Case Series: Hypercalcemia From Granulomatous Silicosis Developing After COVID-19 Infection.

Hypercalcemia is one of the most commonly encountered laboratory abnormalities in clinical medicine. Various causes have been well established. However, it is likely that the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), may be a newly found cause of this frequent finding, especially amongst those with a history of cosmetic surgery, specifically by means of silicone injection. In this case series, we describe 2 patients presenting with symptomatic hypercalcemia likely from their prior silicone injections. Interestingly, each patient only developed symptoms of hypercalcemia following infection with SARS-CoV-2.

A case of isolated sinus bradycardia as an unusual presentation of adrenal insufficiency.

INTRODUCTION: Sinus bradycardia is a common entity encountered in clinical practice. The differential diagnosis is quite broad; it can be an incidental finding in otherwise healthy adults or the first clue to a lethal pathology. CASE PRESENTATION: This case highlights a patient who presented with symptomatic sinus bradycardia, which resulted in syncope requiring admission for permanent pacemaker implantation and later found to have an underlying adrenal insufficiency (AI). Patient's underlying hyponatremia was corrected but bradycardia persisted and after the initiation of steroids, bradycardia resolved. Therefore, the likely culprit for bradycardia was AI. DISCUSSION: Multiple disease processes that manifest with sinus bradycardia are commonly due to the increased vagal tone or the presence of intrinsic conduction disorders. Sinus bradycardia is a common clinical finding with a broad differential including intrinsic and extrinsic causes of sinus node dysfunction or AV block. CONCLUSION: It is imperative for clinicians to be aware of rare etiologies for underlying symptomatic bradycardia. While extremely effective at preventing symptomatic bradycardia, avoiding a pacemaker by correcting the underlying etiology of symptomatic bradycardia may improve quality of life and avoid an unnecessary procedure.

Undecaprenol kinase: Function, mechanism and substrate specificity of a potential antibiotic target.

The bifunctional undecaprenol kinase/phosphatase (UdpK) is a small, prokaryotic, integral membrane kinase, homologous with Escherichia coli diacylglycerol kinase and expressed by the dgkA gene. In Gram-positive bacteria, UdpK is involved in the homeostasis of the bacterial undecaprenoid pool, where it converts undecaprenol to undecaprenyl phosphate (C55P) and also catalyses the reverse process. C55P is the universal lipid carrier and critical to numerous glycopolymer and glycoprotein biosynthetic pathways in bacteria. DgkA gene expression has been linked to facilitating bacterial growth and survival in response to environmental stressors, as well being implicated as a resistance mechanism to the topical antibiotic bacitracin, by providing an additional route to C55P. Therefore, identification of UdpK inhibitors could lead to novel antibiotic treatments. A combination of homology modelling and mutagenesis experiments on UdpK have been used to identify residues that may be involved in kinase/phosphatase activity. In this review, we will summarise recent work on the mechanism and substrate specificity of UdpK.