Background: The novel coronavirus disease 2019 (COVID-19) pandemic is an urgent public health crisis, with epidemiologic models predicting severe consequences, including high death rates, if the virus is permitted to run its course without any intervention or response. Contact tracing using smartphone technology is a powerful tool that may be employed to limit disease transmission during an epidemic or pandemic; yet, contact tracing apps present significant privacy concerns regarding the collection of personal data such as location. Objective: The aim of this study is to develop an effective contact tracing smartphone app that respects user privacy by not collecting location information or other personal data. Methods: We propose the use of an anonymized graph of interpersonal interactions to conduct a novel form of contact tracing and have developed a proof-of-concept smartphone app that implements this approach. Additionally, we developed a computer simulation model that demonstrates the impact of our proposal on epidemic or pandemic outbreak trajectories across multiple rates of adoption. Results: Our proof-of-concept smartphone app allows users to create “checkpoints” for contact tracing, check their risk level based on their past interactions, and anonymously self-report a positive status to their peer network. Our simulation results suggest that higher adoption rates of such an app may result in a better controlled epidemic or pandemic outbreak. Conclusions: Our proposed smartphone-based contact tracing method presents a novel solution that preserves privacy while demonstrating the potential to suppress an epidemic or pandemic outbreak. This app could potentially be applied to the current COVID-19 pandemic as well as other epidemics or pandemics in the future to achieve a middle ground between drastic isolation measures and unmitigated disease spread.

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It is known that culture media (CM) promotes cellular growth, adhesion, and protects explanted primary brain cells from in vitro stresses. The fetal bovine serum (FBS) supplement used in most CM, however, contains significant quantities of extracellular vesicles (EVs) that confound quantitative and qualitative analyses from the EVs produced by the cultured cells. We quantitatively tested the ability of common FBS EV-depletion protocols to remove exogenous EVs from FBS-supplemented CM and evaluated the influence such methods have on primary astrocyte culture growth and viability. We assessed two methodologies utilized for FBS EV removal prior to adding to CM: (1) an 18-h ultracentrifugation (UC); and (2) a commercial EV-depleted FBS (Exo-FBS™). Our analysis demonstrated that Exo-FBS™ CM provided the largest depletion (75%) of total FBS EVs, while still providing 6.92 × 10⁹ ± 1.39 × 10⁸ EVs/mL. In addition, both UC and Exo-FBS™ CM resulted in poor primary astrocyte cell growth and viability in culture. The two common FBS EV-depletion methods investigated, therefore, not only contaminate in vitro primary cell-derived EV analyses, but also provide a suboptimal environment for primary astrocyte cell growth and viability. It appears likely that future CM optimization, using a serum-free alternative, might be required to advance analyses of cell-specific EVs isolated in vitro.

OBJECTIVE: For symptomatic nonsecreting pituitary adenomas (PAs), resection remains a critical option for treatment. In this study, the authors used a large-population national database to compare endoscopic surgery (ES) to nonendoscopic surgery (NES) for the surgical management of PA. METHODS: The National Cancer Database was queried for all patients diagnosed with histologically confirmed PA who underwent resection between 2010 and 2016 in which the surgical approach was specified. Due to database limitations, microsurgery and craniotomy were both categorized as NES. RESULTS: Of 30,488 identified patients, 16,373 (53.7%) underwent ES and 14,115 (46.3%) underwent NES. There was a significant increase in the use of ES over time (OR 1.16, p < 0.01). Furthermore, there was a significant temporal increase in ES approach for tumors ≥ 2 cm (OR 1.17, p < 0.01). Compared to NES, patients who underwent ES were younger (p = 0.01), were treated at academic centers (p < 0.01), lived a greater distance from their treatment site (p < 0.01), had smaller tumors (p < 0.01), had greater medical comorbidity burden (p = 0.04), had private insurance (p < 0.01), and had a higher household income (p < 0.01). After propensity score matching to control for age, tumor size, Charlson/Deyo score, and type of treatment center, patients who underwent ES had a shorter length of hospital stay (LOS) (3.9 ± 4.9 days vs 4.3 ± 5.4 days, p < 0.01), although rates of gross-total resection (GTR; p = 0.34), adjuvant radiotherapy (p = 0.41), and 90-day mortality (p = 0.45) were similar. On multivariate logistic regression, African American race (OR 0.85, p < 0.01) and tumor size ≥ 2 cm (OR 0.89, p = 0.01) were negative predictors of receiving ES, whereas diagnosis in more recent years (OR 1.16, p < 0.01), greater Charlson/Deyo score (OR 1.10, p = 0.01), receiving treatment at an academic institution (OR 1.67, p < 0.01) or at a treatment site ≥ 20 miles away (OR 1.17, p < 0.01), having private insurance (OR 1.09, p = 0.01), and having a higher household income (OR 1.11, p = 0.01) were predictive of receiving ES. Compared to the ES cohort, patients who started with ES and converted to NES (n = 293) had a higher ratio of nonwhite race (p < 0.01), uninsured insurance status (p < 0.01), longer LOS (p < 0.01), and higher rates of GTR (p = 0.04). CONCLUSIONS: There is an increasing trend toward ES for PA resection including its use for larger tumors. Although ES may result in shorter LOS compared to NES, rates of GTR, need for adjuvant therapy, and short-term mortality may be similar. Factors such as tumor size, insurance status, facility type, income, race, and existing comorbidities may predict receiving ES.