820 research outputs found
The Role of Biomarkers, Metabolomics, and COVID-19 in Venous Thromboembolism—A Review of Literature
In recent years, the field of venous thromboembolism has undergone numerous innovations, starting from the recent discoveries on the role of biomarkers, passing through the role of metabolomics in expanding our knowledge on pathogenic mechanisms, which have opened up new therapeutic targets. A variety of studies have contributed to characterizing the metabolic phenotype that occurs in venous thromboembolism, identifying numerous pathways that are altered in this setting. Among these pathways are the metabolism of carnitine, tryptophan, purine, and fatty acids. Furthermore, new evidence has emerged with the recent COVID-19 pandemic. Hypercoagulability phenomena induced by this viral infection appear to be related to altered von Willebrand factor activity, alteration of the renin-angiotensin-aldosterone system, and dysregulation of both innate and adaptive immunity. This is the first literature review that brings together the most recent evidence regarding biomarkers, metabolomics, and COVID-19 in the field of venous thromboembolism, while also mentioning current therapeutic protocols
The Natriuretic Peptide System: A Single Entity, Pleiotropic Effects
In the modern scientific landscape, natriuretic peptides are a complex and interesting network of molecules playing pleiotropic effects on many organs and tissues, ensuring the maintenance of homeostasis mainly in the cardiovascular system and regulating the water-salt balance. The characterization of their receptors, the understanding of the molecular mechanisms through which they exert their action, and the discovery of new peptides in the last period have made it possible to increasingly feature the physiological and pathophysiological role of the members of this family, also allowing to hypothesize the possible settings for using these molecules for therapeutic purposes. This literature review traces the history of the discovery and characterization of the key players among the natriuretic peptides, the scientific trials performed to ascertain their physiological role, and the applications of this knowledge in the clinical field, leaving a glimpse of new and exciting possibilities for their use in the treatment of diseases
Enhancing H2 production rate in PGM-free photoelectrochemical cells by glycerol photo-oxidation
The photo-oxidation of glycerol was carried out by using TiO2 NTs photoanodes and Ni foam as the cathode for the Hydrogen Evolution Reaction. The photoanodes were prepared by anodizing Ti foils and titanium felt and then annealed under air exposure. They were tested in acidic aqueous solution without and with the addition of glycerol. When glycerol was present, the hydrogen production rate increased and allowed the simultaneous production of high value added partial oxidation compounds, i.e. 1,3-dihydroxyacetone (DHA), and glyceraldehyde (GA). The highest H2 evolution and partial oxidation compounds production rates were obtained by using home prepared TiO2 nanotubes (TiO2 NTs) synthesized on Ti fiber felt as the photoanode with an irradiated area of 90 cm2. These photoanodes were found to be highly stable both from a mechanical and a chemical point of view, so they can be reused after a simple cleaning step
Blood cyanide determination in two cases of fatal imtoxication: comparison between headspace gas chromatography and a spectrophotometric method
Blood samples of two cases were analyzed preliminarily by a classical spectrophotometric method (VIS) and by an automated headspace gas chromatographic method with nitrogen-phosphorus detector (HS-GC \u2044 NPD). In the former, hydrogen cyanide (HCN) was quantitatively
determined by measuring the absorbance of chromophores forming as a result of interaction with chloramine T. In the automated HS-GC \u2044NPD method, blood was placed in a headspace vial, internal standard (acetonitrile) and acetic acid were then added. This resulted in cyanide being liberated as HCN. The spectrophotometric (VIS) and HS-GC\u2044NPD methods were validated on postmortem blood samples fortified with potassium cyanide in the ranges 0.5\u201310 and 0.05\u20135 lg \u2044 mL, respectively. Detection limits were 0.2 lg \u2044mL for VIS and 0.05 lg \u2044mL for HS-GC\u2044NPD. This work shows that results obtained by means of the two procedures were insignificantly different and that they compared favorably. They are suitable for rapid diagnosis of cyanide in postmortem cases
Lanthanide Identity Governs Guest-Induced Dimerization in LnIII[15-MCCuIIN(L-pheHA)-5])3+ Metallacrowns
Series of lanthanide-containing metallic coordination complexes are frequently presented as structurally analogous, due to the similar chemical and coordinative properties of the lanthanides. In the case of chiral (LnIII[15-MC (Formula presented.) N(L-pheHA)-5])3+ metallacrowns (MCs), which are well established supramolecular hosts, the formation of dimers templated by a dicarboxylate guest (muconate) in solution of neutral pH is herein shown to have a unique dependence on the identity of the MC's central lanthanide. Calorimetric data and nuclear magnetic resonance diffusion studies demonstrate that MCs containing larger or smaller lanthanides as the central metal only form monomeric host-guest complexes whereas analogues with intermediate lanthanides (for example, Eu, Gd, Dy) participate in formation of dimeric host-guest-host compartments. The driving force for the dimerization event across the series is thought to be a competition between formation of highly stable MCs (larger lanthanides) and optimally linked bridging guests (smaller lanthanides)
Atherosclerosis as an inflammatory disease. ,
In many ways, atherosclerosis is a chronic inflammatory disorder and this issue is confirmed by recent investigations of that have focused on inflammation, providing new insight into mechanisms of disease. Several recent studies have addressed the role of chemokines in leukocyte accumulation in atherosclerosis, extending our knowledge and understanding of the complex and cell type-specific functions of chemokines in atherosclerosis. Activated T-lymphocytes within the atherosclerotic vessel wall express the CD40 ligand surface molecule, known to play a major role in several immunological pathways. In addition to activated T-lymphocytes, functional CD40 and CD40L are coexpressed by human vascular endothelial cells, smooth muscle cells and human macrophages in vitro as well as in situ in human atherosclerotic lesions. Recent studies indicate that CD40L activates atheroma-associated cells by promoting the expression of molecules thought to be involved in atherosclerosis, such as adhesion molecules, cytokines, matrix metalloproteinases, and tissue factor. Atherosclerosis starts with an innate immune response involving the recruitment and activation of monocytes macrophages that respond to an excessive accumulation of modified lipids within the arterial wall, followed by an adaptive immune response involving antigen-specific T lymphocytes. Effector T cells recognize modified auto-antigens such as oxidized LDL and heat shock proteins (i.e. HSP-60) that are presented by antigen-presenting cells such as macrophages or dendritic cells. The accumulation of inflammatory cells within the arterial wall leads to local production of chemokines, interleukins and proteases that enhance the influx of monocytes and lymphocytes, thereby promoting the progression of atherosclerotic lesions Recent reports have helped explain some of these questions by pointing to a role of contact dependent interaction between CD40 and CD40 ligand (CD40L, renamed CD154) as a stimulus for atheroma-associated cells. Also Macrophages play important roles in the progression of atherosclerosis by exhibiting unique characteristics under the various stimuli, evolving the plaque instability, thrombus formation and remodeling. Macrophage recruitment by abnormal endothelium over developing atherosclerotic plaques, is aided by endothelial expression of adhesion molecules (ICAM-1, VCAM, ELAM). The knowledge of atherosclerosis as an inflammatory disease offers the opportunity to develop novel therapeutic strategies targeting the inflammatory component of the disease
Structural properties and anticoagulant/cytotoxic activities of heterochiral enantiomeric thrombin binding aptamer (TBA) derivatives
The thrombin binding aptamer (TBA) possesses promising antiproliferative properties. However, its development as an anticancer agent is drastically impaired by its concomitant anticoagulant activity. Therefore, suitable chemical modifications in the TBA sequence would be required in order to preserve its antiproliferative over anticoagulant activity. In this paper, we report structural investigations, based on circular dichroism (CD) and nuclear magnetic resonance spectroscopy (NMR), and biological evaluation of four pairs of enantiomeric heterochiral TBA analogues. The four TBA derivatives of the D-series are composed by D-residues except for one L-thymidine in the small TT loops, while their four enantiomers are composed by L-residues except for one D-thymidine in the same TT loop region. Apart from the left-handedness for the L-series TBA derivatives, CD and NMR measurements have shown that all TBA analogues are able to adopt the antiparallel, monomolecular, 'chair-like' G-quadruplex structure characteristic of the natural D-TBA. However, although all eight TBA derivatives are endowed with remarkable cytotoxic activities against colon and lung cancer cell lines, only TBA derivatives of the L-series show no anticoagulant activity and are considerably resistant in biological environments
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