigated the effects of mir-133a-3p on the main ionic currents critical for action potential (AP) generation and electrical activity of the heart.