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Functions of the Cardiovascular System
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
Cardiac muscle operates as a functional syncytium. It is not a true syncytium (a mass of protoplasm with many nuclei forming one cell), because each myocardial cell has its own nucleus within its own membrane. Cardiac muscle functions as a syncytium due to the presence of low-resistance connections between adjacent cells, and when an action potential is generated, the atria or the ventricles contract together.
Long-Term Glucose Infusions in the Treatment of Fetal Growth Retardation
Published in Asim Kurjak, John M. Beazley, Fetal Growth Retardation: Diagnosis and Treatment, 2020
The placentae were studied in cooperation with Leipzig University.24 The average proportion of ripe, predegenerative, and degenerative syncytium was assessed in enzyme-incubated, toluidine-blue stained semithin sections. In the placenta of healthy fetuses the share of ripe syncytium is significantly greater than in those of SFD fetuses.25 It is also known that there is a positive correlation between the estriol values, HPL values, and the proportion of ripe syncytium.26
Autoimmunity and Immune Pathological Aspects of Virus Disease
Published in Irun R. Cohen, Perspectives on Autoimmunity, 2020
H. Wege, R. Dörries, P. Massa, R. Watanabe
Within the CNS, virus spreads predominantly via cell to cell contact. Lytic infection of a few neurons may have severe consequences, since those specialized cells are not replaced by division. Neurons interact by many synapses; their axons and dentritic processes form highly elongated and branched networks. Indispensable for the proper function of neurons in signal transmission is the ensheathment of axons with densely packed myelin lamellae produced by oligodendrocytes. A single oligodendrocyte can wrap myelin internodes to many axons. Oligodendrocytes and neurons are strongly dependent on the metabolic coupling to astrocytes because the myelin compartments are separated from each other by tight junctions. Astrocytes form a functional syncytium due to many gap junctions which allow the exchange of substances important for nutrition, growth, and regulation. Such gap junctions connect also astrocytes to oligodendrocytes.11
Preexisting antibodies targeting SARS-CoV-2 S2 cross-react with commensal gut bacteria and impact COVID-19 vaccine induced immunity
Published in Gut Microbes, 2022
Liqiu Jia, Shufeng Weng, Jing Wu, Xiangxiang Tian, Yifan Zhang, Xuyang Wang, Jing Wang, Dongmei Yan, Wanhai Wang, Fang Fang, Zhaoqin Zhu, Chao Qiu, Wenhong Zhang, Ying Xu, Yanmin Wan
To probe the potential antigens that might induce the P144 binding antibodies, we isolated 6 mAbs from two naïve SPF mice (one C57BL/6J mouse and one BALB/c mouse) with high levels of preexisting S2-specific antibody responses. The results of microscale thermophoresis (MST) assays showed that the binding affinities with S2 protein were similar among the 6 mAbs (F5, 2.07 μM; H9, 0.98 μM; E10, 3.53 μM; G13, 2.10 μM; M3, 1.46 μM; G18, 2.25 μM) (Fig. S6). Five of these mAbs recognized P144 solely (Fig. S7A), while one mAb (clone M3) bound with P144 and P103 simultaneously (Fig. S7B). Results of competitive ELISA showed that the minimal epitopes varied slightly among the five P144-specific mAbs, especially at the C-terminal of P144 (Fig. S7A). The neutralizing potentials of these isolated monoclonal antibodies were evaluated using a pseudo-virus-based neutralization assay. Our results showed that these monoclonal antibodies exhibited limited neutralizing activity against 5 SARS-CoV-2 variants (Fig. S8), which might be partially explained by their relatively low affinities to S2 protein (Fig. S6). We also evaluated the activities of the mAbs in inhibiting spike protein mediated cell fusion according to a previously described method.39 The data showed that 6 mAbs significantly reduced syncytium formation at concentration of 10 μg/ml as compared to the IgG (Fig. S9).
COVID-19 during Pregnancy and Postpartum:
Published in Journal of Dietary Supplements, 2022
Sreus A. G. Naidu, Roger A. Clemens, Peter Pressman, Mehreen Zaigham, Kelvin J. A. Davies, A. Satyanarayan Naidu
Macro-pinocytosis and viral uptake: Macro-pinocytosis is exploited by many viral pathogens for cell entry. In SARS CoV, S-protein mediates interaction with receptors on adjacent cells, resulting in cell fusion and syncytium formation. Syncytium formation is a cytopathic effect (plasma membrane changes) consistent with macro-pinocytosis that increases cell-to-cell spreading of the virus (Yamada et al. 2009). Macro-pinocytosis is a type of endocytosis that is morphologically defined by the presence of membranous extensions of outwardly polymerizing actin termed membrane ruffles. Membrane ruffles nonspecific vesicles that surround and internalize fluid cargo into large vesicles or macro-pinosomes (Kerr and Teasdale 2009). An active replicating virus could induce macro-pinocytosis. LF inhibits macro-pinocytosis and impairs viral replication and cell-cell fusion (Freeman et al. 2014).
Suggestions for Combatting COVID-19 by Natural Means in the Absence of Standard Medical Regimens
Published in Journal of the American College of Nutrition, 2021
Harry G. Preuss, Okezie I. Aruoma
When the pandemic arose, Dr. Preuss dug into his files and found some preliminary in vitro work concerning their antiviral potential that had been performed but never published. Some success was discovered for both agents against the lipid encapsulated respiratory syncytial virus (RSV). A viral syncytial assay was established using a HEp-2 culture assay based on the concept that when an RSV infects human lung epithelial cells (monolayer), it replicates and invades the adjoining or surrounding cells. A syncytium is formed when infected cells fuze. These infected centers can be visually examined directly or with a phase contrast microscope. Accordingly, effects of oregano oil and monolaurin in comparison with Ribavirin, an antiviral drug on the infection and the development of syncytia were conducted (Table 2).