Human amylin-derived oligomers and aggregates are believed to play an important role in the pathogenesis of type II diabetes mellitus (T2DM). In addition to amylin-evoked cell attrition, T2DM is often accompanied by elevated serum copper levels. Although previous studies have shown that human amylin, in the course of its aggregation, produces hydrogen peroxide (H2O2) in solution, and that this process is exacerbated in the presence of copper(II) ions (Cu2+), very little is known about the mechanism of interaction between Cu2+ and amylin in pancreatic β-cells, including its pathological significance. Hence, in this study we investigated the mechanism by which Cu2+ and human amylin catalyze formation of reactive oxygen species (ROS) in cells and in vitro, and examined the modulatory effect of Cu2+ on amylin aggregation and toxicity in pancreatic rat insulinoma (RIN-m5F) β-cells. Our results indicate that Cu2+ interacts with human and rat amylin to form metalo-peptide complexes with low aggregative and oxidative properties. Human and non-amyloidogenic rat amylin produced minute (nM) amounts of H2O2, the accumulation of which was slightly enhanced in the presence of Cu2+. In a marked contrast to human and rat amylin, and in the presence of the reducing agents glutathione and ascorbate, Cu2+ produced μM concentrations of H2O2 surpassing the amylin effect by several fold. The current study shows that human and rat amylin not only produce but also quench H2O2, and that human but not rat amylin significantly decreases the amount of H2O2 in solution produced by Cu2+ and glutathione. Similarly, human amylin was found to also decrease hydroxyl radical formation elicited by Cu2+ and glutathione. Furthermore, Cu2+ mitigated the toxic effect of human amylin by inhibiting activation of pro-apoptotic caspase-3 and stress-kinase signaling pathways in rat pancreatic insulinoma cells in part by stabilizing human amylin in its native conformational state. This sacrificial quenching of metal-catalyzed ROS by human amylin and copper’s anti-aggregative and anti-apoptotic properties suggest a novel and protective role for the copper–amylin complex.

Native electrospray ionization (ESI) mass spectrometry (MS) is often used to monitor noncovalent complex formation between peptides and ligands. The relatively low throughput of this technique, however, is not compatible with extensive screening. Laser ablation electrospray ionization (LAESI) MS combined with ion mobility separation (IMS) can analyze complex formation and provide conformation information within a matter of seconds. Islet amyloid polypeptide (IAPP) or amylin, a 37-amino acid residue peptide, is produced in pancreatic beta-cells through proteolytic cleavage of its prohormone. Both amylin and its precursor can aggregate and produce toxic oligomers and fibrils leading to cell death in the pancreas that can eventually contribute to the development of type 2 diabetes mellitus. The inhibitory effect of the copper(II) ion on amylin aggregation has been recently discovered, but details of the interaction remain unknown. Finding other more physiologically tolerated approaches requires large scale screening of potential inhibitors. Here, we demonstrate that LAESI-IMS-MS can reveal the binding stoichiometry, copper oxidation state, and the dissociation constant of human amylin–copper(II) complex. The conformations of hIAPP in the presence of copper(II) ions were also analyzed by IMS, and preferential association between the β-hairpin amylin monomer and the metal ion was found. The copper(II) ion exhibited strong association with the –HSSNN– residues of the amylin. In the absence of copper(II), amylin dimers were detected with collision cross sections consistent with monomers of β-hairpin conformation. When copper(II) was present in the solution, no dimers were detected. Thus, the copper(II) ions disrupt the association pathway to the formation of β-sheet rich amylin fibrils. Using LAESI-IMS-MS for the assessment of amylin–copper(II) interactions demonstrates the utility of this technique for the high-throughput screening of potential inhibitors of amylin oligomerization and fibril formation. More generally, this rapid technique opens the door for high-throughput screening of potential inhibitors of amyloid protein aggregation.

Introduction: Telemedicine has rapidly become an essential part of primary care due to the COVID-19 pandemic. However, formal training in telemedicine during residency is lacking. We developed and implemented a telemedicine curriculum for a family medicine residency program and investigated its effect on resident confidence levels in practicing telemedicine. Methods: We designed a process map of the telemedicine visit workflow at the residency clinic to identify key topics to cover in the curriculum. We created a live 50-minute didactic lecture on best practices in telemedicine, along with a quick-reference handout. We distributed pre- and postintervention surveys to current residents (N=24) to assess the effect of the educational intervention on their confidence in practicing telemedicine. Results: Fourteen residents (58% response rate) completed all aspects of the study including both surveys and participation in the educational intervention. Confidence levels in conducting telemedicine visits increased in three of five domains: (1) virtual physical exam (P=.04), (2) visit documentation (P=.03), and (3) virtually staffing with an attending (P=.04). Resident interest in using telemedicine after residency also increased following the educational intervention. Conclusion: Telemedicine requires a unique skill set. Formal education on best practices improves resident confidence levels and interest in practicing telemedicine. Primary care residency programs should incorporate telemedicine training to adequately prepare their graduates for clinical practice.

IntroductionMongolia has the highest liver cancer incidence in the world. Hepatocellular carcinoma is the most prevalent primary liver cancer, and the most common risk factors are hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. Although viral hepatitis occurs mostly in the developing world, migration of people from high prevalence countries contributes to the health outcomes of the United States. Data on Mongolian Americans is limited. The objective of this study was to estimate HBV and HCV infection prevalence among Mongolia-born immigrants living in the Washington, District of Columbia, metropolitan area.MethodsWe tested Mongolia-born immigrants for chronic hepatitis at community-based screening events from 2016 to 2017. Descriptive statistics were generated to describe the screening results. Bivariate analysis was conducted to examine the relationship between hepatitis prevalence and sociodemographic characteristics.ResultsOf 634 participants, most did not speak English primarily, were uninsured, and did not have a regular primary care provider. Eighty-two participants (12.9%) had chronic HBV or HCV infection after accounting for HBV and HCV co-infection. Thirty-nine (6.2%) were chronically infected with HBV, and 233 (36.8%) were susceptible to HBV. Sixty-three (9.9%) participants were positive for HCV exposure, and 45 (7.1%) had confirmed chronic HCV infection. While no sociodemographic characteristics were associated with HBV infection, age and primary spoken language (Mongolian) were significantly associated with HCV exposure.ConclusionForeign-born immigrants such as Mongolian Americans have a high prevalence of chronic viral hepatitis infection. Targeted screening, vaccination, and treatment programs can help decrease immigrant risk for developing hepatocellular carcinoma.