Enhancing Notification Awareness for Online Presenters via a Wrist-Worn Device

The practice of giving presentations online has exploded during the Covid pandemic. However, in these settings, presenters often find themselves overlooking questions and feedback, e.g. via chat, from the audience, because the presenter's screen is dominated by their slides, with other channels becoming less noticeable. This causes frustration among presenters and their audience alike. We investigate the impact of additional visual, auditory, and haptic cues for presenters in online scenarios, using a wrist-worn prototype. For this, we conducted a study where participants gave presentations via the videoconferencing tool Zoom on specific topics while trying to notice and correctly identify incoming notifications. Our findings indicate that supplementary notifications can be helpful in online presentations without inappropriately disturbing the presenter. © 2023 Owner/Author.

Immunoglobulin Class Profiles of ABO Antibodies in Saliva and Serum of Healthy Individuals

Introduction: The coronavirus disease (COVID-19) pandemic gave rise to studies investigating the association of ABO blood group with COVID-19 susceptibility. It is hypothesized that ABO antibodies might play a role in neutralizing SARS-CoV-2. However, ABO antibodies were exclusively analyzed in blood samples. Investigation of ABO antibodies in saliva, an easy-to-obtain surrogate for respiratory secretions, may provide novel insights into mucosal immunity crucial in early defense against respiratory pathogens. Methods: In this study, saliva and serum samples from healthy individuals with known blood groups were investigated using a flow cytometric method for separate anti-A/anti-B IgA, IgM, and IgG class antibody detection. Saliva samples were additionally tested using hemagglutination-based neutral and indirect anti-human globulin test gel cards. This method comparison was complemented by dilution experiments with a high-titer anti-A/anti-B WHO standard. Results: In saliva, IgA was the most abundant ABO antibody class, followed by IgM;IgG was detected only in low levels in all non-AB blood types. In serum, IgM was the predominant ABO antibody class in all non-AB blood types, followed by IgA and IgG, the latter mainly detected in group O individuals. Saliva and serum samples of group O individuals yielded the highest variability of ABO-specific antibody levels. Regardless of sample material and blood type, major interindividual differences in ABO antibody reactivities were recorded. Antibody levels correlated moderately between these two body fluids. There were no significant sex and age-group differences in ABO antibody levels in both serum and saliva. WHO standard dilution experiments yielded technique-specific limits of detection, illustrating the inherent differences of immunofluorescence versus agglutination. Conclusion: For the first time, salivary ABO antibodies were investigated by separate detection of the three most relevant antibody classes IgA, IgM, and IgG in a healthy cohort. This study opens new perspectives regarding mucosal ABO antibody class profiles and their potential influence on respiratory infections.

Functional studies on the interaction between anti-PF4 antibodies and anticoagulants in vaccine-induced thrombotic thrombocytopenia

Background: With increasing number of vaccinations against SARS-CoV-2, rare but life threatening thrombotic events at unusual sites have been reported, and collectively this phenomenon is termed as vaccine-induced immune thrombotic thrombocytopenia (VITT). Pathophysiology of VITT is similar to that of heparin-induced thrombocytopenia (HIT), and associated with platelet-activating antibodies against platelet factor 4 (PF4). Aim(s): Current guidelines for anticoagulation in VITT patients are issued accordingly, with a focus on non-heparin anticoagulants. In this study, we investigated the interactions of heparin, danaparoid, fondaparinux and argatroban with VITT-Ab/ PF4 complexes. Method(s): We utilized an in-house enzyme immunoassays (EIA) to estimate antibody binding, inhibition and dissociation of preformed PF4-VITT complexes. Using biolayer interferometry (BLI), we analyzed binding kinetics and dissociation of complexes in real time. In a flow-based ex vivo model, we assessed the impact of anticoagulants on VITT-mediated thrombus formation. Result(s): We found that heparin and danaparoid not only inhibited VITT IgG binding to PF4 but were also able to effectively dissociate preformed PF4/IgG complexes in EIA. In BLI, binding of PF4 specific antibodies was observed for all VITT samples tested, and we found remarkable changes in their dissociation after addition of various anticoagulants. Furthermore, IgGs from VITT patients induce increased thrombus formation in comparison to the healthy controls (mean % SAC +/- SEM: 11.59 +/- 0.57 vs. 1.99 +/- 0.34 respectively, p < 0.001), which can further be effectively inhibited with danaparoid and heparin (mean % SAC +/- SEM 2.82 +/- 0.50 and 1.85 +/- 0.56. p < 0.001). Fondaparinux and argatroban inhibited thrombus formation;however, they did not affect antibody binding. Conclusion(s): Taken together, our data shed a light on suitability of anticoagulants in VITT, and indicate that negatively charged anticoagulants can disrupt VITT-Ab/ PF4 interactions, which might serve as an approach to reduce antibody-mediated complications in VITT. Our results should be confirmed, however, in a clinical setting before a recommendation regarding the selection of anticoagulation in VITT patients could be made.

VIRTUALLY DECIDED: A MIXED-METHODS EXPLORATION OF PATIENT, PROVIDER, AND SYSTEM-LEVEL FACTORS INFLUENCING VA CARDIOLOGISTS' PROVISION OF TELEMEDICINE

BACKGROUND: Virtual cardiology care, defined as care delivered by phone or video, expanded rapidly in the Veterans Health Administration (VA) at the onset of the COVID-19 pandemic and remains a significant proportion of all VA cardiology care. However, factors influencing whether a visit is conducted virtually are poorly understood. METHODS: In this mixed-methods study, we first analyzed a nationwide cohort of Veterans who had a cardiology visit before COVID-19 (1/1/2019-3/ 10/2020), some of whom had follow-up visits before COVID and others afterwards (3/10-2020-3/10/2021). We assessed the hazard of receiving cardiology-related video care and any virtual care with a survival model adjusted for baseline patient sociodemographic and clinical characteristics;we performed analyses with and without adjustment for geographic region via Veterans Integrated Service Network location (VISN). Then, we conducted qualitative interviews with VA cardiologists to further characterize the variation identified in the hazard of video and virtual care utilization. RESULTS: We analyzed 416,621 Veterans;average patient age was 69.1 years and 5.0% were female. Older, low-income, and rural-dwelling Veterans had a lower hazard (i.e. time to event) of using video care (adjusted hazard ratio for ages 75 and older 0.80, 95% CI 0.75-0.86;for low-income status 0.94, 95% CI 0.89-0.98;for highly rural residents 0.77, 95% CI 0.68-0.87). The hazard ratios for a video-based encounter varied across geographic regions, with adjusted hazard ratios for use of video care as low as 0.06 (95% CI 0.04-0.07) compared to the reference region with highest use of video care. In our qualitative assessment, cardiologists (N=7) suggested patient, provider, and system-level factors influencing visit modality. At the patient level, clinicians perceived that older, lower-income, and rural-dwelling Veterans had more difficulty accessing video technology, but also benefited disproportionately from virtual care from the convenience of avoiding travel to a VA facility. At the provider level, clinicians preferred virtual care for routine follow-up visits and visits for conditions when most pertinent information could be collected from history (e.g. stable coronary artery disease). At the system level, clinicians noted explicit and implicit nudges toward certain modalities, such as differential productivity accounting (e.g. video visits counting as more productivity units than phone visits) and praise for high video care users, and differed in their perception of whether the system or clinician primarily drove choice of visit modality. CONCLUSIONS: Likelihood and timing of virtual cardiology care varies across VA patients and sites due to patient, clinician, and system factors. VA cardiologists perceive variability in the degree to which autonomy over visit modality choice lies with providers versus the system. Policies intended to alter visit modality mix should consider these types of influences as well as varying autonomy in modality choice.

Reduced levels of ABO anti-A and anti-B of IGM, IGG and IGA isotypes in the serum but not the saliva of individuals recovered from COVID-19

Background: Recent studies reported that individuals with ABO blood type O are underrepresented among patients infected with severe acute respiratory syndrome coronavirus SARS-CoV-2 compared with controls. Our preceding study results indicated a lower proportion of individuals with blood type O accompanied by a higher incidence of blood type AB in patients hospitalized with COVID-19 than in healthy blood donors. Thus, we hypothesized that the variable susceptibility to infection with SARS-CoV-2 might be related to interference caused by circulating ABO antibodies and further may be influenced by the antibody titers which vary widely between individuals. Aims: Therefore, we aimed to investigate ABO antibody levels, including IgM, IgG and IgA subclasses, in the serum and saliva of Caucasians (n = 187), who recovered from mild COVID-19 and to compare them with those of individuals who had never been infected with the virus. Further, a possible association between ABO antibodies and virusspecific total antibody concentrations in the COVID-19 convalescents as well as a potential relationship between the total IgA secreted in saliva and anti-A/anti-B specific IgA in saliva specimens were addressed. Methods: The convalescent study participants were recruited between June 2020 and February 2021. Individuals who had been hospitalized with COVID-19 or who were pregnant were excluded from the study. Two samples were collected within 2 months after the diagnosis (median days: 44) and approximately 2 months later (median days: 66 days). Isotype specific anti-A and anti-B were determined by flow cytometry on a FACS Canto II. The results were compared with the levels in samples from blood and saliva donors. The antibodies specific to SARS-CoV-2 as well as total IgA in saliva were tested by ELISA. Results: COVID-19 convalescents had significantly lower levels of anti-A and anti-B IgM, IgG and IgA in their serum than control subjects (p < 0.001). ABO antibody levels tested in saliva of participants who previously suffered from COVID-19 did not differ significantly from antibody levels tested in saliva controls (p ≥ 0.338). ABO antibody levels remained stable over the period considered. No significant association between the level of ABO antibodies and SARS-CoV-2-specific antibodies was observed (-0.44 < rho < 0.42, p > 0.053). Total IgA in saliva was lower in convalescents than in controls (p = 0.038). Summary/Conclusions: We observed consistently lower serum concentrations of anti-A and anti-B in COVID-19 convalescents than in healthy controls, suggesting ABO antibodies to conferring a degree of protection against SARS-CoV-2 infection. There may be an increased susceptibility to SARS-CoV-2 infection due to individual preexisting low ABO antibody levels. However, the mechanism underlying our observation of significantly reduced ABO antibodies in the serum, but not in the saliva of affected individuals remains unresolved. Further studies to better understand the molecular mechanism underlying our observation are needed.

COVID-19 rural health inequities: insights from a real-world scenario. (Special Issue: COVID-19 and health inequities: insights from communication research and practice.)

Background: During the pandemic, Mount Pleasant, Texas became a hotspot for Covid-19 cases in the Hispanic community employed by a local meat packing plant and many other industries. An important consideration for rural communities is the language barrier and lack of easily accessible Spanish information explaining Covid-19. In addition, rapidly changing discoveries about the virus and subsequent vaccines creates a sense of confusion within this population already burdened with difficulty understanding health information leading to even more confusion about prevention, treatment and vaccine acceptance.

"On-Chip"-Cryopreservation For Cell-Based Biosensors and Lab-On-A-Chip Systems

There is an increased number of publications on biosensors addressing substances such as pollutants, toxins, or viruses, like SARS-CoV-2. Cell-based biosensors, which use cells as biorecognition elements (bioreceptor), offer outstanding advantages regarding a fast and sensitive detection of these substances. However, there are only a few cell-based biosensors available on the market because such sensor chip contains a ‘living’ component (e.g., adherent mammalian cells), which is very vulnerable and demanding for certain vital parameters (e.g., oxygen, nutrients, pH) as well as temperature during storage and transportation to the end-user. This challenge often hinders the commercialization and practical applicability of cell-based biosensors. There is still an urgent need for preservation tools and methods to enable “off-the-shelf” format as well as ready-to-use on-site systems. Herein, we studied a strategy named “on-sensor cryopreservation (OSC)”, a method for preserving this living component by freezing it (-80 °C) directly on the biosensor surface. However, it is found that cryo-injury on cells occurs over a freeze-thaw cycle, which is most likely due to a mismatch in the coefficient of linear thermal expansion between the frozen cell membrane and the typically rigid sensor surface in contact. Thus, to protect the cells from cryo-injury by absorbing this mismatch energy, the rigid sensor surface was modified with elastic electrospun fibers composed of a polymer (polyethylene vinyl acetate), which has a low glass-transition temperature and a high thermal expansion coefficient. The modified sensor chip is then integrated into a microfluidic system to obtain a so-called cryo-chip. The presented cryo-chip is found to be effective for keeping cells viable during cryopreservation as well as for post-thaw monitoring of extracellular acidification, exemplarily demonstrated for CHO-K1 cells. Cryopreservation of the chips containing cells at the manufacturing stage and transporting them through cold-chain transport can pave the way for “all-in-one” format and “off-the-shelf” applicability. Funding: DÖ would like to acknowledge the Ph.D. research scholarship grant from the Scientific and Technological Research Council of Turkey (TÜBITAK). The authors gratefully thank the Federal Ministry of Education and Research of Germany (Opto-Switch FKZ: 13N12585). Conflict of Interest: None to disclose

Unilateral axillary adenopathy following COVID-19 vaccination: a multimodality pictorial illustration and review of current guidelines.

We present a multimodality pictorial review of axillary lymphadenopathy in patients recently vaccinated against COVID-19. As the mass vaccination programme continues to be rolled out worldwide in an effort to combat the pandemic, it is important that radiologists consider recent COVID-19 vaccination in the differential diagnosis of unilateral axillary lymphadenopathy and are aware of typical appearances across all imaging methods. We review current guidelines on the management of unilateral axillary lymphadenopathy in the context of recent COVID-19 vaccination.

[PIMS-a new pediatric challenge]. / PIMS ­ eine neue pädiatrische Herausforderung: 9-Jahre alter Knabe mit SARS-CoV-2 assoziiertem hyperinflammatorischem Schocksyndrom.

The boy of Egyptian origin was previously healthy. After a history of fever for 7 days, abdominal pain, vomiting and dry cough resistant to treatment with oral antibiotics, he was admitted to hospital. The clinical examination showed a slightly red throat, a tense abdomen and erythema. The blood tests revealed leukocytosis and significantly increased inflammatory parameters. The abdominal ultrasound showed thickened intestinal loops in the left lower abdomen and the echocardiography showed minimal mitral regurgitation, a narrow pericardial effusion lamella over both ventricles and normal coronary arteries. Accordingly, cardiac enzymes were elevated. The day after admission, the boy developed an increasing rash and was transferred to the PICU because of septic shock refractory to high volume resuscitation, requiring hemodynamic support with noradrenaline and noninvasive respiratory assistance. The initial testing for SARS-CoV­2 on nasopharyngeal aspirates was negative twice; however, serum IgG antibodies were positive. Other viral and bacterial infections were excluded as the cause of the symptoms.The patient received IVIG, ASS, furosemide and methylprednisolone and the antibiotic treatment was continued. The dosage of the catecholamine could be reduced according to the patient's condition and the serially performed echocardiographic findings. The patient recovered in his general condition and was discharged from the PICU after 8 days. With the help of a detailed family history, we were able to figure out that the whole family, including the patient himself, had symptoms of a cold about 1 month earlier. Hence, SARS-CoV­2 antibody tests carried out showed a positive result for all of them.Pediatric inflammatory multisystem syndrome (PIMS) can quickly lead to manifest shock symptoms, necessitating close monitoring. A PICU background is crucial to treat possibly occurring symptoms and complications. High-dose steroids are used therapeutically alongside supportive therapies.