Role of Enhancing Aerobic Capacity in Countering COVID-19-induced Liver Injury in Elderlies

COVID-19 is still a world disaster; however, its vaccination is globally available. Liver and gastrointestinal disturbances occur in patients infected with COVID-19 at varying incidences. Aging decreases the functions of the liver. Thus, the elderly have a weaker response to the COVID-19 virus. The COVID-19 virus affects the liver directly through direct and indirect mechanisms. It directly affects the renin-angiotensin system or indirectly causes sepsis, uncontrolled immune reactions, drug-related hepatic injury, and cytokine storm. Also, COVID-19 vaccines and anti-drugs have adverse effects on the liver too. Thus, this review explores the effect of enhancing aerobic capacity as a nonpharmacological intervention on decreasing COVID- 19-induced liver injury. Enhancing aerobic capacity decreases COVID-19-induced liver injury through the following: 1) downregulating systemic and tissue ACE/ANG II/AT1R axis, upregulating ACE2/ANG 1-7/Mas axis, and moving the renin-angiotensin system to the direction of the ACE2/ANG (1-7)/Mas axis, 2) Improving mitochondrial function and oxygenation to body and lung tissues, causing a decrease in harmful oxidative reactions, 3) Increasing the processing of accumulated free radicals and inhibiting the acute respiratory distress syndrome, 4) Acting as an antioxidant to protect the liver from oxidative stress, 5) Increasing the effect of antiviral drugs and COVID-19 vaccines, which improves the function of immune biomarkers, decreases the viral load, and increases the body's defense against the virus, 6) Decreasing coagulation abnormalities and thrombosis. In conclusion, enhancing aerobic capacity may be an efficient nonpharmacological intervention to decrease COVID-19-induced liver injury in elderlies and regenerate the liver to its normal status after being infected by the COVID-19 virus. It also helps to strengthen the body's immunity for better effects of both COVID-19 vaccination and drugs.

The ABCs of antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a thromboinflammatory syndrome characterized by thrombotic, microvascular, obstetric, or non-thrombotic events in the setting of persistent antiphospholipid antibodies (aPL), namely anticardiolipin antibody (aCL), anti-β2 glycoprotein-I antibody (aβ2GPI), and lupus anticoagulant (LA). The diagnosis of APS requires careful assessment of the aPL profile, the clinical phenotype, and additional risk factors. The standard management of aPL-related thrombosis is anticoagulation, which is not effective for microvascular and non-thrombotic events. In parallel to our improved understanding of aPL-related mechanisms, the role of immunosuppression has been increasingly investigated. In this review, we summarize the basic concepts and future perspectives in APS.

A Case of Intestinal Perforation Associated with Mesenteric Thrombosis due to Post-COVID-19 Syndrome

PURPOSE

We aimed to present a case who developed intestinal ischemia and associated perforation and abscess due to superior mesenteric vein (SMV) thrombosis caused by post-COVID-19 syndrome and discuss the preoperative computed tomography (CT) imaging findings used in diagnosis.

CASE REPORT

A 58-year-old patient presented to our clinic with a complaint of acute abdominal pain. His CT examination revealed thrombosis in SMV, congestion in the mesenteric venous structures, contamination in the mesentery and thickening and dilatation of the jejunal loops due to ischemia. The patient had a history of acute COVID-19 infection. He had typical COVID-19 pneumonia findings (peripheral ground-glass opacities in both lung parenchyma predominantly in the lower lobe) on the thorax CT at that time. He was followed up with anticoagulant therapy. During his follow-up, a thoracic and abdominal CT was performed due to recurrent acute abdominal findings. On thorax CT, there was a web-like filling defect consistent with pulmonary embolism, traction bronchiectasis consistent with late findings of COVID-19 pneumonia, and poorly circumscribed subpleural ground glass opacities. On abdominal CT, in addition to mesenteric ischemia findings, loss of wall integrity was observed in the jejunal loops due to perforation, and collection areas containing air consistent with an abscess. He was treated with small bowel resection and abscess drainage.

CONCLUSION

Patients with acute COVID-19 infection should be followed up for the early diagnosis of serious symptoms that may develop due to post-COVID-19 syndrome, and contrast-enhanced CT should be the imaging method of choice to detect possible mesenteric vascular thrombosis in patients with acute abdominal symptoms.

Circulating Exosomes and Their Role in Stroke

Stroke is an acute neurologic disorder which can be life-threatening if left untreated or diagnosed late. Various detecting techniques including neurologic imaging of the brain by computed tomography or magnetic resonance imaging can facilitate diagnosis of stroke. However, according to the recent advances in molecular detection techniques, new diagnostic and prognostic markers have emerged. Exosomes as an extra cellar particle are one of these markers which can have useful diagnostic, prognostic, and even therapeutic impact after stroke. We have previously discussed the role of exosomes in cardiovascular disease and in the present review we focus on the most common cerebrovascular disease. The aim of the present review is summarizing the recent diagnostic role of exosomes which are specifically secreted during a stroke and can guide clinicians to better diagnosis of stroke.

A Review on the Effects of New Anti-Diabetic Drugs on Platelet Function

BACKGROUND

Cardiovascular complications account for the majority of deaths caused by diabetes mellitus. Platelet hyperactivity has been shown to increase the risk of thrombotic events and is a therapeutic target for their prevention in diabetes. Modulation of platelet function by diabetes agents in addition to their hypoglycemic effects would contribute to cardiovascular protection. Newly introduced antidiabetic drugs of sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon like peptide-1 receptor agonists (GLP-1RA) and dipeptidyl peptidase-4 inhibitors may have anti-platelet effects, and in the case of SGLT2i and GLP-1RA may contribute to their proven cardiovascular benefit that has been shown clinically.

OBJECTIVE

Here, we reviewed the potential effects of these agents on platelet function in diabetes.

RESULTS AND CONCLUSION

GLP-1RA and DPP-4i drugs have antiplatelet properties beyond their primary hypoglycemic effects. Whilst we have little direct evidence for the antiplatelet effects of SGLT2 inhibitors, some studies have shown that these agents may inhibit platelet aggregation and reduce the risk of thrombotic events in diabetes.

Aptamers Which Target Proteins: What Proteotronics Suggests to Pharmaceutics

Aptamers represent a challenging field of research, relevant for diagnosis in macular degeneration, cancer, thrombosis and many inflammatory diseases, and promising in drug discovery and development. Their selection is currently performed by a stable in vitro technology, namely, SELEX. Furthermore, computationalstatistical tools have been developed to complement the SELEX selection; they work both in the preliminary stage of selection, by designing high affinity aptamers for the assigned target, and also in the final stage, analyzing the features of the best performers to implement the selection technique further. A massive use of the in silico approach is, at present, only restricted by the limited knowledge of the specific aptamer-target topology. Actually, only about fifty X-ray structures of aptamer-protein complexes have been experimentally resolved, highlighting how this knowledge has to be improved. The structure of biomolecules like aptamer-protein complexes can be represented by networks, from which several parameters can be extracted. This work briefly reviews the literature, discussing if and how general network parameters in the framework of Proteotronics and graph theory (such as electrical features, link number, free energy change, and assortativity), are important in characterizing the complexes, anticipating some features of the biomolecules. To better explain this topic, a case-study is proposed, constituted by a set of anti-angiopoietin (Ang2) aptamers, whose performances are known from the experiments, and for which two different types of conformers were predicted. A topological indicator is proposed, named Möbius (M), which combines local and global information, and seems able to discriminate between the two possible types of conformers, so that it can be considered as a useful complement to the in vitro screening for pharmaceutical aims.

Antiplatelet Therapy in Acute Coronary Syndromes. Lights and Shadows of Platelet Function Tests to Guide the Best Therapeutic Approach

The key role of platelets in pathophysiology of Acute Coronary Syndromes (ACS) has been well recognized. Platelet activation and aggregation, together with tissue factor-pathway activation, lead to acute thrombus formation in the coronary vessels at sites of plaque rupture. Thus, antiplatelet therapy with drugs able to interfere with platelet activation/aggregation represents a cornerstone of ACS treatment in intensive care units and catheterisation labs. Several observational studies have described that residual high platelet reactivity, despite antiplatelet therapy, is associated with increased risk of nonfatal Myocardial Infarction (MI), definite/probable stent thrombosis and cardiovascular mortality. Thus, assessment of platelet function with reliable and reproducible platelet function tests might be crucial to identify patients at high risk of thrombosis or not responding to ongoing antiplatelet strategies. However, despite this promising background, some randomized clinical trials have failed to demonstrate improvement in outcomes when using platelet function tests for clinical decision-making. This review, after describing platelet biology and pathophysiology of ACS, briefly considers the drugs currently approved for use in patients with ACS or treated by the percutaneous coronary intervention (PCI). Finally, we provide an updated overview of the current methods to evaluate platelet reactivity in the clinical setting of ACS illustrating their potential advantages/limitations in current clinical practice.

Potential Therapeutic Applications of P2 Receptor Antagonists: From Bench to Clinical Trials

BACKGROUND

Extracellular purines and pyrimidines have important physiological functions in mammals. Purines and pyrimidines act on P1 and P2 purinergic receptors, which are widely expressed in the plasma membrane in various cell types. P2 receptors act as important therapeutic targets and are associated with several disorders, such as pain, neurodegeneration, cancer, inflammation, and thrombosis. However, the use of antagonists for P2 receptors in clinical therapy, with the exception of P2Y12, is a great challenge. Currently, many research groups and pharmaceutical companies are working on the development of specific antagonist molecules for each receptor subtype that could be used as new medicines to treat their respective disorders.

OBJECTIVE

The present review compiles some interesting findings on the application of P2 receptor antagonists in different in vitro and in vivo experimental models as well as the progress of advanced clinical trials with these compounds.

CONCLUSION

Despite all of the exciting results obtained on the bench, few antagonists of P2 receptors advanced to the clinical trials, and once they reach this stage, the effectiveness of the therapy is not guaranteed, as in the example of P2X7 antagonists. Despite this, P2Y12 receptor antagonists have a history of success and have been used in therapy for at least two decades to prevent thrombosis in patients at risk for myocardial infarctions. This breakthrough is the motivation for scientists to develop new drugs with antagonistic activity for the other P2 receptors; thus, in a matter of years, we will have an evolution in the field of purinergic therapy.

A Brief Review of Cardiovascular Diseases, Associated Risk Factors and Current Treatment Regimes

Cardiovascular diseases (CVDs) are the leading cause of premature death and disability in humans and their incidence is on the rise globally. Given their substantial contribution towards the escalating costs of health care, CVDs also generate a high socio-economic burden in the general population. The underlying pathogenesis and progression associated with nearly all CVDs are predominantly of atherosclerotic origin that leads to the development of coronary artery disease, cerebrovascular disease, venous thromboembolism and, peripheral vascular disease, subsequently causing myocardial infarction, cardiac arrhythmias or stroke. The aetiological risk factors leading to the onset of CVDs are well recognized and include hyperlipidaemia, hypertension, diabetes, obesity, smoking and, lack of physical activity. They collectively represent more than 90% of the CVD risks in all epidemiological studies. Despite high fatality rate of CVDs, the identification and careful prevention of the underlying risk factors can significantly reduce the global epidemic of CVDs. Beside making favorable lifestyle modifications, primary regimes for the prevention and treatment of CVDs include lipid-lowering drugs, antihypertensives, antiplatelet and anticoagulation therapies. Despite their effectiveness, significant gaps in the treatment of CVDs remain. In this review, we discuss the epidemiology and pathology of the major CVDs that are prevalent globally. We also determine the contribution of well-recognized risk factors towards the development of CVDs and the prevention strategies. In the end, therapies for the control and treatment of CVDs are discussed.

Novel Oral Anticoagulants in Peripheral Artery Disease: Current Evidence

BACKGROUND

Peripheral artery disease is a common manifestation of systemic atherosclerosis which strongly correlates to cardiovascular morbidity and mortality. In addition, the progression of peripheral artery disease leads to an increased risk of limb loss. In order to reduce these events, the benchmark of treatment and research over the last years has been the antiplatelet therapy which aims at inhibition of platelet aggregation. Over the last years, new studies combining antiplatelet agents in different therapeutic schemes have been proven efficacious. Unfortunately, patients remain still at high risk of CV events. Novel Oral Anticoagulants have been introduced as alternatives to warfarin, in the prevention and treatment of venous thromboembolism. The rationale of using medication which acts on platelet activation and the coagulation pathway of thrombosis has led investigators to examine the role of Noac's in preventing CV events in patients with peripheral artery disease, stable or unstable.

METHODS

The aim of this study is to review the current evidence with respect to recently published studies concerning the use of Novel anticoagulants in peripheral artery disease.

RESULTS

The Compass trial has shown that a combination of rivaroxaban with traditional therapy may produce promising results in reducing amputation rates, stroke, cardiac events, and mortality, however, there are still safety issues with bleeding requiring acute care. The ePAD study has provided us with insight concerning safety and efficacy after peripheral angioplasty or stenting and actually the need for further research. The Voyager Pad study, following the steps of Compass, is studying the effect and safety of the addition of rivaroxaban to traditional therapy in the highest risk population aka patients undergoing peripheral revascularization. The evidence concerning patients with concomitant atrial fibrillation appears to be insufficient, however, recent guidelines propose the use of novel oral anticoagulants.

CONCLUSION

For the time being, novel oral anticoagulants in combination with aspirin may provide an alternative treatment in PAD, however, it is deemed necessary to identify patient subgroups who will benefit the most.

Crosstalk between Platelet and Bacteria: A Therapeutic Prospect

Platelets are typically recognized for their roles in the maintenance of hemostasis and vascular wall repair to reduce blood loss. Beyond hemostasis, platelets also play a critical role in pathophysiological conditions like atherosclerosis, stroke, thrombosis, and infections. During infection, platelets interact directly and indirectly with bacteria through a wide range of cellular and molecular mechanisms. Platelet surface receptors such as GPIbα, FcγRIIA, GPIIbIIIa, and TLRs, etc. facilitate direct interaction with bacterial cells. Besides, the indirect interaction between platelet and bacteria involves host plasma proteins such as von Willebrand Factor (vWF), fibronectin, IgG, and fibrinogen. Bacterial cells induce platelet activation, aggregation, and thrombus formation in the microvasculature. The activated platelets induce the Neutrophil Extracellular Traps (NETs) formation, which further contribute to thrombosis. Thus, platelets are extensively anticipated as vital immune modulator cells during infection, which may further lead to cardiovascular complications. In this review, we cover the interaction mechanisms between platelets and bacteria that may lead to the development of thrombotic disorders. Platelet receptors and other host molecules involved in such interactions can be used to develop new therapeutic strategies to combat against infection-induced cardiovascular complications. In addition, we highlight other receptor and enzyme targets that may further reduce infection-induced platelet activation and various pathological conditions.

Thrombotic Events in Homozygotes with a Proven or Highly Probable Arg304Gln Factor VII Mutation (FVII Padua)1): Only Limited Replacement Therapy is Needed in Case of Surgery

OBJECTIVE

To investigate the prevalence of thrombotic events among patients with proven or highly probable homozygosis for the Arg304Gln (Factor VII Padua) defect or compound heterozygosis containing the Arg304Gln mutation.

METHODS

Homozygotes and compound heterozygotes proven by molecular studies to have the Arg304Gln mutation were gathered from personal files and from two PubMed searches. In addition, patients with probable homozygosis on the basis of clotting tests (discrepancies among Factor VII activity levels according to the tissue thromboplastin used) were also gathered.

RESULTS

30 proven homozygotes and 17 probable ones were gathered together with 8 compound heterozygotes. In the latter use, the associated mutation was Cys135Arg (twice), Gly180Arg, Arg304Trp, Arg315Trp, His348Gln, Gly365Cys. The prevalence of venous thrombotic events was 16.6, 11.8 and 11.1 percent, respectively for the three groups of patients. Heterozygotes showed no thrombotic event. The difference for proven homozygotes was statistically significant, while for the other groups only a trend was present.

CONCLUSION

proven homozygous or compound heterozygous patients with the Arg304Gln mutation showed a higher than expected incidence of thrombotic events. The same is true for probable cases gathered only on the basis of clotting tests. These patients, because of their frequent lack of bleeding and for their relatively high prevalence of thrombosis should probably receive only limited replacement therapy in case of surgical procedures.

Extensively Thrombosed Ectatic Circumflex Coronary Artery Fistula Presenting as Acute Coronary Syndrome

Background: Coronary artery fistula (CAF) is an abnormal communication between the termination of a coronary artery or its branches and a cardiac chamber, a great vessel or other vascular structure. Symptomatic patients with large CAF should undergo surgical or percutanous closure of the fistula at the drainage site while still the debate on closing asymptomatic CAF and re-opening symptomatic occluded CAF is ongoing.

Advances in the Development of Novel Factor Xa Inhibitors: A Patent Review

Development of new anticoagulants has been in constant demand throughout the world due to increasing rate of morbidity and mortality caused by thrombotic diseases. Factor Xa (FXa), one of the enzymes and validated target for anticoagulation, regulates the production of thrombin in the coagulation cascade. The importance of oral FXa inhibitors like rivaroxaban, apixaban and edoxaban in thromboembolic conditions is well supported by increasing number of patents and research publications during the recent years. Direct FXa inhibitors as antithrombotic agents offer selective, efficacious and orally active therapy with respect to the other traditional anticoagulants. Newly developed patented molecules are mainly structural bioisosteres of existing drugs and have exhibited better efficacy and safety profile. Development of antidotes for oral direct FXa inhibitors is in pipeline and their expected approval for therapeutic purposes will be further beneficial to anticoagulation therapy. This review is mainly focused on industrial and academic patents on the discovery of direct FXa inhibitors. The review covers patented compounds from December 2011 till date, describing various structural modifications along with biological activity data and advances in the process and formulation technologies of the reported FXa inhibitors.

Small Peptides as Modulators of Serine Proteases

Serine proteases play critical roles in many physiological and pathological processes, and are proven diagnostic and therapeutic targets in a number of clinical indications. Suppression of the aberrant proteolytic activities of these proteases has been clinically used for the treatments of relevant diseases. Polypeptides with 10-20 residues are of great interests as medicinal modulators of serine proteases, because these peptides demonstrate the characteristics of both small molecule drugs and macromolecular drugs. In this review, we summarized the recent development of peptide-based inhibitors against serine proteases with potent inhibitory and high specificity comparable to monoclonal antibodies. In addition, we also discussed the strategies of enhancing plasma half-life and bioavailability of peptides in vivo, which is the main hurdle that limits the clinical translation of peptide-based drugs. This review advocates new avenue for the development of effective serine protease inhibitors and highlights the prospect of the medicinal use of these inhibitors.

Targeting the Microcirculation by Indole-3-carbinol and Its Main Derivate 3,3,'-diindolylmethane: Effects on Angiogenesis, Thrombosis and Inflammation

The pharmacological targeting of microcirculatory dysregulations is a therapeutic strategy for the treatment of numerous pathological conditions, such as cancer, thrombosis and inflammation. A promising candidate for this purpose is indole-3-carbinol (I3C), a phytochemical compound of cruciferous vegetables, and its main derivate 3,3,'-diindolylmethane (DIM). As summarized in this review, I3C and DIM affect multiple molecular and cellular processes within the microcirculation due to their pleiotropic action profile. These include angiogenesis, leukocyte-endothelial cell interaction, cytokine and reactive oxygen species (ROS) production, thrombus formation and microvascular leakage. Hence, I3C may serve as a lead compound for the future chemical synthesis of novel drugs that exert comparable beneficial effects while exhibiting an improved bioavailability.

Is there a Role for Oral Triple Therapy in Patients with Acute Coronary Syndromes Without Atrial Fibrillation?

BACKGROUND

Acute Coronary Syndrome (ACS) patients, despite treatment with Dual Anti- Platelet Therapy (DAPT), have up to 10% risk of recurrent Major Adverse Cardiac Events (MACE) in the short term.

METHODS

Here we review studies using more potent antithrombotic agent combinations to reduce this risk, namely Triple Therapy (TT) with the addition of an oral anticoagulant, PAR-1 antagonist, or cilostazol to DAPT (mainly aspirin and clopidogrel), and discuss the limitations of trials to date.

RESULTS

Generally speaking, TT leads to an increase in bleeding. Vorapaxar showed a signal for reducing ischaemic events, but increased intracranial haemorrhage 3-fold in the subacute phase of ACS, although remains an option for secondary prevention beyond the immediate subacute phase, particularly if prasugrel or ticagrelor are not available. Non-Vitamin K Oral Anticoagulants (NOACs) all increased bleeding, with only modest reduction in MACE noted with low dose rivaroxaban. Rivaroxaban can be considered combined with aspirin and clopidogrel in ACS patients at high ischaemic and low bleeding risk, without prior stroke/TIA. The combination of P2Y12 inhibitor and NOAC, without aspirin, looks promising. DAPT may be replaced, not by TT, but by dual therapy comprising a NOAC with a P2Y12 inhibitor.

CONCLUSION

More potent antithrombotic regimens increase bleeding and should only be considered on an individual basis, after careful risk stratification. Accurate risk stratification of ACS patients, for both ischaemic and bleeding risk, is essential to allow individualised treatment.

Immune-Inflammatory Activation in Acute Coronary Syndromes: A Look into the Heart of Unstable Coronary Plaque

In the last twenty years, our comprehension of the molecular mechanisms involved in the formation, progression and complication of atherosclerotic plaque has advanced significantly and the main role of inflammation and immunity in this phenomenon is now largely accepted. Accumulating evidence highlight the crucial role of different inflammatory and immune cells, such as monocytes and T-lymphocytes, in the pathophysiology of atherosclerotic lesion, particularly in contributing to its com-plications, such as rupture or ulceration. According to the new terminology, “vulnerable plaque” identi-fies an inflamed atherosclerotic lesion that is particularly prone to rupture. Once disrupted, prothrom-botic material is exposed to the flowing blood, thus activating coagulation cascade and platelet aggrega-tion, ultimately leading to acute thrombus formation within the coronary vessel. To date this is the key event underlying the clinical manifestations of acute coronary syndromes (ACS).

The degree of vessel occlusion (complete vs. incomplete) and the time of blood flow cessation will define the severity of clinical picture. This phenomenon seems to be the final effect of a complex inter-action between different local and systemic factors, involving the degree of inflammation, type of cells infiltration and the rheological characteristics of blood flow at the site of plaque rupture, thrombogenic substrates within the atherosclerotic lesion and different soluble mediators, already present or acutely released in the circulating blood. This article will review currently available data on the pathophysiology of ACS, emphasizing the immunological and inflammatory aspects of vulnerable plaque. We may pos-tulate that intraplaque antigens and local microenvironment will define the immune-inflammatory re-sponse and cells phenotype, thus determining the severity of clinical manifestations.