Structural insight into SARS-CoV-2 neutralizing antibodies and modulation of syncytia.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is initiated by binding of the viral Spike protein to host receptor angiotensin-converting enzyme 2 (ACE2), followed by fusion of viral and host membranes. Although antibodies that block this interaction are in emergency use as early coronavirus disease 2019 (COVID-19) therapies, the precise determinants of neutralization potency remain unknown. We discovered a series of antibodies that potently block ACE2 binding but exhibit divergent neutralization efficacy against the live virus. Strikingly, these neutralizing antibodies can inhibit or enhance Spike-mediated membrane fusion and formation of syncytia, which are associated with chronic tissue damage in individuals with COVID-19. As revealed by cryoelectron microscopy, multiple structures of Spike-antibody complexes have distinct binding modes that not only block ACE2 binding but also alter the Spike protein conformational cycle triggered by ACE2 binding. We show that stabilization of different Spike conformations leads to modulation of Spike-mediated membrane fusion with profound implications for COVID-19 pathology and immunity.

Assessment of the relationship between the MLST genetic diversity of Listeria monocytogenes and growth under selective and non-selective conditions.

Listeria monocytogenes can grow under stressful conditions and contaminate various food categories. Progresss in DNA sequencing-based identification methods, such as multi-locus sequence typing (MLST) now allow for more accurate characterization of pathogens. L. monocytogenes MLST genetic diversity is reflected by the different prevalence of the "clonal complexes" (CCs) in foods or infections. Better understanding of the growth potentials of L. monocytogenes is essential for quantitative risk assessment and efficient detection across CCs genetic diversity. Using optical density measurements taken with an automated spectrophotometer, we compared the maximal growth rate and lag phase of 39 strains from 13 different CCs and various food origins, in 3 broths mimicking stresful food conditions (8 °C, aw 0.95 and pH5) and in ISO Standard enrichment broths (Half Fraser and Fraser). This is important as growth could influence risk through pathogen multiplication in food. Besides, enrichment problems could lead to a lack of detection of some CCs. Despite small differences highlighting natural intraspecific variability, our results show that growth performances of L. monocytogenes strains under the conditions tested in selective and non-selective broth do not appear to be strongly correlated to CCs and cannot explain higher CC "virulence" or prevalence.

Enhancing Antigen Cross-Presentation in Human Monocyte-Derived Dendritic Cells by Recruiting the Intracellular Fc Receptor TRIM21.

Suboptimal immune responses to pathogens contribute to chronic infections. One way to improve immune responses is to boost Ag presentation. In this study, we investigate the potential of the tripartite motif-containing 21 (TRIM21) pathway. TRIM21 is a ubiquitously expressed cytosolic protein that recognizes the Fc region of Abs. When Abs that are bound to pathogens enter the cell as immune complexes, binding of TRIM21 to Fc initiates downstream inflammatory signaling and targets the immune complexes for proteasomal degradation. In APCs, peptides generated by proteasomes are loaded onto MHC class I molecules to stimulate CD8 T cell responses, which are crucial for effective immunity to pathogens. We hypothesized that increasing the affinity between immune complexes and TRIM21 might markedly improve CD8 T cell responses to Ags processed by the TRIM21 pathway. Using phage display technology, we engineered the human IgG1 Fc to increase its affinity for TRIM21 by 100-fold. Adenovirus immune complexes with the engineered Fc induced greater maturation of human dendritic cells (DC) than immune complexes with unmodified Fc and stimulated increased Ag-specific CD8 T cell proliferation and IFN-γ release in cocultures of DC-PBMC. Thus, by increasing the affinity between Fc and TRIM21, Ags from immune complexes undergo enhanced cross-presentation on DC, leading to greater CD8 T cell responses. Our study reveals an approach that could potentially be used in vaccines to increase cytotoxic T cell responses against Ags that are targeted or delivered by Fc-modified Abs.

Drug-induced liver injury associated with Complementary and Alternative Medicine: a review of adverse event reports in an Asian community from 2009 to 2014.

BACKGROUND: The use of Complementary and Alternative Medicine (CAM) has been increasing over the years. A recent review of adverse event reports (AERs) associated with CAM in Singapore found a notable number of AERs submitted. The objectives of this study are to analyse hepatotoxicity cases associated with CAM in Singapore based on spontaneous adverse event reporting to the Health Sciences Authority (HSA), and to highlight safety signals for specific herbal ingredients. METHODS: AERs associated with CAM and hepatotoxicity submitted to the Vigilance and Compliance Branch (VCB) of the HSA from 2009 to 2014 were compiled. The following information was extracted and analysed: Demographic information; time to onset; hospitalisation status; outcome; type of hepatotoxicity; ingredients of CAM, and the total daily doses (TDD); concurrent western medicines and health supplements; and reporter details. RESULTS: Fifty-seven reports were eligible for analysis. Thirty-five (61.4 %) cases involved Traditional Chinese Medicine (TCM). The Roussel Uclaf Causality Assessment Method was applied in 29 (82.9 %) of these cases, and the median score was 4 (range: 1-8). Chai Hu (Radix bupleuri) was suspected in 11 (31.4 %) cases. TDDs of most ingredients were within recommended doses of the Chinese Pharmacopoeia. CONCLUSIONS: Drug-induced liver injury is still poorly understood and more objective assessments are warranted. Reporting of adverse events should be strongly advocated to facilitate future analyses and the understanding of risk-benefit profiles of CAM.

An updated analysis on myocarditis and pericarditis cases reported following mRNA SARS-CoV-2 vaccination in Singapore.

INTRODUCTION: Messenger ribonucleic acid (mRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been associated with myocarditis/pericarditis, especially in young males. We evaluated the risk of myocarditis/pericarditis following mRNA vaccines by brand, age, sex and dose number in Singapore. METHODS: Adverse event reports of myocarditis/pericarditis following mRNA vaccines received by the Health Sciences Authority from 30 December 2020 to 25 July 2022 were included, with a data lock on 30 September 2022. Case adjudication was done by an independent panel of cardiologists using the US Centers for Disease Control and Prevention case definition. Reporting rates were compared with expected rates using historical data from 2018 to 2020. RESULTS: Of the 152 adjudicated cases, males comprised 75.0%. The median age was 30 years. Most cases occurred after Dose 2 (49.3%). The median time to onset was 2 days. Reporting rates were highest in males aged 12-17 years for both primary series (11.5 [95% confidence interval [CI] 6.7-18.4] per 100,000 doses, post-Dose 2) and following booster doses (7.1 [95% CI 3.0-13.9] per 100,000 doses). In children aged 5-11 years, myocarditis remained very rare (0.2 per 100,000 doses). The reporting rates for Booster 1 were generally similar or lower than those for Dose 2. CONCLUSIONS: The risk of myocarditis/pericarditis with mRNA vaccines was highest in adolescent males following Dose 2, and this was higher than historically observed background rates. Most cases were clinically mild. The risk of myocarditis should be weighed against the benefits of receiving an mRNA vaccine, keeping in mind that SARS-CoV-2 infections carry substantial risks of myocarditis/pericarditis, as well as the evolving landscape of the disease.

Money Talks: Pilot Financial Wellness Programs to Promote Positive Financial Planning Behaviors Among Residents.

PROBLEM: Graduate medical education programs and national organizations are becoming more involved in promoting trainee financial wellness. Current literature reports residents have poor financial knowledge, high debt levels, low concern about their finances, and deficits in financial preparedness, but there has been little published on best practices for implementing financial wellness programs for residents or measuring meaningful outcomes of such programs. APPROACH: From June 2017 to 2019, the authors invited 277 internal medicine residents from the Stony Brook University Hospital, Montefiore Medical Center, and Johns Hopkins Bayview Medical Center residency programs to participate in financial wellness programs. Each institution held at least one 90-minute financial planning session; Stony Brook also had biannual financial wellness check-ins. Participants were invited to complete a presession, an immediate postsession, and a year-end survey to assess changes in financial planning behaviors. OUTCOMES: Survey response rates were 49% (135/277) for the presession survey, 47% (130/277) for the immediate postsession survey, and 22% (61/277) for the year-end survey. Ninety-six percent (125/130) found the sessions helpful and 98% (120/123) recommended continuing the program in the future. At year-end, the most frequent completed financial planning actions prompted by the session included saving emergency funds, creating a monthly budget, consolidating loans via the Public Service Loan Forgiveness program, contributing to retirement savings, and participating in an employer's retirement plan. Residents liked that some sessions were during intern orientation before the selection of retirement plans. Postgraduate year (PGY) 1 residents were more likely to complete positive financial planning actions and to agree or strongly agree that the session prompted them to take financial planning actions than PGY-2 and PGY-3 residents. NEXT STEPS: While financial wellness programs are well received by internal medicine residents, more robust evidence is needed on curricular delivery methods and program features that promote positive financial planning behaviors.

2D-Material-integrated hydrogels as multifunctional protective skins for soft robots.

Soft robots provide compliant object-machine interactions, but they exhibit insufficient material stability, which restricts them from working in harsh environments. Herein, we developed a class of soft robotic skins based on two-dimensional materials (2DMs) and gelatin hydrogels, featuring skin-like multifunctionality (stretchability, thermoregulation, threat protection, and strain sensing). The 2DM-integrated hydrogel (2DM/H) skins enabled soft robots to execute designated missions in the presence of high levels of heat and various environmental threats while maintaining mild machine temperatures. Via adopting different 2DMs (graphene oxide (GO), montmorillonite (MMT), and titanium carbide (MXene)), the 2DM/H-protected robots were able to perform soft grasping in organic liquids (GO/H) and open fire (MMT/H), and in the presence of electromagnetic radiation and biocontamination (MXene/H). Through blending MXene nanosheets into gelatin, the MXene-blended hydrogel (M-H) skin became strain sensitive, and a GO/M-H gripper exhibited the high-level integration of skin-mimicking capabilities. Finally, we incorporated 2DM/H skins onto an origami-inspired walker robot and a soft batoid-like robot to execute vision-guided searching in fire and underwater locomotion/navigation in chemical spills.

Using the internet to educate adolescents about osteoporosis: application of a tailored web-education system.

Osteoporosis is a "pediatric disease with geriatric consequences." This article describes the development and pilot testing of an online system to educate high school students grades 9-12 about osteoporosis; an age where positive health changes could have long lasting effects. The intervention goal was to improve knowledge about osteoporosis and intent to adopt healthy bone practices. Online pre- and postintervention surveys evaluated participants' pre- and postintervention osteoporosis knowledge, attitudes, preventive practices, and postintervention intent to change healthy bone practices. Participants completed the Web-based program that provided detailed information about osteoporosis, and healthy bone practices, immediately after completing the pretest and just prior to completing the posttest. Eighty-nine students completed both the pre/posttests and were included in data analysis. Participants ranged in age from 13 to 17 and 75% were Caucasian (n = 65). Based on pre/posttest scores of 9 factual questions, students significantly improved their knowledge (p < .0001) and overall knowledge rating about osteoporosis at posttest (p < .001). Participants changed their perception regarding the disease's seriousness (p < .001), and considered adopting osteoporosis prevention practices. The study shows that an interactive educational Web site is an effective method for increasing awareness and understanding of osteoporosis in high school students.

Using the Jigsaw Teaching Method to Enhance Internal Medicine Residents' Knowledge and Attitudes in Managing Geriatric Women's Health.

Introduction: Although studies surveying internal medicine (IM) residency program directors identify geriatric women's health as an essential curriculum topic, there are limited published women's health curricula for IM residents. Our IM residency program performed a needs assessment, which revealed that the majority of residents were unsatisfied with our current curricula and most were not confident managing geriatric women's health. We developed and assessed a structured curriculum to improve IM residents' knowledge and confidence in addressing geriatric women's health. Methods: This 2-hour interactive workshop used the jigsaw teaching method (a cooperative learning strategy where peers deliver specific content in teams) to teach 84 categorical IM residents of all PGY levels about the diagnosis and management of menopause, osteoporosis, urinary incontinence, and abnormal uterine bleeding. Participants completed a pretest and immediate posttest to assess knowledge and confidence about the targeted topics. We compared baseline and postworkshop responses using chi-square and Wilcoxon signed rank tests. Results: Seventy-four (88%) IM residents completed the pretest, and 62 (74%) completed the posttest. Mean knowledge scores improved from 51% to 69% (p < .0001). Residents who reported feeling somewhat confident or confident in addressing women's health topics increased from 14% to 44% (p < .0001). The majority were satisfied or very satisfied with the workshop (94%) and requested additional women's health education (92%). Discussion: Our results suggest that workshops using the jigsaw teaching method can effectively increase IM resident knowledge and confidence in managing geriatric women's health.

Expanding Telehealth Competencies in Primary Care: A Longitudinal Interdisciplinary Simulation to Train Internal Medicine Residents in Complex Patient Care.

BACKGROUND: Despite increasing use of telehealth, there are limited published curricula training primary care providers in utilizing telehealth to deliver complex interdisciplinary care. OBJECTIVE: To describe and evaluate a telehealth curriculum with a longitudinal objective structured clinical examination (OSCE) to improve internal medicine residents' confidence and skills in coordinating complex interdisciplinary primary care via televisits, electronic consultation, and teleconferencing. METHODS: In 2019, 56 first- and third-year residents participated in a 3-part, 5-week OSCE training them to use telehealth to manage complex primary care. Learners conducted a standardized patient (SP) televisit in session 1, coordinated care via inter-visit e-messaging, and led a simulated interdisciplinary teleconference in session 2. Surveys measured confidence before session 1 (pre), post-session 1 (post-1), and post-session 2 (post-2). SP televisit checklists and investigators' assessment of e-messages evaluated residents' telehealth skills. RESULTS: Response rates were pre 100%, post-1 95% (53 of 56), and post-2 100%. Post-intervention, more residents were "confident/very confident" in adjusting their camera (33%, 95% CI 20-45 vs 85%, 95% CI 75-95, P < .0001), e-messaging (pre 36%, 95% CI 24-49 vs post-2 80%, 95% CI 70-91, P < .0001), and coordinating interdisciplinary care (pre 35%, 95% CI 22-47 vs post-2 84%, 95% CI 74-94, P < .0001). More residents were "likely/very likely" to use telemedicine in the future (pre 56%, 95% CI 43-69, vs post-2 79%, 95% CI 68-89, P = .001). CONCLUSIONS: A longitudinal, interdisciplinary telehealth simulation is feasible and can improve residents' confidence in using telemedicine to provide complex patient care.

Bivalent binding of a fully human IgG to the SARS-CoV-2 spike proteins reveals mechanisms of potent neutralization.

In vitro antibody selection against pathogens from naïve combinatorial libraries can yield various classes of antigen-specific binders that are distinct from those evolved from natural infection1-4. Also, rapid neutralizing antibody discovery can be made possible by a strategy that selects for those interfering with pathogen and host interaction5. Here we report the discovery of antibodies that neutralize SARS-CoV-2, the virus responsible for the COVID-19 pandemic, from a highly diverse naïve human Fab library. Lead antibody 5A6 blocks the receptor binding domain (RBD) of the viral spike from binding to the host receptor angiotensin converting enzyme 2 (ACE2), neutralizes SARS-CoV-2 infection of Vero E6 cells, and reduces viral replication in reconstituted human nasal and bronchial epithelium models. 5A6 has a high occupancy on the viral surface and exerts its neutralization activity via a bivalent binding mode to the tip of two neighbouring RBDs at the ACE2 interaction interface, one in the "up" and the other in the "down" position, explaining its superior neutralization capacity. Furthermore, 5A6 is insensitive to several spike mutations identified in clinical isolates, including the D614G mutant that has become dominant worldwide. Our results suggest that 5A6 could be an effective prophylactic and therapeutic treatment of COVID-19.

Financial Attitudes and Behaviors of Internal Medicine and Internal Medicine-Pediatrics Residents.

BACKGROUND: Residents graduate from medical school with increasing levels of debt and also may possess poor financial knowledge and practices. Prior studies have assessed resident financial knowledge and interest in financial education, yet additional information regarding their attitudes about personal finance and financial planning could be essential for the development of relevant curricula. OBJECTIVE: We assessed baseline financial attitudes and planning behaviors of internal medicine and internal medicine-pediatrics residents in 3 geographically diverse academic programs. METHODS: A modified version of the Financial Industry Regulatory Authority National Financial Capability survey was administered anonymously to residents in 3 programs in spring 2017. Outcomes included levels of educational debt, positive financial planning behaviors, perception of finances and debt, and education about personal finance. RESULTS: Response rate was 62% (184 of 298). Rates of educational debt were high, with 81% (149 of 184) of respondents reporting educational debt, and the majority owing more than $100,000. Residents' financial practices were variable, and residents could be grouped into 1 of 3 categories-concerned-engaged, concerned-unengaged, and unconcerned-unengaged-based on their engagement with debt and financial management. Residents with high debt (> $250,000) had a bimodal distribution of respondents who strongly agreed and those who strongly disagreed they were concerned about debt. CONCLUSIONS: Resident financial attitudes and practices are variable, ranging from highly engaged residents actively managing their financial wellness to unengaged residents who have low concern, despite high educational debt.

Candidate salivary biomarkers associated with alveolar bone loss: cross-sectional and in vitro studies.

This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor necrosis factor-alpha, interleukin-6, prostaglandin-E2), and markers of bone turnover [pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), osteocalcin, osteonectin] in stimulated human whole saliva collected from 110 untreated dental patients. Alveolar bone loss scores for each patient were derived from radiographic examination. Variables positively associated with increased bone loss score were: age, current smoking, use of bisphosphonate drugs, and salivary interleukin-1beta levels above the median. Salivary osteonectin levels above the median were associated with a decreased bone loss score. Additional in vitro studies were carried out to determine the fate of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha added to whole and parotid saliva. All cytokines added to saliva were detected in significantly lower concentrations than when added to buffer alone. Protease inhibitors added to saliva did not prevent the reduction in detection of biomarkers. Variation in time of incubation, repeated cycles of freezing and thawing, or exposure to dimethylsulfoxide did not appreciably affect the measurement of cytokines in saliva. These results suggest that detection of biomarkers by conventional immunoassays may underestimate the actual quantity of molecules in saliva.

Impact of environmental factors on the culturability and viability of Listeria monocytogenes under conditions encountered in food processing plants.

The ability of Listeria monocytogenes to adhere to and persist on surfaces for months or even years may be responsible for its transmission from contaminated surfaces to food products. Hence the necessity to find effective means to prevent the establishment of L. monocytogenes in food processing environments. The aim of this study was to assess, through a fractional experimental design, the environmental factors that could affect the survival of L. monocytogenes cells on surfaces to thereby prevent the persistence of this pathogen in conditions mimicking those encountered in food processing plants: culture with smoked salmon juice or meat exudate, use of two materials with different hygiene status, biofilm of L. monocytogenes in pure-culture or dual-culture with a Pseudomonas fluorescens strain, application of a drying step after cleaning and disinfection (C&D) and comparison of two strains of L. monocytogenes. Bacterial survival was assessed by culture, qPCR to quantify total cells, and propidium monoazide coupled with qPCR to quantify viable cells and highlight viable but non-culturable (VBNC) cells. Our results showed that failure to apply C&D causes cell persistence on surfaces. Moreover, the sanitation procedure leads only to a loss of culturability and appearance of VBNC populations. However, an additional daily drying step after C&D optimises the effectiveness of these procedures to reduce culturable populations. Our results reinforce the importance to use molecular tools to monitor viable pathogens in food processing plants to avoid underestimating the amounts of cells using only methods based on cell culture.

Chemistry Testing on Plasma Versus Serum Samples in Dialysis Patients: Clinical and Quality Improvement Implications.

Plasma samples collected in tubes containing separator gels have replaced serum samples for most chemistry tests in many hospital and commercial laboratories. Use of plasma samples for blood tests in the dialysis population eliminates delays in sample processing while waiting for clotting to complete, laboratory technical issues associated with fibrin formation, repeat sample collection, and patient care issues caused by delay of results because of incompletely clotted specimens. Additionally, a larger volume of plasma is produced than serum for the same amount of blood collected. Plasma samples are also acceptable for most chemical tests involved in the care of patients with ESRD. This information becomes very important when United States regulatory requirements for ESRD inadvertently limit the type of sample that can be used for government reporting, quality assessment, and value-based payment initiatives. In this narrative, we summarize the renal community experience and how the subsequent resolution of the acceptability of phosphorus levels measured from serum and plasma samples may have significant implications in the country's continued development of a value-based Medicare ESRD Quality Incentive Program.

The antimicrobial properties of C-reactive protein (CRP).

C-reactive protein, CRP, is a predominant pattern-recognition receptor (PRR) in the plasma of the horseshoe crab, which recognizes lipopolysaccharide (LPS). Native CRP2 has previously been shown to exhibit agglutination activity against the polysialic capsule of Escherichia coli K1 but its role in bacterial clearance is not well characterized. In this work, the antimicrobial activity of a recombinant CRP2 isoform (rCRP2) was tested against E. coli, Pseudomonas aeruginosa and Staphylococcus aureus. rCRP2 agglutinates bacteria and exhibits bactericidal activity against Gram-negative bacteria. In addition, the antimicrobial activity of rCRP2 is calcium-independent. GST pulldown experiments suggest that in the naïve physiological state, CRP2 interacts with hemocyanin, native CRPs, a 35-kDa plasma lectin and an as yet unidentified 40-kDa protein. This interaction was enhanced upon Pseudomonas infection. We propose that rCRP2 is a PRR with potent antimicrobial activity and its interacting partners contribute to effective bacterial clearance.

C-reactive protein: a predominant LPS-binding acute phase protein responsive to Pseudomonas infection.

As a structural component of the outer membrane of Gram-negative bacteria, endotoxin, also known as lipopolysaccharide (LPS) exhibits strong immunostimulatory properties, rendering it a pivotal role in the pathogenesis of Gram-negative septicaemia. Our attempt to identify LPS-binding proteins from the hemolymph of the horseshoe crab led to the isolation and identification of Creactive protein (CRP) as the predominant LPS-recognition protein during Pseudomonas infection. CRP is an evolutionarily ancient member of a superfamily of 'pentraxins'. It is a major protein in acute phase of infection in humans. Our investigation of CRP response to Pseudomonas aeruginosa unveiled a robust innate immune system in the horseshoe crab, which displays rapid suppression of a dosage of 10(6) CFU of bacteria in the first hour of infection and effected complete clearance of the pathogen by 3 days. Such a high dose would have been lethal to mice. Full-length CRP cDNA was cloned. Analysis of the untranslated regions suggests their crucial role in post-transcriptional regulation of CRP transcript levels. Northern blot analysis demonstrated an acute up-regulation of CRP by about 60-fold in 6-48 h of Pseudomonas infection. Taken together, our results provide new insights into the importance of CRP as a conserved molecule for pathogen recognition.