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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.
  • 917
  • 03 May 2021
Topic Review
Vascular Endothelial Growth Factors
Vascular endothelial growth factors (VEGFs) are primary regulators of blood and lymphatic vessels. Hemangiogenic VEGFs (VEGF-A, PlGF, and VEGF-B) target mostly blood vessels, while the lymphangiogenic VEGFs (VEGF-C and VEGF-D) target mostly lymphatic vessels. Blocking VEGF-A is used today to treat several types of cancer (“antiangiogenic therapy”). However, in other diseases, it would be beneficial to do the opposite, namely to increase the activity of VEGFs. For example, VEGF-A could generate new blood vessels to protect from heart disease, and VEGF-C could generate new lymphatics to counteract lymphedema. Clinical trials that tried to stimulate blood vessel growth in ischemic diseases have been disappointing so far, and the first clinical trials targeting the lymphatic vasculature have progressed to phase II. Antiangiogenic drugs targeting VEGF-A such as bevacizumab or aflibercept neutralize the growth factor directly. However, since VEGF-C and VEGF-D are produced as inactive precursors, novel drugs against the lymphangiogenic VEGFs could also target the enzymatic activation of VEGF-C and VEGF-D. Because of the delicate balance between too much and too little vascular growth, a detailed understanding of the activation of the VEGF-C and VEGF-D is needed before such concepts can be converted into safe and efficacious therapies.
  • 3.2K
  • 30 Mar 2021
Topic Review
Inflammation in TGFβ-Dependent EMT
Epithelial–mesenchymal transition (EMT) is a complex cellular program known to be a crucial driver in the context of embryonic development, wound healing and tumour progression.
  • 761
  • 03 Mar 2021
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.
  • 4.2K
  • 01 Mar 2021
Topic Review
Cardiac Development
Cardiac development is a complex developmental process that is initiated soon after gastrulation, as two sets of precardiac mesodermal precursors are symmetrically located and subsequently fused at the embryonic midline forming the cardiac straight tube. Thereafter, the cardiac straight tube invariably bends to the right, configuring the first sign of morphological left–right asymmetry and soon thereafter the atrial and ventricular chambers are formed, expanded and progressively septated. As a consequence of all these morphogenetic processes, the fetal heart acquired a four-chambered structure having distinct inlet and outlet connections and a specialized conduction system capable of directing the electrical impulse within the fully formed heart.
  • 788
  • 26 Feb 2021
Topic Review
Congenital Malformations in Sea Turtles
Congenital malformations can lead to embryonic mortality in many species, and sea turtles are no exception. Genetic and/or environmental alterations occur during early development in the embryo, and may produce aberrant phenotypes, many of which are incompatible with life. Causes of malformations are multifactorial; genetic factors may include mutations, chromosomal aberrations, and inbreeding effects, whereas non-genetic factors may include nutrition, hyperthermia, low moisture, radiation, and contamination. It is possible to monitor and control some of these factors (such as temperature and humidity) in nesting beaches, and toxic compounds in feeding areas, which can be transferred to the embryo through their lipophilic properties.
  • 1.6K
  • 22 Feb 2021
Topic Review
PET for Microenvironment-Targeted Therapy
 Quantitative parameters of FDG-PET, such as SUV and TLG have been used to evaluate therapeutic response. Recent advancement in anti-cancer therapeutics showed that tumor response to molecular-targeted drugs and immune-checkpoint inhibitors is different from conventional chemotherapy in terms of temporal metabolic alteration and morphological change after the course of effective therapy. Metabolic changes and temporal enlargement due to immune cell infiltration seen after immune-checkpoint inhibitors, such as anti-programmed cell death-1 (PD-1) and anti-programmed cell death ligand 1 (PD-L1) antibodies facilitated the modification of conventional Response Evaluation Criteria in Solid Tumor and FDG-PET response evaluation criteria. Tumor microenvironment including cancer stem cells (CSCs) that is thought to be a root cause of tumor heterogeneity; is considered a target of novel and effective therapy.   Accumulation of FDG reflects glucose metabolism of both cancer cells and immunologically competent cells in the tumor microenvironment. Immunological reaction to the therapy differs among patients according to the individual immune function. Considering the heterogeneity of tumor tissue and individual variation in tumor response to immunotherapy, radiomics approach combines quantitative image features with deep learning algorithm have the potentials to improve response assessment in more personalized treatment.   Stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4)-targeted α-particle therapy has been introduced, because SDF-1/CXCR4 axis is known to increase epithelial-mesenchymal transition to facilitate invasion and metastasis, and regulate immune response by accelerating T cell proliferation as well as PD-1 and PD-L1 expression in cancer cells and cytotoxic T lymphocytes, respectively. Prominent energy profile and biological effect of α-particles are promising as an alternative in targeted radionuclide therapy (TRT). Radiation dosimetry according to the theranostics approach will permit accurate TRT and artificial intelligence-based treatment decision making and precise response evaluation would be a precision nuclear medicine in the future.
  • 851
  • 08 Feb 2021
Topic Review
Spinal-Deformities and Advancement in Corrective-Orthoses
Spinal deformity is an abnormality in the spinal curves and can seriously affect the activities of daily life. The conventional way to treat spinal deformities, such as scoliosis, kyphosis, and spondylolisthesis, is to use spinal orthoses (braces). Braces have been used for centuries to apply corrective forces to the spine to treat spinal deformities or to stabilize the spine during postoperative rehabilitation. Braces have not modernized with advancements in technology, and very few braces are equipped with smart sensory design and active actuation. There is a need to enable the orthotists, ergonomics practitioners, and developers to incorporate new technologies into the passive field of bracing. 
  • 2.0K
  • 30 Jan 2021
Topic Review
LNX/PDZRN E3 Ubiquitin Ligase Family
The ligand of Numb protein-X (LNX) family, also known as the PDZRN family, is composed of four discrete RING-type E3 ubiquitin ligases (LNX1, LNX2, LNX3, and LNX4), and LNX5 which may not act as an E3 ubiquitin ligase owing to the lack of the RING domain. 
  • 749
  • 31 Dec 2020
Topic Review
Lyme Disease
Lyme disease, or Lyme borreliosis, is an increasingly prevalent illness caused by several bacteria in the Borrelia genus. Lyme disease is an increasingly common bacterial illness that exists throughout the world. Current diagnostic methods for Lyme disease are ineffective at detecting the illness during its early stages - when it is easiest to treat; thus, the improvement of Lyme diagnostics is a popular area of research in many scientific fields.
  • 707
  • 16 Dec 2020
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