Current medicinal chemistry
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Cardiac troponins (cTn) are considered to be the 'gold standard' biomarker for the diagnosis of acute coronary syndrome (ACS); a pathological spectrum which includes cardiac ischemia, angina, myocardial infarction and ultimately cardiac failure. The growing evidence base for the diagnostic and prognostic use of cTn in ACS has resulted in a universal redefinition of acute myocardial infarction (AMI). Recently a number of immunoassays with claims of superior sensitivity have been produced. ⋯ It is unknown if such mild elevations in cTn detected by sensitive assays are of clinical concern. What is certain is that AMI remains a clinical not a biochemical diagnosis and interpretation of cTn concentrations should be made according to the clinical context. This review highlights the development of the sensitive assays, documents their analytical and clinical performance and reviews the usefulness of cTn elevation in non-ACS conditions.
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Enzymes belonging to the PLA(2) superfamily catalyze the hydrolysis of unsaturated fatty acids from the sn-2 position of glycerol moiety of neural membrane phospholipids. The PLA(2) superfamily is classified into cytosolic PLA(2) (cPLA(2)), calcium-independent PLA(2) (iPLA(2)), plasmalogen-selective PLA(2) (PlsEtn-PLA(2)) and secretory PLA(2) (sPLA(2)). PLA(2) paralogs/splice variants/isozymes are part of a complex signal transduction network that maintains cross-talk among excitatory amino acid and dopamine receptors through the generation of second messengers. ⋯ In contrast, studies using a selective iPLA(2) inhibitor, bromoenol lactone, or antisense oligonucleotide indicate that iPLA(2) is an important "housekeeping" enzyme under basal conditions, whose activity is required for the prevention of vacuous chewing movements, a rodent model for tardive dyskinesia, and deficits in the prepulse inhibition of the auditory startle reflex, a common finding in schizophrenia. These studies support the view that PLA(2) activity may not only play a crucial role in neurodegeneration but depending on the isoform, could also be essential in prevention of neuropsychiatric diseases. The findings could open new doors for understanding and treatment of neurodegenerative and neuropsychiatric diseases.
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Chronic and acute overproduction of reactive oxygen species (ROS) under pathophysiologic conditions forms an integral part of the development of cardiovascular diseases (CVD), and in particular atherosclerosis. These ROS are released from different sources, such as xanthine oxidase, lipoxygenase, nicotinamide adenine dinucleotide phosphate oxidase, the uncoupling of nitric oxide synthase and, in particular, mitochondria. Endothelial dysfunction, characterized by a loss of nitric oxide (NO) bioactivity, occurs early on in the development of atherosclerosis, and determines future vascular complications. ⋯ Mitochondrial oxidative stress damage and dysfunction contribute to a number of cell pathologies that manifest themselves through a range of conditions. This review considers the process of atherosclerosis from a mitochondrial perspective, and assesses strategies for the targeted delivery of antioxidants to mitochondria that are currently under development. We will provide a summary of the following areas: the cellular metabolism of reactive oxygen species (ROS) and its role in pathophysiological processes such as atherosclerosis; currently available antioxidants and possible reasons for their efficacy and inefficacy in ameliorating oxidative stress-mediated diseases; and recent developments in mitochondrially-targeted antioxidants that concentrate on the matrix-facing surface of the inner mitochondrial membrane in order to protect against mitochondrial oxidative damage, and their therapeutic potential as a treatment for atherosclerosis.
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Micro- and macrovascular complications are major causes of disability and death in patients with diabetes mellitus. Functional impairment of endothelial activity precedes the development of morphological alterations during the progression of diabetes. This endothelial dysfunction results from reduced bioavailability of the vasodilator nitric oxide (NO), mainly due to accelerated NO degradation by reactive oxygen species (ROS). ⋯ Novel therapeutic approaches designed to inhibit AGEs formation, reduce PKC activation, decrease inflammatory signals and restore the ox/redox balance of endothelium may be predicted to ameliorate vascular function in diabetic state. This review summarizes the current knowledge on the most important mechanisms involved in endothelial dysfunction during diabetes. In addition, novel therapeutic strategies that may result from recently identified targets are also described.
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Eosinophils are major pro-inflammatory cells that make a major contribution to diseases that affect the upper and lower airways, skin and gastrointestinal tract. Interleukin (IL)-5 is central to their maturation and release from the bone marrow together with their subsequent accumulation and activation in the tissues. Mepolizumab is a humanized monoclonal antibody (mAb) with potent IL-5 neutralizing effects that represents a potential treatment for eosinophilic diseases. ⋯ More recently two studies, one in in patients with refractory eosinophilic asthma with a history of recurrent severe exacerbations and the other in patients with persistent sputum eosinophilia and symptoms despite systemic treatment with prednisone treatment, reported that monthly intravenous mepolizumab reduced sputum/blood eosinophilia, asthma exacerbations together with improvments in quality of life. Mepolizumab also appears to be an effective therapy for hypereosinophilic syndrome while other trials have shown efficacy of mepolizumab therapy in eosinophilic esophagitis. This review will consider the current status of the clinical development of mepolizumab for diseases with a significant eosinophilic component to their pathology.