Advancements in Rapid and Affordable Diagnostic Testing for Respiratory Infectious Diseases: Evaluation of Aptamer Beacon Technology for Rapid and Sensitive Detection of SAR-CoV-2 in Breath Condensate.

The demand for rapid and efficient diagnostic point-of-care tests for respiratory infectious diseases has become increasingly critical in the current landscape. The emphasis on accessibility has been underscored over the past year, making it crucial to have biological components that exhibit fast and accurate kinetics. The foundation for precise, swift, and effective testing relies on the availability of highly responsive biological agents. Two published aptamer DNA sequences designated Song and MSA52 and their truncated internal stem-loop structures were studied for their potential to serve as aptamer beacons for rapid COVID detection. The candidate beacons were covalently labeled with Atto 633 dye attached to their 5' ends and Iowa Black quencher attached to their 3' ends. The whole aptamer structures exhibited the greatest fluorescence signal intensities and higher fluorescence background than their truncated internal stem-loop beacon structures suggesting that the distance between fluorophores and quenchers was greater for the whole aptamer beacon candidates versus the isolated stem-loop structures. Beacon candidates were tested against two heat- or gamma radiation-killed SARS-CoV-2 Washington 1/2020 virus samples and three different COVID spike (S) proteins to test their effectiveness. Despite the higher background fluorescence, the whole aptamer beacons showed better signal-to-noise ratios and were selected for further investigation. Limit of detection (LOD) studies revealed that both the whole Song and whole MSA52 aptamer beacon candidates had a LOD of 9.61 × 103 genome equivalents in phosphate-buffered saline using the red channel of a Promega Quantus™ fluorometer which correlated well with confirmatory spectrofluorometry. Cross-reactivity studies using numerous COVID variants, related coronaviruses, and other common respiratory pathogens suggested greater COVID selectivity for the whole MSA52 versus the whole Song aptamer beacon candidate, indicating promise for specific COVID detection. Importantly, both whole aptamer beacon candidates exhibited very rapid "bind and detect" fluorescence increases within the first 1-2 min of mixing the beacons with killed SARS-CoV-2 viruses in 100 µl samples. Overall, this work illustrates the strong potential for aptamer beacons for rapid, on-site detection and presumptive diagnosis of COVID in breath condensates or other small liquid samples. This research highlights the strong potential of aptamer beacons for addressing the need for fast and convenient diagnostic tools in global health contexts, especially in resource-limited settings.

Telemedicine Physical Examination Utilizing a Consumer Device Demonstrates Poor Concordance with In-Person Physical Examination in Emergency Department Patients with Sore Throat: A Prospective Blinded Study.

BACKGROUND: Telemedicine allows patients to connect with healthcare providers remotely. It has recently expanded to evaluate low-acuity illnesses such as pharyngitis by using patients' personal communication devices. The purpose of our study was to compare the telemedicine-facilitated physical examination with an in-person examination in emergency department (ED) patients with sore throat. MATERIALS AND METHODS: This was a prospective, observational, blinded diagnostic concordance study of patients being seen for sore throat in a 60,000-visit Midwestern academic ED. A telemedicine and a face-to-face examination were performed independently by two advanced practice providers (APP), blinded to the results of the other evaluator. The primary outcome was agreement on pharyngeal redness between the evaluators, with secondary outcomes of agreement and inter-rater reliability on 14 other aspects of the pharyngeal physical examination. We also conducted a survey of patients and providers to evaluate perceptions and preferences for sore throat evaluation using telemedicine. RESULTS: Sixty-two patients were enrolled, with a median tonsil size of 1.0. Inter-rater agreement (kappa) for tonsil size was 0.394, which was worse than our predetermined concordance threshold. Other kappa values ranged from 0 to 0.434, and telemedicine was best for detecting abnormal coloration of the palate and tender superficial cervical lymph nodes (anterior structures), but poor for detecting abnormal submandibular lymph nodes or asymmetry of the posterior pharynx (posterior structures). In survey responses, telemedicine was judged easier to use and more comfortable for providers than patients; however, neither patients nor providers preferred in-person to telemedicine evaluation. CONCLUSION: Telemedicine exhibited poor agreement with the in-person physical examination on the primary outcome of tonsil size, but exhibited moderate agreement on coloration of the palate and cervical lymphadenopathy. Future work should better characterize the importance of the physical examination in treatment decisions for patients with sore throat and the use of telemedicine in avoiding in-person healthcare visits.

Semaphorin 7A is expressed on airway eosinophils and upregulated by IL-5 family cytokines.

Semaphorin 7A (sema7a) plays a major role in TGF-ß1-induced lung fibrosis. Based on the accumulating evidence that eosinophils contribute to fibrosis/remodeling in the airway, we hypothesized that airway eosinophils may be a significant source of sema7a. In vivo, sema7a was expressed on the surface of circulating eosinophils and upregulated on bronchoalveolar lavage eosinophils obtained after segmental bronchoprovocation with allergen. Based on mRNA levels in unfractionated and isolated bronchoalveolar cells, eosinophils are the predominant source of sema7a. In vitro, among the members of the IL-5-family cytokines, sema7a protein on the surface of blood eosinophils was increased more by IL-3 than by GM-CSF or IL-5. Cytokine-induced expression of cell surface sema7a required translation of newly synthesized protein. Finally, a recombinant sema7a induced alpha-smooth muscle actin production in human bronchial fibroblasts. semaphorin 7A is a potentially important modulator of eosinophil profibrotic functions in the airway remodeling of patients with chronic asthma.