Lipopolysaccharides (LPS) from Gram-negative bacteria prime human polymorphonuclear neutrophils (PMNs) via multicomponent receptor cluster including CD14 and MD-2·TLR4 for the enhanced release of reactive oxygen species (ROS) were triggered by bacterial derived peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP). In this study, we investigated the impact of CD14 on LPS-induced priming of human PMNs for fMLP-triggered ROS generation (respiratory or oxidative) burst. Monoclonal antibodies against human CD14 (mAbs) as well as isotype-matched IgG2a did not influence significantly fMLP-triggered ROS production from LPS-unprimed PMNs. Anti-CD14 mAbs (clone UCHM-1) attenuated LPS-induced priming of PMNs as it had been mirrored by fMLP-triggered decrease of ROS production. Similar priming activity of S-LPS or Re-LPS from Escherichia coli for fMLP-triggered ROS release from PMNs was found. Obtained results suggest that glycosylphosphatidylinositol-anchored CD14 is the key player in LPS-induced PMN priming for fMLP-triggered ROS production. We believe that blockade of CD14 on the cell surface and clinical use of anti-CD14 mAbs or their Fab fragments may diminish the production of ROS and improve outcomes during cardiovascular diseases manifested by LPS-induced inflammation.
At the end of 2019, a new coronavirus infection occurred in the People’s Republic of China with an epicentre in the city of Wuhan. On February 11th, 2020, the World Health Organization assigned the official name of the infection caused by the new coronavirus – COVID-19. COVID-19 has affected people from all over the world given that the infection was noted in 200 countries resulting in annunciation of the pandemic situation. Human corona viruses cause mild to moderate respiratory infections. At the end of 2002, a new coronavirus appeared (SARS-CoV), the causal agent of atypical pneumonia, which caused acute respiratory distress syndrome (ARDS). The initial stage of COVID-19 infection is the penetration of SARS-CoV-2 into target cells that have angiotensin converting enzyme type II receptors. The virus enters the body through the respiratory tract and interacts primarily with toll-like receptors (TLRs). The events in SARS-Cov-2 induced infection follow the next scenario: epithelial cells via TLRs recognize and identify SARS-Cov-2, and after that the information is transmitted to the transcriptional NF-κB, which causes expression of the corresponding genes. Activated in this way, the epithelial cells begin to synthesize various biologically active molecules. The results obtained on preclinical material indicate that ROS generation increases and the antioxidant protection decreases, which plays a major role in the pathogenesis of SARS-CoV, as well as in the progression and severity of this respiratory disease.
N-methyl-D-aspartate (NMDA) receptors belong to the group of inotropic glutamate receptors, which are found in rat cardiomyocytes.Aim. To evaluate the influence of a non-competitive antagonist of NMDA-receptors — МК-801, separately or in combination with glutamate and/or glycine, on cardiodynamic parameters, coronary flow and oxidative stress biomarkers in isolated rat heart.Materials and methods. 40 Wistar albino rats were divided into 4 groups (10 rats per group). Aorta of isolated rat heart was cannulated and perfused retrogradely by Krebs-Henseleit buffer in the Langendorf mode. Group 1 received МК-801 (50 µmol/l), group 2 received МК-801 and glycine (100 µmol/l), group 3 received МК-801 and glutamate (100 µmol/l) and group 4 received МК-801, glutamate and glycine. Parameters of cardiac dynamics and coronary blood flow were registered during the last minute of tested substance infusion (E) and at the point when artery perfusate samples were taken at the end of the control period (C). The difference between two points (C and E) was calculated and expressed in percent with a standard deviation.Results. Group 1 demonstrated the most prominent decrease of peak left ventricle (LV) pressure increase velocity (–47.59 ± 5.65)%, systolic and diastolic LV pressure: (–45.18 ± 4.87)% and (–37.24 ± 5.15)%, respectively and cardiac rate: (–28.63 ± 3.00)%. The most significant decrease of minimal LV pressure increase velocity was observed in group 2: (–47.43 ± 5.68)%, decrease of coronary blood flow — in group 3: (–23.02 ± 2.49)%. The most significant decline of oxidative stress biomarkers — nitrite and hydrogen peroxide — was observed in group 3: (–29.24 ± 2,70)% and (–23.43 ± 3.15)%, respectively; of superoxide anion radical (O2–) — in group 2: (–55.72 ± 6.90)%, of lipid peroxidation index — in group 1: (–35.77 ± 4.49)%.Conclusion. Administration of МК-801 results in a statistically significant decrease of cardiac dynamic parameters and lipid peroxidation index, compared to MK-801 in combination with glutamate and/or glycine.
Currently, septic shock remains an unresolved public health problem that leads to serious epidemiological, economic and social problems. Septic shock is a common hemodynamic disorder caused by the interaction between pathogenic microbes and host cells, resulting in developing hypoxia, severe metabolic disorders and multiple organ failure. By now, no unified concept for pathophysiology of septic shock are available. However, the aforementioned data prove that one of the key arms in the pathogenesis is endothelial dysfunction and associated ischemic disorders. In the clinical course of septic shock, three stages are distinguished: the stage of compensation, decompensation as well as the stage of irreversible disorders. The initial stage, or the stage of compensation, is characterized by the activated inflammatory response against infectious agents. Clinically, this stage is characterized by the development of warm shock: fever, dermal hyperemia, hyperventilation, increased cardiac output, and tachycardia. The second stage in developing septic shock is characterized by arising cold shock as a consequence of escalating heart and respiratory failure. The final stage is the development of multiple organ failure manifested by emerging shock organs. Multiple organ failure occurs due to microthrombosis and increasing ischemia, which leads to hypoxia and development of mitochondrial dysfunction in immune cells. At this stage patients are characterized by the progressive cyanosis, developing anuria and intestinal obstruction, as well as altered mental status. Laboratory and instrumental diagnostics of septic shock is a promising approach to examine septic shock. The level of serum C-reactive protein, lactate, and proinflammatory cytokines are not highly specific diagnostic parameters of septic shock, because they can be found in any inflammatory process. Today, the promising diagnostic markers are pentraxin-3, high-density lipoproteins, and phosphatidylcholine. The severity of septic shock can be assessed by determining blood schistocytes, central venous pressure, and the ratio of venous-arterial CO2 and arterial-venous O2 pressure. The following diagnostic methods can be used to determine multiple organ failure: level of serum proenkephalin A119159 and heparin-binding protein; echocardiography, troponin I concentration and N-terminal pro-b-type natriuretic peptides; measuring activity of the renin-angiotensin-aldosterone system. Here we discuss the key aspects of pathogenesis, clinical picture and morphological changes of septic shock. The promising methods for diagnosing the disease and its complications have been studied.
One of proof mechanism elements on civil cases are proof methods, many of which treat various scientific spheres. At the same time the speech can go about proof methods which are not put in a procedural form. In this case methods of proof join in the proof mechanism by means of the legal proceedings conducted by participants of evidentiary activity. Object of research of the present article is application dialectic, logical and psychological methods of proof on civil cases. The author investigates use in civil and arbitration processes of methods of similarity and distinction, the accompanying changes, the rest, a ratio of the argument and proof, deduction and induction, belief, questions and answers, and some other.
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