Assessing COVID-19 testing strategies in K-12 schools in underserved populations: Study protocol for a cluster-randomized trial

BACKGROUND: Since March 2020, COVID-19 has disproportionately impacted communities of color within the United States. As schools have shifted from virtual to in-person learning, continual guidance is necessary to understand appropriate interventions to prevent SARS-CoV-2 transmission. Weekly testing of students and staff for SARS-CoV-2 within K-12 school setting could provide an additional barrier to school-based transmission, especially within schools unable to implement additional mitigation strategies and/or are in areas of high transmission. This study seeks to understand the role that weekly SARS-CoV-2 testing could play in K-12 schools. In addition, through qualitative interviews and listening sessions, this research hopes to understand community concerns and barriers regarding COVID-19 testing, COVID-19 vaccine, and return to school during the COVID-19 pandemic. METHODS/DESIGN: Sixteen middle and high schools from five school districts have been randomized into one of the following categories: (1) Weekly screening + symptomatic testing or (2) Symptomatic testing only. The primary outcome for this study will be the average of the secondary attack rate of school-based transmission per case. School-based transmission will also be assessed through qualitative contact interviews with positive contacts identified by the school contact tracers. Lastly, new total numbers of weekly cases and contacts within a school-based quarantine will provide guidance on transmission rates. Qualitative focus groups and interviews have been conducted to provide additional understanding to the acceptance of the intervention and barriers faced by the community regarding SARS-CoV-2 testing and vaccination. DISCUSSION: This study will provide greater understanding of the benefit that weekly screening testing can provide in reducing SARS-CoV-2 transmission within K-12 schools. Close collaboration with community partners and school districts will be necessary for the success of this and similar studies. TRIAL REGISTRATION: NCT04875520 . Registered May 6, 2021

Environmental Light and Delirium in the Intensive Care Unit...Presented at the AACN National Teaching Institute in Houston, Texas, May 22-25, 2017.

Purpose: To compare levels of environmental light during the first 24 to 72 hours of intensive care unit (ICU) admission between 2 groups of critically ill adult patients (group 1: patients in whom delirium developed; group 2: patient who remained delirium free). We expected that the delirium-free group would have experienced higher levels of light during the day and lower levels of light at night than the group with delirium. Background: Delirium in adult patients in the ICU is common and is associated with increased complications, mortality, length of stay, and long-term cognitive effects. Poor sleep quality and sleep disturbances have been associated with ICU delirium. Critical care activities and anomalous diurnal variations in light levels may contribute to sleep disturbances. Understanding the effects of environmental light levels on delirium is critical to developing effective prevention and treatment strategies. Method: A retrospective descriptive design was used to compare levels of environmental light (which were not set or adjusted by the researchers) during the first 3 days of ICU stay in 9 patients (4 with delirium and 5 without). The sample was drawn from the control group of a randomized, controlled pilot study of an ICU delirium intervention. Delirium was evaluated by the Confusion Assessment Method--modified ICU version. Environmental light levels at the bedside were recorded continuously from wrist actigraphy monitors. Descriptive statistics, means, and standard deviations were calculated. White-light measures for each group were analyzed at 4 times (6 am, 12 noon, 6 pm, and 12 midnight). Results: Surprisingly, in this small sample, we found higher daytime and lower nighttime light levels in the delirium group. Increased light levels in the ICU room may indicate increased critical care provider activity or increased agitation and reflect underlying increased risk for delirium. Lower light levels may be related to increased sedation. Additional study of factors affecting levels of environmental light and their relationship to delirium is needed

Quantized adhesion detected with the atomic force microscope

The atomic force microscope (AFM) is rapidly becoming a powerful tool for investigating surface chemistry and adhesion. Current efforts with this new instrument are guided by the pioneering research of Israelachvili and his colleagues, whose work with the surface force apparatus has laid the foundation for investigating interactions near and between surfaces. The AFM is capable of measuring forces of less than 10^(-11) N with high spatial resolution, thus making possible the study of very weak interactions and local surface chemistry. Here we report the first (to our knowledge) observation of discrete adhesive interactions with measured forces of 1 x 10^(-11) N. Two mechanisms for this effect are proposed: individual hydrogen bonds between the tip and surface are resolved or ordered water layers create different force minima near the surface

Quantized adhesion detected with the atomic force microscope

The atomic force microscope (AFM) is rapidly becoming a powerful tool for investigating surface chemistry and adhesion. Current efforts with this new instrument are guided by the pioneering research of Israelachvili and his colleagues, whose work with the surface force apparatus has laid the foundation for investigating interactions near and between surfaces. The AFM is capable of measuring forces of less than 10^(-11) N with high spatial resolution, thus making possible the study of very weak interactions and local surface chemistry. Here we report the first (to our knowledge) observation of discrete adhesive interactions with measured forces of 1 x 10^(-11) N. Two mechanisms for this effect are proposed: individual hydrogen bonds between the tip and surface are resolved or ordered water layers create different force minima near the surface

Pseudomonas aeruginosa exotoxin Y-mediated tau hyperphosphorylation impairs microtubule assembly in pulmonary microvascular endothelial cells.

Pseudomonas aeruginosa uses a type III secretion system to introduce the adenylyl and guanylyl cyclase exotoxin Y (ExoY) into the cytoplasm of endothelial cells. ExoY induces Tau hyperphosphorylation and insolubility, microtubule breakdown, barrier disruption and edema, although the mechanism(s) responsible for microtubule breakdown remain poorly understood. Here we investigated both microtubule behavior and centrosome activity to test the hypothesis that ExoY disrupts microtubule dynamics. Fluorescence microscopy determined that infected pulmonary microvascular endothelial cells contained fewer microtubules than control cells, and further studies demonstrated that the microtubule-associated protein Tau was hyperphosphorylated following infection and dissociated from microtubules. Disassembly/reassembly studies determined that microtubule assembly was disrupted in infected cells, with no detectable effects on either microtubule disassembly or microtubule nucleation by centrosomes. This effect of ExoY on microtubules was abolished when the cAMP-dependent kinase phosphorylation site (Ser-214) on Tau was mutated to a non-phosphorylatable form. These studies identify Tau in microvascular endothelial cells as the target of ExoY in control of microtubule architecture following pulmonary infection by Pseudomonas aeruginosa and demonstrate that phosphorylation of tau following infection decreases microtubule assembly

Phosphorylation of tau is essential for disrupted microtubule assembly.

<p>Over-expression of a non-phosphorylatable form of Tau (S214A mutant) rescues PMVECs from effects of ExoY⁺ on microtubule assembly. PMVECs were stably transfected with a cDNA encoding a form of Tau mutated at the PKA phosphorylation site and then infected with <i>P. aeruginosa</i> encoding either ExoY^K81M or ExoY⁺. Microtubules were disassembled by incubation on ice, and then microtubule re-assembly was initiated by transferring cells to 37°C. [<b>A.</b>] S214A Tau-expressing control cells (Ctr) and cells infected with either ExoY^K81M or ExoY⁺ were fixed and labeled with antitubulin antibodies either at the time of transfer to 37°C (top) or at 8 minutes post-transfer (bottom). Bar = 10 µm. [<b>B.</b>] Polymerized (P) and soluble unpolymerized (S) tubulin levels were quantified in S214A-expressing cells at 8 minutes post-transfer to 37°C. Extracts were prepared from control cells (Ctr) and from cells infected with <i>P. aeruginosa</i> expressing either ExoY^K81M or ExoY⁺. There was no significant difference in the ratio of microtubule polymer to soluble tubulin when cells infected with bacteria expressing ExoY⁺ were compared to those expressing ExoY^K81M or uninfected control cells [0.35±0.8 <i>vs.</i> 0.38±0.06 (K81M) and 0.44±0.11 (Ctr); n = 5].</p

ExoY activity causes a decrease in microtubules in PMVECs.

<p>[<b>A</b>] PMVECs infected with <i>P.aeruginosa</i> expressing either non-functional K81M mutant ExoY (ExoY^K81M; center) or wild type ExoY (right) were observed following processing for anti-tubulin immunofluorescence microscopy. Uninfected cells are also shown (left). Bar = 10 µm. [<b>B</b>] Levels of polymerized tubulin (P) and unpolymerized soluble tubulin (S) were quantified by immunoblot analysis using antibody against α-tubulin. Extracts obtained from untreated cells (Ctr) and from PMVECs infected with <i>P. aeruginosa</i> expressing either ExoY^K81M or ExoY⁺ are shown. The ratio of polymerized tubulin to soluble tubulin was significantly less in cells containing wild type ExoY⁺ [0.29±0.06 <i>vs.</i> 0.44±0.05 (ExoY^K81M) and 0.49±0.08 (Ctr); n = 5; P<0.05 compared to both ExoY^K81M and untreated control].</p

ExoY activity does not noticeably affect microtubule assembly from PMVEC centrosomes.

<p>PMVECs were infected with <i>P. aeruginosa</i> expressing either ExoY^K81M (middle panel) or ExoY⁺ (left panel). Untreated cells (Ctr) and infected cells were extracted to remove soluble proteins and then purified rat brain tubulin was added and microtubule nucleation was initiated by incubating at 37°C for 15 min. The preparations then were fixed and labeled with antitubulin antibodies. Centrosome nucleation of microtubules is shown by arrows. Bar = 10 µm.</p

ExoY activity does not noticeably affect microtubule disassembly.

<p>PMVECs were infected with <i>P. aeruginosa</i> expressing either ExoY^K81M (upper panels) or wild type ExoY (middle panels). Following infection, cells were either fixed before microtubule disassembly was induced (left) or at 1 (middle) or 2 minutes (right) after being placed at 0°C. As shown, disassembly was complete in both control (Ctr), ExoY^K81M and ExoY⁺ expressing cells by 2 minutes after transfer to 0°C. Bar = 10 µm.</p