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Topic Review
Mechanisms behind the Guar Drought Tolerance
Guar is an unpretentious plant and grows on both sandy and well-drained clay soils. Guar is self-pollinating with a negligible level of cross-pollination. The plants considerably vary in height (from 50 cm to 1.5 m). The stem is sturdy, becoming woody by the plant maturation. The main root is thick and tapering in its distal parts, deeply penetrating into the soil. Due to this, guar can perfectly sustain short-term drought. 
  • 363
  • 15 Mar 2024
Topic Review
Oxidative Stress and Neuroinflammation in Diabetic Retinopathy
Diabetic retinopathy (DR) is a neurodegenerative and vascular pathology that is considered one of the leading causes of blindness worldwide, resulting from complications of advanced diabetes mellitus (DM). Therapies consist of protocols aiming to alleviate the existing clinical signs associated with microvascular alterations limited to the advanced disease stages. 
  • 357
  • 21 Jun 2023
Topic Review
Matrix Metalloproteinases in Chronic Obstructive Pulmonary Disease
Matrix metalloproteinases (MMPs) are proteolytic enzymes that degrade proteins of the extracellular matrix and the basement membrane. Thus, these enzymes regulate airway remodeling, which is a major pathological feature of chronic obstructive pulmonary disease (COPD). Furthermore, proteolytic destruction in the lungs may lead to loss of elastin and the development of emphysema, which is associated with poor lung function in COPD patients.
  • 355
  • 10 Mar 2023
Topic Review
Thyroid Disorder and Dizziness in Humans
The regulation of thyroid hormone production is under the control of the hypothalamic–pituitary–thyroid (HPT) axis. TRH (Thyrotropin-Releasing Hormone), which is synthesized and secreted by the neurons of the paraventricular nuclei of the hypothalamus, stimulates the release of TSH (Thyroid-Stimulating Hormone) by the pituitary gland. TSH binds to its membrane receptor in the thyroid follicular cells and triggers the synthesis and secretion of the following thyroid hormones: Thyroxine (Tetraiodothyronine, T4) and T3 (Triiodothyronine). When the concentration of T4 and T3 in the blood increases, a negative feedback loop is set up to inhibit the pituitary response to TRH and decrease TSH secretion.
  • 351
  • 25 Jun 2023
Topic Review
Microbiome on Immunotherapy for Gastroesophageal Cancer
Esophageal cancer (EC) is a highly aggressive malignancy, comprising two main subtypes, esophageal squamous-cell carcinoma/ESCC and esophageal adenocarcinoma/EAC. Gastric cancer (GC) has been identified as a disease caused by a combination of genetic, molecular, and environmental factors, with H. pylori infection being the most common factor among them.
  • 351
  • 20 Oct 2023
Topic Review
SLC9B2 (NHA2/NHEDC2) in Male Fertility
The SLC9B2 gene encodes the NHA2 protein (also known as NHEDC2). While NHA2 has been shown to be important for regulating various aspects of physiology such as blood pressure, this protein has also been implicated as being important for male fertility in mice. What is known about NHA2 and its potentially important role in male fertility is emphasized.
  • 351
  • 26 Oct 2023
Topic Review
Hypoxia-Related Metabolic Responses of the Fish Heart
Hypoxia imposes conflicting demands on cardio-respiratory function. Being systemically O2 supply-dependent on cardiac output (CO) and arterial O2 concentration, fish can respond to and cope with hypoxia through cardio-respiratory adjustments to preserve systemic O2 delivery, thus maintaining aerobic metabolism, or by reducing O2 demands via anaerobic metabolism or metabolic depression. In 1986, Hochachka firstly proposed metabolic arrest, i.e., a simultaneous reduction in metabolic rate and metabolic demands, as a key adaptation to O2 deprivation in organisms capable of long-term anoxic survival.
  • 351
  • 28 Jan 2023
Topic Review
Hypothalamic Control of Circadian Homeostasis and Hormone Regulation
Hypothalamic hormone release functions through a cascade system induced by input received from higher brain centers responding to environmental information. These hormones travel through the hypothalamic-hypophyseal portal system to the pituitary to produce or inhibit hormones that are then transported throughout the body to interact with target organs.
  • 350
  • 02 Mar 2023
Topic Review
Dopaminergic Modulation of Prefrontal Cortex Inhibition
The prefrontal cortex is the highest stage of integration in the mammalian brain. Its functions vary greatly, from working memory to decision-making, and are primarily related to higher cognitive functions. This explains the considerable effort devoted to investigating this area, revealing the complex molecular, cellular, and network organization, and the essential role of various regulatory controls. In particular, the dopaminergic modulation and the impact of local interneurons activity are critical for prefrontal cortex functioning, controlling the excitatory/inhibitory balance and the overall network processing. Here will focus on the dopaminergic modulation of GABAergic inhibition, which plays a significant role in shaping prefrontal cortex activity.
  • 348
  • 12 May 2023
Topic Review
Concepts in the Two-Process Model of Sleep Regulation
The two-process model of sleep regulation has served as a conceptual framework in the last four decades for understanding sleep physiology. In the 1970s, long-term recordings of sleep in rats were obtained thanks to EEG telemetry. NonREM sleep and REM sleep were found to differ in their time course and response to light-dark protocols. There were indications for their coupling to the circadian system, in particular the light-dark and the dark-light transitions. With the advent of quantitative EEG analysis, slow-wave activity in nonREM sleep was recognized as a sleep-wake-dependent variable. The term “sleep homeostasis” was coined to specify the regulated balance between sleep and waking. The regulatory homeostatic process was designated as “Process S”. In the two-process model, its interaction with the circadian pacemaker “Process C” can account for sleep duration under various experimental protocols. Local, use-dependent slow-wave activity changes were demonstrated in both humans and rats by the selective, unilateral activation of a cortical region prior to sleep. Finding that rest in invertebrates has sleep-like regulatory properties opened a new realm of animal studies. Comparative sleep studies in a broad variety of animal species confirmed the validity of the basic concepts of the two-process model.
  • 348
  • 17 Jan 2024
Topic Review
Airway Smooth Muscle Calcium Handling Mechanisms and Estrogens
Cell calcium (Ca2+) homeostasis is maintained by a finely tuned Ca2+ signaling system made-up of numerous Ca2+ transporters (channels, exchangers, and pumps) regulating the influx and efflux of this cation from the cytoplasm to preserve its balance. Ca2+ homeostasis is essential for the cell. As a second messenger, Ca2+ signaling regulates various cellular processes that depend on the Ca2+ concentration. It is well known that Ca2+ regulates exocytosis, contraction, protein phosphorylation, dephosphorylation, metabolism, gene transcription, fecundation, cell proliferation, and even apoptosis. In the ASM, Ca2+ homeostasis keeps intracellular basal Ca2+ concentrations (b[Ca2+]i) at around 100–150 nM, while Ca2+ concentrations in the intracellular stores and extracellular space are higher (5–10 mM and 2 mM, respectively) creating a large chemical gradient in favor of Ca2+ influx into the cytosol. In order to regulate [Ca2+]i, numerous proteins exist to facilitate the cellular influx and efflux of Ca2+. Among the calcium-handling proteins, the voltage-dependent Ca2+ channels (VDCCs), store-operated Ca2+ channels (SOCCs), receptor-operated Ca2+ channel (ROCCs), transient receptor potential channels (TRPs), and the Na+/Ca2+ exchanger in its reverse form (NCXREV) as influx mechanisms located in the cellular membrane can be included. On the other hand, the Na+/Ca2+ Exchanger (NCX) and the plasma membrane Ca2+ ATPase (PMCA) are efflux mechanisms located in the cellular membrane.
  • 344
  • 15 May 2023
Topic Review
ClC-1 Chloride Channel Structure and Myotonia-Causing Mutations Update
Myotonia congenita is a hereditary muscle disease mainly characterized by muscle hyperexcitability, which leads to a sustained burst of discharges that correlates with the magnitude and duration of involuntary aftercontractions, muscle stiffness, and hypertrophy. Mutations in the chloride voltage-gated channel 1 (CLCN1) gene that encodes the skeletal muscle chloride channel (ClC-1) are responsible for this disease, which is commonly known as myotonic chloride channelopathy. The structure of the channel has been updated and the biophysical properties of the mutated channel have been explored and analyzed, providing important clues to the general function/dysfunction of the wild-type and mutated channels.
  • 343
  • 02 Nov 2023
Topic Review
Temozolomide and Autophagy
Temozolomide is an oral alkylating agent that is used as the first line treatment for glioblastoma multiform, and in recurrent anaplastic astrocytoma, as well as having demonstrable activity in patients with metastatic melanoma. However, as the case with other chemotherapeutic agents, the development of resistance often limits the therapeutic benefit of temozolomide, particularly in the case of glioblastoma. A number of resistance mechanisms have been proposed including the development of cytoprotective autophagy. Cytoprotective autophagy is a survival mechanism that confers upon tumor cells the ability to survive in a nutrient deficient environment as well as under external stresses, such as cancer chemotherapeutic drugs and radiation, in part through the suppression of apoptotic cell death.
  • 333
  • 01 Mar 2023
Topic Review
Mechanisms Involved in MIRI and Interactions with NLRP3
Myocardial ischemia-reperfusion injury (MIRI) is caused by several mechanisms, including the production of reactive oxygen species (ROS), altered cellular osmolarity, and inflammatory response. Calcium overload, altered oxygen levels, and mitochondrial ROS are also involved in these MIRI processes, resulting in the irreversible opening of the mitochondrial permeability transition pore (mPTP). These mechanisms and processes are associated with NLRP3 inflammasome priming and activation, which can also induce cell death by pyroptosis through the up-regulation of the caspase-1 pathway and IL-18 release. In addition, endothelial dysfunction, both in the presence and absence of MIRI, is also accompanied by altered oxygen levels, decreased nitric oxide production, and ROS overproduction, resulting in the expression of adhesion molecules and leukocyte infiltration in which the NLRP3 inflammasome plays a central role, thus contributing, through endothelial dysfunction, to the alteration of coronary flow, typical of ischemic heart disease. Given the intricate interrelationship between ROS and NLRP3, ROS inhibitors can reduce NLRP3 inflammasome activation, while NLRP3 inhibitors can reduce oxidative stress and inflammation. 
  • 333
  • 17 Jul 2023
Topic Review
KCa and Regulation of the Uteroplacental Circulation
Adequate uteroplacental blood supply is essential for the development and growth of the placenta and fetus during pregnancy. Aberrant uteroplacental perfusion is associated with pregnancy complications such as preeclampsia, fetal growth restriction (FGR), and gestational diabetes. The regulation of uteroplacental blood flow is thus vital to the well-being of the mother and fetus. Ca2+-activated K+ (KCa) channels of small, intermediate, and large conductance participate in setting and regulating the resting membrane potential of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) and play a critical role in controlling vascular tone and blood pressure. KCa channels are important mediators of estrogen/pregnancy-induced adaptive changes in the uteroplacental circulation. Activation of the channels hyperpolarizes uteroplacental VSMCs/ECs, leading to attenuated vascular tone, blunted vasopressor responses, and increased uteroplacental blood flow. However, the regulation of uteroplacental vascular function by KCa channels is compromised in pregnancy complications.
  • 331
  • 02 Feb 2023
Topic Review
Exertional Heat Illness Pathophysiology in Thoroughbred Racehorses
Exertional Heat Illness (EHI) occurs in all species where strenuous physical exertion takes place. It has been documented in human athletes, military personnel, firefighters and outdoor labourers, in racehorses and sporting horses, racing camels, and in working, sporting and even recreational dogs. The major symptoms of hyperthermia manifests as central nervous system (CNS) dysfunction which is typical across species, and EHI represents a significant welfare issue because it can cause significant morbidity and even fatality if allowed to progress untreated. The thoroughbred (TB) racehorse is at considerable risk because of the intensity of its exercise activity and its high rate of metabolic heat production.
  • 325
  • 17 Feb 2023
Topic Review
Underpin Sarcopenia, Cardiovascular and Metabolic Diseases
Worldwide, the main reason for all-cause mortality is attributed to non-communicable diseases, namely, cardiovascular disease (CVD) and metabolic diseases (MDs). CVD refers to conditions affecting the heart and blood vessels, such as coronary artery disease, heart failure and hypertension. MDs refer to disorders of processing nutrients and the use of energy. These conditions can include diabetes, obesity and metabolic syndrome, among others. Both CVD and MDs can have serious consequences, including heart attacks, stroke and organ damage. CVD remains the leading cause of death worldwide. 
  • 325
  • 29 Jun 2023
Topic Review
Alternative Organism Models for Retina Neuroregeneration
Unlike in vitro cell cultures that cannot mimic tissue homeostasis and physiology, 3D retinal organoids are relatively cheap models and have an undeniable complexity rate. However, they are challenging to isolate and maintain long enough to investigate complex processes such as inflammation and neovascularization. These disadvantages are exacerbated considering the retina, which is mainly due to the global complexity of this tissue. Several classic diagnostic techniques could be applied to retinal organ cultures, such as optical coherence tomography, which explores the morphological aspect of the retinal architecture, electroretinograms that record the electrical response of retinal cells, and microelectrode array recording, which stimulates and records the electrical activity of RGC. Several mammalian retinal organ cultures as alternative models are currently available and well established, including those derived from mice, rats, rabbits, cats, dogs, non-human primates, bovines, and pigs. They are excellent samples for the preliminary phase before the in vivo step and for therapy tests, although organ cultures for the study of complex retinal neurodegenerative pathologies such as diabetic retinopathy (DR), retinitis pigmentosa (RP), age-related macular degeneration, and glaucoma are not entirely reproducing the human condition. Although all the events occurring during the various steps of retinal neurodegenerative diseases, including the clinical progression, are not fully mimicked by a single animal, preclinical in vivo models provide important information on the molecular and cellular mechanisms at the basis of the neuronal impairment. Thus, multiple organisms, including non-mammalian ones, are crucial for validating the mechanisms involved in retinal pathologies and developing new therapeutic options.
  • 324
  • 28 Sep 2022
Topic Review
Dopamine Levels and Metabolism in the Heart
Dopamine has effects on the mammalian heart. These effects can include an increase in the force of contraction, and an elevation of the beating rate and the constriction of coronary arteries. Depending on the species studied, positive inotropic effects were strong, very modest, or absent, or even negative inotropic effects occurred.
  • 324
  • 06 Sep 2023
Topic Review
Nanoparticles for Brain Protection
Strokes rank as the second most common cause of mortality and disability in the human population across the world. Currently, available methods of treating or preventing strokes have significant limitations, primarily the need to use high doses of drugs due to the presence of the blood–brain barrier. In the last decade, increasing attention has been paid to the capabilities of nanotechnology. However, the vast majority of research in this area is focused on the mechanisms of anticancer and antiviral effects of nanoparticles.
  • 308
  • 29 Jan 2024
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