Digital Pathology Initiatives and Experience of a Large Academic Institution During the Coronavirus Disease 2019 (COVID-19) Pandemic.

CONTEXT.­: Pathology practices have begun integrating digital pathology tools into their routine workflow. During 2020, the coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged as a pandemic, causing a global health crisis that significantly affected the world population in several areas, including medical practice, and pathology was no exception. OBJECTIVE.­: To summarize our experience in implementing digital pathology for remote primary diagnosis, education, and research during this pandemic. DESIGN.­: We surveyed our pathologists (all subspecialized) and trainees to gather information about their use of digital pathology tools before and during the pandemic. Quality assurance and slide distribution data were also examined. RESULTS.­: During the pandemic, the widespread use of digital tools in our institution allowed a smooth transition of most clinical and academic activities into remote with no major disruptions. The number of pathologists using whole slide imaging (WSI) for primary diagnosis increased from 20 (62.5%) to 29 (90.6%) of a total of 32 pathologists, excluding renal pathology and hematopathology, during the pandemic. Furthermore, the number of pathologists exclusively using whole slide imaging for primary diagnosis also increased from 2 (6.3%) to 5 (15.6%) during the pandemic. In 35 (100%) survey responses from attending pathologists, 21 (60%) reported using whole slide imaging for remote primary diagnosis following the Centers for Medicare and Medicaid Services waiver. Of these 21 pathologists, 18 (86%) responded that if allowed, they will continue using whole slide imaging for remote primary diagnosis after the pandemic. CONCLUSIONS.­: The pandemic served as a catalyst to pathologists adopting a digital workflow into their daily practice and realizing the logistic and technical advantages of such tools.

Isolation and Assessment of Pancreatic Islets Versus Dispersed Beta Cells: A Straightforward Approach to Examine Cell-Cell Communication.

Islets of Langerhans, found in the pancreas, are microorgans essential for glucose homeostasis within the body. Many cells are found with an islet, such as beta cells (~70%), alpha cells (~20%), delta cells (~5%), F cells (~4%), and epsilon cells (1%), each with its own unique function. To better understand the roles of these cells and how cell communication alters their function, several techniques have been established such as islet isolation and beta cell dispersion. Here we describe how to isolate primary rodent islets, disperse pancreatic islets, measure intracellular calcium, and use immunofluorescent staining to distinguish beta cells and alpha cells.

Intact pancreatic islets and dispersed beta-cells both generate intracellular calcium oscillations but differ in their responsiveness to glucose.

Pancreatic islets produce pulses of insulin and other hormones that maintain normal glucose homeostasis. These micro-organs possess exquisite glucose-sensing capabilities, allowing for precise changes in pulsatile insulin secretion in response to small changes in glucose. When communication among these cells is disrupted, precision glucose sensing falters. We measured intracellular calcium patterns in 6-mM-steps between 0 and 16 mM glucose, and also more finely in 2-mM-steps from 8 to 12 mM glucose, to compare glucose sensing systematically among intact islets and dispersed islet cells derived from the same mouse pancreas in vitro. The calcium activity of intact islets was uniformly low (quiescent) below 4 mM glucose and active above 8 mM glucose, whereas dispersed beta-cells displayed a broader activation range (2-to-10 mM). Intact islets exhibited calcium oscillations with 2-to-5-min periods, yet beta-cells exhibited longer 7-10 min periods. In every case, intact islets showed changes in activity with each 6-mM-glucose step, whereas dispersed islet cells displayed a continuum of calcium responses ranging from islet-like patterns to stable oscillations unaffected by changes in glucose concentration. These differences were also observed for 2-mM-glucose steps. Despite the diversity of dispersed beta-cell responses to glucose, the sum of all activity produced a glucose dose-response curve that was surprisingly similar to the curve for intact islets, arguing against the importance of "hub cells" for function. Beta-cells thus retain many of the features of islets, but some are more islet-like than others. Determining the molecular underpinnings of these variations could be valuable for future studies of stem-cell-derived beta-cell therapies.

STEAP4: its emerging role in metabolism and homeostasis of cellular iron and copper.

Preserving energy homeostasis in the presence of stressors such as proinflammatory cytokines and nutrient overload is crucial to maintaining normal cellular function. Six transmembrane epithelial antigen of the prostate 4 (STEAP4), a metalloreductase involved in iron and copper homeostasis, is thought to play a potentially important role in the cellular response to inflammatory stress. Genome-wide association studies have linked various mutations in STEAP4 with the development of metabolic disorders such as obesity, metabolic syndrome and type 2 diabetes. Several studies have shown that expression of Steap4 is modulated by inflammatory cytokines, hormones and other indicators of cellular stress and that STEAP4 may protect cells from damage, helping to maintain normal metabolic function. STEAP4 appears to be particularly relevant in metabolically oriented cells, such as adipocytes, hepatocytes and pancreatic islet cells. These cells struggle to maintain their function in iron or copper overloaded states, presumably due to increased oxidative stress, suggesting STEAP4's role in metal homeostasis is critical to the maintenance of cellular homeostasis in general, and in preventing the onset of metabolic disease. In this review, we explore genetic associations of STEAP4 with metabolic disorders, and we examine STEAP4 tissue expression, subcellular localization, regulation, structure and function as it relates to metabolic diseases. We then examine how STEAP4's role as a regulator of cellular iron and copper may relate to type 2 diabetes.