SARS-CoV-2 induced myocarditis: Current knowledge about its molecular and pathophysiological mechanisms

The existence of an inflammatory process in the heart muscle, related to a progressive worsening of myocardialfunction, different etiopathogenetic mechanisms concur and often overlap, thus making the diagnosis and the therapeuticapproach complex. As the COVID-19 pandemic progresses, the effects of the disease on the organ systems and inparticular on the cardiovascular system are becoming more and more profound. Cardiac involvement is a well-knownevent with a high percentage of findings in the heart’s magnetic field, even in asymptomatic areas. There arenumerous uncertainties regarding their evolution, in the long and short term, due not only to a difficult to determinethe varied clinical expression and the rarely performed intramyocardial biopsy which additionally presents diagnosticproblems but also in part to different clinical prognosis. Today, the new SARS-CoV-2 virus that uses the angiotensinconverting enzyme 2 (ACE2) which is present at high levels in myocardial cells as its entrance it can create evensevere heart injury. The pathophysiology in all of these cases can involve multiple immune and non-immunemechanisms within organs and vessels and can be occur in the clinical phases. Possible mechanisms of direct andindirect myocardial infarction in patients with COVID-19 include additional lesion and oxygen-rich and generalizedinflammation response with myocardial immune hyperactivity (myocarditis). Therefore, these can occur through theexcessive release of cytokines, the presence of thrombocytopenia, endocrine damage, heart failure, arrhythmias andmore. Patients can show average signs of myocardial damage, and some develop spontaneous cardiac complications,such as heart failure, arrhythmias and, rarely, rare cardiogenic disorders. Pathophysiology in all of these may involvemultiple mechanisms within the cytokine cephalic membrane, endocrine damage and thrombogenicity. The diagnosisof this myocardial injuri is mainly based on the myocardial enzyme troponin. This viewpoint paper explains today’sknowledge on viral myocarditis, in particular that from SARS-CoV-2 infection, if there is a connection with otherpossible biomolecular pathogenetic factors that can influence its natural course. In fact, it is for this reason that thepathogenetic mechanisms are analyzed and described. At the same time, its possible interaction with other parametersthat are documented risk factors for cardiovascular disease was examined. Although these biomolecular findings weremainly related to necrotic parts of the myocardium, it is important to recognize that myocardial damage early for abetter approach and prognosis.     

Atomic force microscope (AFM) combined with the ultramicrotome: a novel device for the serial section tomography and AFM/TEM complementary structural analysis of biological and polymer samples

A new device (NTEGRA Tomo) that is based on the integration of the scanning probe microscope (SPM) (NT‐MDT NTEGRA SPM) and the Ultramicrotome (Leica UC6NT) is presented. This integration enables the direct monitoring of a block face surface immediately following each sectioning cycle of ultramicrotome sectioning procedure. Consequently, this device can be applied for a serial section tomography of the wide range of biological and polymer materials. The automation of the sectioning/scanning cycle allows one to acquire up to 10 consecutive sectioned layer images per hour. It also permits to build a 3‐D nanotomography image reconstructed from several tens of layer images within one measurement session. The thickness of the layers can be varied from 20 to 2000 nm, and can be controlled directly by its interference colour in water. Additionally, the NTEGRA Tomo with its nanometer resolution is a valid instrument narrowing and highlighting an area of special interest within volume of the sample. For embedded biological objects the ultimate resolution of SPM mostly depends on the quality of macromolecular preservation of the biomaterial during sample preparation procedure. For most polymer materials it is comparable to transmission electron microscopy (TEM). The NTEGRA Tomo can routinely collect complementary AFM and TEM images. The block face of biological or polymer sample is investigated by AFM, whereas the last ultrathin section is analyzed with TEM after a staining procedure. Using the combination of both of these ultrastructural methods for the analysis of the same particular organelle or polymer constituent leads to a breakthrough in AFM/TEM image interpretation. Finally, new complementary aspects of the object's ultrastructure can be revealed.     

Structurally fixed modes or systems described by Rosenbrock's polynomial matrices

A full characterization of structurally fixed modes for systems described by Rosenbrock's polynomial matrices is given. The constraints imposed on the feedback structure are quite general, so that the decentralized-control problem can be viewed as a particular case. The results are obtained in the digraph-theory framework and provide computationally efficient tests.     

DETERMINATION OF PRACTICALLY SIGNIFICANT DIFFERENCES IN THE SENSORILY PERCEIVED CONSISTENCY OF SEMILIQUID FOODS1

The consistency of commercial salad dressing, chocolate pudding and mustard samples before and after controlled disruption was assessed by squeezing flow viscometry and evaluated sensorily by an untrained panel. The instrumental parameters were the apparent stress at 1.5 and 1.0 mm height and the apparent residual stress after 60 and 120 s relaxation (at 1.0 mm height). The panelists were asked to identify the sample(s) with the stronger consistency in a triangular test. The percent correct identifications was plotted against the difference in the magnitude of the instrumental parameters and their ratios. The scatter of these plots suggests that the effective stimulus for consistency perception was primarily the overall resistance to deformation or flow and to a much lesser extent to more subtle rheological characteristics like the ‘degree of solidity'. In the range of consistencies examined, the detection thresholds were on the order of 0.5‐0.7 kPa and 0.4‐0.6 kPa at 1.0 and 1.5 mm height, respectively. They corresponded to stress ratios on the order of 0.75‐0.85. Results of this kind will enable setting objective standards for the consistency of commercial semi liquid foods and tolerance margins to deviations from them.     

ABSENCE OF PROTEOLYSIS IN PURIFIED MYOFIBRILS OF POSTSPAWNED HAKE (MERLUCCIUS HUBBSI MARINI) DURING IN VITRO STORAGE AT 37C

The biochemical behavior of myofibrils from postspawned hake during in vitro storage at 37C was investigated. SDS‐PAGE, densitometric analysis of the band areas corresponding to the major myofibrillar proteins, and TCA soluble peptides determination showed no evidence of proteolysis in myofibrils after 44 h of incubation either in presence or in absence of a cocktail of protease inhibitors (1 mMPMSF+1mMiodoacetic acid + 1mM of EDTA). The absence of proteolysis in stored postspawned hake myofibrils contrasts with the autolysis in those from prespawned fish previously reported, indicating an influence of the reproductive cycle on the proteolytic activity closely associated to myofibrils.     

DETECTION OF VIBRIO ALGINOLYTICUS AND VIBRIO PARAHAEMOLYTICUS IN SHELLFISH SAMPLES USING COLLAGENASE-TARGETED MULTIPLEX-PCR

The increase of Vibrio infections especially associated with the consumption of contaminated seafood and fish underlines the necessity of an efficient monitoring system for Vibrio spp. supported by appropriate detection tools both in food products and in clinical samples. The aim of this study was the evaluation of the reliability of the collagenase‐targeted multiplex‐polymerase chain reaction (m‐PCR) for the detection of Vibrio alginolyticus, Vibrio cholerae and Vibrio parahaemolyticus in shellfish samples enriched in alkaline peptone water (APW). The coupling of a pre‐enrichment phase of the samples with the specificity of the PCR‐based assay was applied successfully to the detection of V. alginolyticus and V. parahaemolyticus, demonstrating that collagenase‐target m‐PCR may be used as a valid molecular target to discriminate the three Vibrio species.