Topic Review
The Plant Response to Mechanical Stress
Mechanical stimuli, together with the corresponding plant perception mechanisms and the finely tuned thigmomorphogenetic response, has been of scientific and practical interest since the mid-17th century. As an emerging field, there are many challenges in the research of mechanical stress. Indeed, studies on different plant species (annual/perennial) and plant organs (stem/root) using different approaches (field, wet lab, and in silico/computational) have delivered insufficient findings that frequently impede the practical application of the acquired knowledge. 
  • 584
  • 21 Feb 2023
Topic Review
The Na+/H+ Exchangers in Cardiac Physiology Regulation
The Na+/H+ exchangers (NHEs) are membrane transporters that exchange one intracellular pro-ton for one extracellular Na+. The first discovered NHE isoform, NHE1, is expressed almost ubiquitously in all tissues, especially in the myocardium. During myocardial ische-mia-reperfusion, NHE1 catalyzes increased uptake of intracellular Na+, which in turn leads to Ca2+ overload and subsequently myocardial injury. Numerous preclinical research has shown that NHE1 is involved in cardiac hypertrophy and heart failure, but the exact molecular mecha-nisms remain elusive.
  • 308
  • 27 Sep 2022
Topic Review
The Microbiota–Gut–Brain Axis
The microbiota–gut system can be thought of as a single unit that interacts with the brain via the “two-way” microbiota–gut–brain axis. Through this axis, a constant interplay mediated by the several products originating from the microbiota guarantees the physiological development and shaping of the gut and the brain. The modification of the composition of the microbiota destroys the bottom-to-top communication that ultimately influences brain motor, sensory, and cognitive functions, maintains brain homeostasis and/or contributes to the onset of pathological conditions. Elucidating the interplay between the gut microbiota and the central nervous system, and the role of microbiota in neuroinflammation, will lead to a better understanding of many neurodegenerative diseases pathogeneses, and, hopefully, to the development of new preventing or therapeutic strategies.
  • 487
  • 11 Oct 2021
Topic Review
The Intravitreal Space of the Eye
The intravitreal space comprises the majority of the eye’s volume and is located behind the lens of the eye. The vitreous chamber of the eye is mostly filled with a gel-like solution called the vitreous body. The vitreous body is 98.5–99.7% water containing salt soluble proteins and hyaluronic acid.
  • 344
  • 05 May 2022
Topic Review
The Cat Mandible
The cat mandible is small and has some peculiarities relative to the dentition (only three incisors, a prominent canine, two premolars and one molar); a conical and horizontally oriented condyle, and a protudent angular process in its ventrocaudal part. Most of the body of the mandible is occupied by the mandibular dental roots and the mandibular canal that protects the neurovascular supply: the inferior alveolar artery and vein, and the inferior alveolar nerve that exits the mandible rostrally as the mental nerves. They irrigate and innervate all the teeth and associated structures such as the lips and gingiva. Tooth roots and the mandibular canal account for up to 70% of the volume of the mandibular body. Consequently, when fractured it is difficult to repair without invading the dental roots or vascular structures.
  • 3.2K
  • 01 Mar 2021
Topic Review
The Biological Basis for Antioxidant Therapy
Reactive oxygen species (ROS) are a class of highly reactive free radicals, such as hydroxyl radical (•OH), the superoxide radical (O2•−) and hydrogen peroxide (H2O2). The high intracellular ROS level-induced oxidative stress leads to the upregulation of antioxidant capacity to maintain redox homeostasis by metabolic rerouting or activation of genetic programs.
  • 647
  • 06 Jul 2022
Topic Review
Telocytes in the Rainbow Trout Intestinal Stem-Cell Niche
Histological and ultrastructural studies revealed peculiar mesenchymal cells adjacent to the epithelium that generated an intricate mesh spanning from the folds’ base to their apex. Their voluminous nuclei, limited cytoplasm and long cytoplasmic projections characterized them as telocytes (TCs). 
  • 340
  • 10 Feb 2022
Topic Review
T-Cell Receptor Signalosome
Human immunodeficiency virus type-1 (HIV-1) can undergo either a lytic pathway to cause productive systemic infection or enter a latent state in which the integrated provirus remains transcriptionally silent for decades. The ability to latently infected T-cells enables HIV-1 to establish persistent infections in resting memory CD4+ T-lymphocytes which become reactivated following disruption or cessation of intensive drug therapy. Maintenance of viral latency occurs through epigenetic and non-epigenetic mechanisms. Epigenetic mechanisms of HIV latency regulation involve deacetylation and methylation of histone proteins within Nucleosome 1 (nuc -1) at the viral long terminal repeats (LTR) such that inhibition of histone deacetyltransferase and histone lysine methyltransferase activities, respectively, reactivates HIV from latency. Non-epigenetic mechanisms involve nuclear restriction of critical cellular transcription factors such as Nuclear factor-kappa Beta (NF-kB) or Nuclear factor of activated T-cells (NFAT) which activate transcription from the viral LTR, limiting nuclear levels of viral transcription transactivator protein Tat and its cellular co-factor; positive transcription elongation factor b (P-TEFb) which together regulate HIV transcriptional elongation. The T-cell receptor (TCR) activation efficiently induces NF-kB, NFAT, and activator protein 1 (AP-1) transcription factors through multiple signal pathways and how these factors efficiently regulate HIV LTR transcription through the non-epigenetic mechanism. Elongation factor P-TEFb induced through an extracellular signal-regulated kinase (ERK) dependent mechanism regulates HIV transcriptional elongation before Tat is synthesized and the role of AP-1 in the modulation of HIV transcriptional elongation through functional synergy with NF-kB. The TCR signaling induces critical posttranslational modifications of the Cyclin-dependent kinase 9 (CDK9) subunit of P-TEFb which enhances interactions between P-TEFb and viral Tat protein and the resultant enhancement of HIV transcriptional elongation.
  • 674
  • 13 Aug 2020
Topic Review
Surgical Management of Rectal Cancer
Successful oncologic resection in rectal cancer relies on the surgical tenants of wide local excision of the disease to establish clear margin status and resection of adequate lymph nodes for staging. The introduction of, and adherence to, complete total mesorectal excision, which is the resection of the total mesorectal envelope containing the local lymphatic drainage of the rectum, has contributed a large part to the improved operative outcomes and long-term survival for rectal cancer patients. Notably, total mesorectal excision has produced a notable reduction in rectal cancer recurrence by 30 to 40%.
  • 422
  • 06 Apr 2022
Topic Review
Surfactant and the Glycocalyx
Gas exchange in the lung takes place via the air-blood barrier in the septal walls of alveoli. The tissue elements that oxygen molecules have to cross are the alveolar epithelium, the interstitium and the capillary endothelium. The epithelium that lines the alveolar surface is covered by a thin and continuous liquid lining layer. Pulmonary surfactant acts at this air-liquid interface. By virtue of its biophysical and immunomodulatory functions, surfactant keeps alveoli open, dry and clean. What needs to be added to this picture is the glycocalyx of the alveolar epithelium. Here, we briefly review what is known about this glycocalyx and how it can be visualized using electron microscopy. The application of colloidal thorium dioxide as a staining agent reveals differences in the staining pattern between type I and type II alveolar epithelial cells and shows close associations of the glycocalyx with intraalveolar surfactant subtypes such as tubular myelin. These morphological findings indicate that specific spatial interactions between components of the surfactant system and those of the alveolar epithelial glycocalyx exist which may contribute to the maintenance of alveolar homeostasis, in particular to alveolar micromechanics, to the functional integrity of the air-blood barrier, to the regulation of the thickness and viscosity of the alveolar lining layer, and to the defence against inhaled pathogens. Exploring the alveolar epithelial glycocalyx in conjunction with the surfactant system opens novel physiological perspectives of potential clinical relevance for future research.
  • 814
  • 03 May 2021
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