COVID-19 and the Renin-Angiotensin-Aldosterone System

Pathological Features and Neuroinflammatory Mechanisms of SARS-CoV-2 in the Brain and Potential Therapeutic Approaches

The number of deaths has been increased due to COVID-19 infections and uncertain neurological complications associated with the central nervous system. Post-infections and neurological manifestations in neuronal tissues caused by COVID-19 are still unknown and there is a need to explore how brainstorming promoted congenital impairment, dementia, and Alzheimer's disease. SARS-CoV-2 neuro-invasion studies in vivo are still rare, despite the fact that other beta-coronaviruses have shown similar properties. Neural (olfactory or vagal) and hematogenous (crossing the blood-brain barrier) pathways have been hypothesized in light of new evidence showing the existence of SARS-CoV-2 host cell entry receptors into the specific components of human nerve and vascular tissue. Spike proteins are the primary key and structural component of the COVID-19 that promotes the infection into brain cells. Neurological manifestations and serious neurodegeneration occur through the binding of spike proteins to ACE2 receptor. The emerging evidence reported that, due to the high rate in the immediate wake of viral infection, the olfactory bulb, thalamus, and brain stem are intensely infected through a trans-synaptic transfer of the virus. It also instructs the release of chemokines, cytokines, and inflammatory signals immensely to the blood-brain barrier and infects the astrocytes, which causes neuroinflammation and neuron death; and this induction of excessive inflammation and immune response developed in more neurodegeneration complications. The present review revealed the pathophysiological effects, molecular, and cellular mechanisms of possible entry routes into the brain, pathogenicity of autoantibodies and emerging immunotherapies against COVID-19.

Emergency Department Management of Hypertension in the Context of COVID-19

PURPOSE OF REVIEW

This review describes the relationship between COVID-19 and hypertension (HTN), and considerations for emergency medicine providers in the management of hypertensive patients during the COVID-19 pandemic.

RECENT FINDINGS

Hypertensive patients with COVID-19 have a higher risk of severe disease/complications, hospitalizations, intensive care unit (ICU) admissions, and mortality than non-hypertensive patients. Studies have also shown the importance of consideration of various demographic factors (such as older age) and socioeconomic factors that may confound these relationships. Despite concerns at the start of the pandemic that RAAS inhibiting antihypertension medications may contribute to worsened outcomes in COVID-19 patients, subsequent research has shown that use of ACEi/ARBs is associated with neutral or even improved COVID-19 outcomes. Socioeconomic factors must also be considered including patients' potential delay of health care due to fear of contracting COVID-19, loss of health insurance, and barriers to accessing primary care appointments for post-ED follow-up care. While there is mixed evidence on biological considerations for HTN care during the COVID-19 pandemic, the pandemic has undoubtedly been a major stressor and barrier to effective chronic disease management. Emergency medicine and other providers should consider this when evaluating acute care patients with a history of HTN or newly elevated blood pressure.

Immunometabolic Dysregulation at the Intersection of Obesity and COVID-19

Obesity prevails worldwide to an increasing effect. For example, up to 42% of American adults are considered obese. Obese individuals are prone to a variety of complications of metabolic disorders including diabetes mellitus, hypertension, cardiovascular disease, and chronic kidney disease. Recent meta-analyses of clinical studies in patient cohorts in the ongoing coronavirus-disease 2019 (COVID-19) pandemic indicate that the presence of obesity and relevant disorders is linked to a more severe prognosis of COVID-19. Given the significance of obesity in COVID-19 progression, we provide a review of host metabolic and immune responses in the immunometabolic dysregulation exaggerated by obesity and the viral infection that develops into a severe course of COVID-19. Moreover, sequela studies of individuals 6 months after having COVID-19 show a higher risk of metabolic comorbidities including obesity, diabetes, and kidney disease. These collectively implicate an inter-systemic dimension to understanding the association between obesity and COVID-19 and suggest an interdisciplinary intervention for relief of obesity-COVID-19 complications beyond the phase of acute infection.

COVID-19 and male reproductive system: pathogenic features and possible mechanisms

Multiorgan dysfunction is the main characteristic of severe COVID-19 patients and the involvement of male reproductive system may occur among these patients. Although there is a limited evidence to confirm the orchitis and virus presence in the semen of patients, there are concerns about the transmission of virus through the semen. In addition, reduced fertility or infertility can be seen as consequences of severe COVID-19 in recovered subjects. In this study, we aimed to review articles related to COVID-19 and male reproductive system to find the possible underlying mechanisms of SARS-CoV-2 in affecting male fertility. The following keywords of SARS-CoV-2, COVID-19, testis, orchitis, semen, angiotensin-converting enzyme 2 (ACE2), hypothalamic-pituitary-testicular (HPT) axis, Hypothalamus, etc., were defined to find the related publications from standard search engines, e.g., PUBMED, SCOPUS, Google Scholar. According to studies, COVID-19 occurs in severe patients as respiratory disease, along with multi-organ failure. The most important mechanisms are classified as direct and indirect pathogenesis of SARS-CoV-2. The presence of ACE2 on the cell surface of various cells in testis increases the risk of direct infection by this virus. SARS-CoV-2 also affects the testis through the cytokine storm. In addition, the important role of HPT axis dysregulation through impaired Leydig cells and hypothalamus should be considered. Using antiviral and immunomodulatory therapy can be harmful for testis function. Further investigations are required to investigate potential mechanisms of male infertility in survivals of COVID-19. Since involvement of testis is essential for fertility, increasing the knowledge of health system may improve the outcomes.

Concomitant use of dexamethasone and tetracyclines: a potential therapeutic option for the management of severe COVID-19 infection?

Introduction: The global coronavirus disease-2019 (COVID-19) pandemic has posed a critical challenge to the research community as well as to the healthcare systems. Severe COVID-19 patients are at a higher risk of developing serious complications and mortality. There is a dire need for safe and effective pharmacotherapy for addressing unmet needs of these patients. Concomitant use of dexamethasone and tetracyclines, by virtue of their immunomodulatory and other relevant pharmacological properties, offers a potential strategy for synergy aimed at improving clinical outcomes.Areas covered: Here we review the potential benefits of combining dexamethasone and tetracyclines (minocycline or doxycycline) for the management of severe COVID-19 patients. We have critically examined the evidence obtained from in silico, experimental, and clinical research. We have also discussed the plausible mechanisms, advantages, and drawbacks of this proposed combination therapy for managing severe COVID-19.Expert opinion: The concomitant use of dexamethasone and one of the tetracyclines among severe COVID-19 patients offers several advantages in terms of additive immunomodulatory effects, cost-effectiveness, wide-availability, and well-known pharmacological properties including adverse-effect profile and contraindications. There is an urgent need to facilitate pilot studies followed by well-designed and adequately-powered multicentric clinical trials to generate conclusive evidence related to utility of this approach.