Surface enhanced Raman spectroscopy based analysis of SARS-CoV-2 spike protein binding to ACE2 receptor

The SARS-CoV-2 virus is still a challenge because of its diversity and mutations. The binding interactions of the angiotensin converting enzyme 2 (ACE2) receptor and the spike protein are relevant for the SARS-CoV-2 virus to enter the cell. Consequently, it is important and helpful to analyze binding activities and the changes in the structure of the ACE2 receptor and the spike protein. Surface enhanced Raman spectroscopy is able to analyze small concentrations of the proteins without contact, non-invasively and label-free. In this work, we present a SERS based approach in the visible wavelength range to analyze and study the binding interactions of the ACE2 receptor and the spike protein. SERS measurements of the ACE2 receptor, the spike protein and the ACE2-spike complex were performed. Additionally, an inhibitor was used to prevent the spike protein from binding to ACE2 and to compare the results. The analysis of the measured SERS spectra reveals structural differences and changes due to binding activities. Thus, we show that the performed SERS based approach can help for rapid and non-invasive analysis of binding interactions of the ACE2-spike complex and also of protein binding in general. © 2023 SPIE.

Flow and Pressure Differential Results of a Novel Low-Cost Portable Negative Pressure Patient Enclosure For COVID-19

Study Objectives: To overcome the shortage of negative pressure isolation rooms during the 2019 novel coronavirus pandemic, the novel Covering for Operations during Viral Emergency Response (COVER) device was developed. The main goal of the device is to generate a portable negative pressure environment using non-medical supplies to improve patient and health care worker safety. Several variations of the device were created and tested for their ability to generate the -2.5 pascal (Pa) pressure recommended by the Centers for Disease Control [1]. Methods: Device Construction The device utilizes a rigid, polyvinyl chloride (PVC)-based frame covered in a transparent plastic sheet with a connected sound-isolated vacuum (Figure 1). Access to the patient can occur from either customizable user-made perforations along guidelines marked on the top and sides of the transparent sheet or from along the sheet’s bottom edge. To generate airflow and create a negative pressure environment, the use of either two 10-inch portable fans or various vacuums (Dyson® 1.6 hp, Shop-Vac® 2.5 hp, and Shop-Vac® 3.5 hp) were tested. These airflow-generating fans or vacuums were attached to the device’s two HEPA filter boxes either directly in the case of the fans or using standard 2.75-inch tubing. Airflow and Pressure Differential Testing To assess for device efficacy, we tested the airflow generated by the device using either the fans or the various vacuums. The airflow was tested using a TSI-ALNOR EBT-731 (TSI Incorporated, Shoreview, Minnesota) capture hood and reported in cubic feet per minute (cfm). A PPM3-S Abatement Portable Differential Pressure Monitor (Abatement Technologies, Fort Erie, Canada) was used to record pressure differentials in pascals in real time within the device using each of the vacuums. The device’s pressure differential was measured with a simulated patient present and with and without the maximum 60 cm of functional access cuts made into the device. Results: The airflow measurements are displayed in Table 1. The fans as part of the fully constructed device did not generate any measurable airflow and were dropped from subsequent testing. The highest measured airflow rates and pressure differentials were observed with the 3.5 hp vacuum. All the vacuums generated an observable negative pressure environment even with a simulated patient and 60 cm of access cuts made into the device as shown in Table 2. Conclusion: The COVER device uses off-the-shelf, non-medical components to generate a negative pressure environment using a simulated patient and an aggregate of 60cm of patient care access cuts. [Formula presented] [Formula presented]

Surgical site infections: guidance for elective surgery during the SARS-CoV-2 pandemic - international recommendations and clinical experience.

BACKGROUND: The COVID-19 pandemic not only had an impact on public life and healthcare facilities in general, but also affected established surgical workflows for elective procedures. The strategy to protect patients and healthcare workers from infection by SARS-CoV-2 in surgical departments has needed step-by-step development. Based on the evaluation of international recommendations and guidelines, as well as personal experiences in a clinical 'hot spot' and in a 450-bed surgical clinic, an adapted surgical site infection (SSI) prevention checklist was needed to develop concise instructions, which described roles and responsibilities of healthcare professionals that could be used for wider guidance in pandemic conditions. METHOD: Publications of COVID-19-related recommendations and guidelines, produced by health authorities and organizations, such as WHO, US-CDC, ECDC, the American College of Surgery and the Robert Koch Institute, were retrieved, assessed and referenced up to 31st January 2020. Additionally, clinical personal experiences in Germany were evaluated and considered. RESULTS: Part 1 of this guidance summarizes the experience of a tertiary care, surgical centre which utilized redundant hospital buildings for immediate spatial separation in a 'hot spot' COVID-19 area. Part 2 outlines the successful screening and isolation strategy in a surgical clinic in a region of Germany with outbreaks in surrounding medical centres. Part 3 provides the synopsis of personal experiences and international recommendations suggested for implementation during the COVID-19 pandemic. CONCLUSION: Understanding of COVID-19, and SARS-CoV-2-related epidemiology, is constantly and rapidly changing, requiring continuous adaptation and re-evaluation of recommendations. Established national and local guidelines for continuation of surgical services and prevention of SSI require ongoing scrutiny and focused implementation. This manuscript presents a core facility checklist to support medical institutions to continue their clinical and surgical work during the COVID-19 pandemic.

[Prioritization of intensive medical treatment places - Concept proposal]. / Priorisierung intensivmedizinischer Behandlungsplätze ­ Konzeptvorschlag.

In the situation of a shortage of ventilation beds, ethically justifiable, transparent and comprehensible decisions must be made. This concept proposes that all patients are first intubated depending on necessity and then assessed by a triage team afterwards. In this situation newly admitted COVID patients compete with newly admitted Non-COVID patients as well as patients already treated in intensive care units for a ventilator. The combination of short-term and long-term prognoses should enable the interprofessional triage team to make comprehensible decisions. The aim of the prioritization concept is to save as many human lives as possible and to relieve the treatment team of the difficult decision on prioritization.