The Spike (S) protein is the main handle for SARS-CoV-2 to enter host cells via surface ACE2 receptors. How ACE2 binding activates proteolysis of S protein is unknown. Here, using amide hydrogen-deuterium exchange mass spectrometry and molecular dynamics simulations, we have mapped the S:ACE2 interaction interface and uncovered long-range allosteric propagation of ACE2 binding to sites necessary for host-mediated proteolysis of S protein, critical for viral host entry. Unexpectedly, ACE2 binding enhances dynamics at a distal S1/S2 cleavage site and flanking protease docking site ~27 Å away while dampening dynamics of the stalk hinge (central helix and heptad repeat) regions ~130 Å away. This highlights that the stalk and proteolysis sites of the S protein are dynamic hotspots in the pre-fusion state. Our findings provide a dynamics map of the S:ACE2 interface in solution and also offer mechanistic insights into how ACE2 binding is allosterically coupled to distal proteolytic processing sites and viral-host membrane fusion. Our findings highlight protease docking sites flanking the S1/S2 cleavage site, fusion peptide and heptad repeat 1 (HR1) as alternate allosteric hotspot targets for potential therapeutic development.

To overcome the problem of in-stent restenosis, the concept of local delivery of antiproliferative or immunosuppressive drugs has been introduced into interventional cardiology. Local drug delivery can be achieved by drug-eluting stents coated with polymer surfaces used for controlled drug release. However, several polymer coatings have shown an induction of inflammatory response and increased neointima formation. In the present study, the effect of a new inorganic ceramic nanoporous aluminum oxide (Al(2)O(3)) coating on neointima proliferation and its suitability as a carrier for the immunosuppressive drug tacrolimus have been investigated. 316 L stainless steel coronary stents were coated with a 500 nm thin nanoporous aluminum oxide layer. This ceramic nanolayer was used as a carrier for tacrolimus. Bare stents (n = 6), ceramic coated stents (n = 6), and ceramic coated stents loaded with 60 (n = 7) and 120 mug (n = 6) tacrolimus were implanted in the common carotid artery of New Zealand rabbits. The ceramic coating caused no significant reduction of neointimal thickness after 28 days. Loading the ceramic stents with tacrolimus led to a significant reduction of neointima thickness by 52% for 60 mug (P = 0.047) and 56% for 120 mug (P = 0.036) as compared to the bare stents. The ceramic coating alone as well as in combination with tacrolimus led to a reduced infiltration of lymphocytes and macrophages in the intima in response to stent implantation. Ceramic coating of coronary stents with a nanoporous layer of aluminum oxide in combination with tacrolimus resulted in a significant reduction in neointima formation and inflammatory response. The synergistic effects of the ceramic coating and tacrolimus suggest that this new approach may have a high potential to translate into clinical benefit.

Lactating women can produce protective antibodies in their milk after vaccination, which has informed antenatal vaccination programs for diseases such as influenza and pertussis. However, whether SARS-CoV-2-specific antibodies are produced in human milk as a result of COVID-19 vaccination is still unclear. In this study, we show that lactating mothers who received the BNT162b2 vaccine secreted SARS-CoV-2-specific IgA and IgG antibodies into milk, with the most significant increase at 3–7 days post-dose 2. Virus-specific IgG titers were stable out to 4–6 weeks after dose 2. In contrast, SARS-CoV-2-specific IgA levels showed substantial decay. Vaccine mRNA was detected in few milk samples (maximum of 2 ng/ml), indicative of minimal transfer. Additionally, infants who consumed post-vaccination human milk had no reported adverse effects up to 28 days post-ingestion. Our results define the safety and efficacy profiles of the vaccine in this demographic and provide initial evidence for protective immunity conferred by milk-borne SARS-CoV-2-specific antibodies. Taken together, our study supports recommendations for uninterrupted breastfeeding subsequent to mRNA vaccination against COVID-19.

Background and Aim Considering the large size of the potential population and limitations of common detection methods, covert hepatic encephalopathy (CHE) is difficult to screen for routinely. The present study aims to explore EncephalApp Stroop Test as a smartphone‐based CHE screening tool in China. Methods A multicenter, single‐visit study was carried out. The cutoff of the Chinese EncephalApp translation was determined by using Chinese standardized psychometric hepatic encephalopathy score (PHES) in cirrhotic patients as the gold standard. Indicators reflecting time required and number of tests on subtask on (naming the color of pound signs) and off (naming the color of the word in discordant coloring) were recorded, with the feedback from investigators and patients. Results One hundred forty‐four patients were included; 58 (40.28%) patients were diagnosed with CHE by PHES. The cutoff of > 97.34 s for off time and > 186.63 s for on time + off time had the maximum area under the curve values (0.77) in all patients. Furthermore, with the cutoff of 186.63 s, on time + off time has the highest sensitivity (0.86). However, the specificity was unsatisfactory (0.59). Age and alcoholic hepatitis (odds ratio = 1.05 and 3.12, both P < 0.05) were positively correlated with the risk of CHE. The experience with electronic devices and education duration were negatively correlated (odds ratio = 0.21 and 0.92, both P < 0.05). Compared with PHES, EncephalApp represented 38% time saving. Furthermore, it was superior to PHES regarding accessibility, convenience, and acceptability by administrators (all P < 0.05). Conclusions The EncephalApp Stroop Test is an efficient screening tool for CHE in Chinese cirrhotic patients.

Background Neutralizing antibodies (NAbs) prevent pathogens from infecting host cells. Detection of SARS-CoV-2 NAbs is critical to evaluate herd immunity and monitor vaccine efficacy against SARS-CoV-2, the virus that causes COVID-19. All currently available NAb tests are lab-based and time-intensive. Method We develop a 10 min cellulose pull-down test to detect NAbs against SARS-CoV-2 from human plasma. The test evaluates the ability of antibodies to disrupt ACE2 receptor—RBD complex formation. The simple, portable, and rapid testing process relies on two key technologies: (i) the vertical-flow paper-based assay format and (ii) the rapid interaction of cellulose binding domain to cellulose paper. Results Here we show the construction of a cellulose-based vertical-flow test. The developed test gives above 80% sensitivity and specificity and up to 93% accuracy as compared to two current lab-based methods using COVID-19 convalescent plasma. Conclusions A rapid 10 min cellulose based test has been developed for detection of NAb against SARS-CoV-2. The test demonstrates comparable performance to the lab-based tests and can be used at Point-of-Care. Importantly, the approach used for this test can be easily extended to test RBD variants or to evaluate NAbs against other pathogens.

Importance: To examine the impact of SARS-CoV-2 vaccination of lactating mothers on human milk Objective: (1) To quantify SARS-CoV-2-specific immunoglobulin A (IgA) and immunoglobulin G (IgG) in human milk of lactating mothers who received the BNT162b2 vaccine, with reference to a cohort convalescent from antenatal COVID-19, and healthy lactating mothers. (2) To detect and quantify vaccine mRNA in human milk after BNT162b2 vaccination. Design: Gestational Immunity For Transfer 2 (GIFT-2) is a prospective cohort study of lactating mothers who were due to receive two doses of BNT162b2 vaccine, recruited between 5th February 2021 and 9th February 2021. Setting: Lactating healthcare workers living in Singapore Participants: Convenience sample of ten lactating healthcare workers. Human milk samples were collected at four time points: pre-vaccination, 1 to 3 days after dose one, 7 to 10 days after dose one, and 3 to 7 days after dose two of the BNT162b2 vaccine. Exposure: Two doses of the BNT162b2 vaccine 21 days apart. Main Outcome and Measure: (i) SARS-CoV-2-specific IgA and IgG in human milk of lactating mothers who received BNT162b2 vaccine, (ii) Detection and quantification of vaccine mRNA in human milk after BNT162b2 vaccination. Results: Ten lactating healthcare workers aged 32.5 years (range 29 to 42) were recruited, with 40 human milk samples collected and analysed. SARS-CoV-2-specific IgA was predominant in human milk of lactating mothers who received BNT162b2 vaccine. The sharpest rise in antibody production was 3 to 7 days after dose two of the BNT162b2 vaccine, with medians of 1110 picomolar of anti-SARS-CoV-2 spike and 374 picomolar of anti-Receptor Binding Domain IgA. Vaccine mRNA was detected only on rare occasions, at a maximum concentration of 2 ng/mL. Infants had no reported adverse events, up to 28 days after ingestion of post-vaccination human milk. Conclusions and Relevance: In this cohort of ten lactating mothers following BNT162b2 vaccination, nine (90%) produced SARS-CoV-2 IgA, and ten (100%) produced IgG in human milk with minimal amounts of vaccine mRNA. Lactating individuals should continue breastfeeding in an uninterrupted manner after receiving mRNA vaccination for SARS-CoV-2.

Aim: Toevaluate the value of an intraoperative bile leakage test during liver resection in preventing bile leakage after hepatic resection. Methods: A sterile fat emulsion was injected through the duct of the gallbladder among patients from the treatment group so as to observe leakage status on the hepatic resection plane; the leakage points were dealt with in time. The hepatic resection plane was treated using conventional methods among patients from the control group. Results: The incidence rates of the bile leakage and other complications in the two groups were analyzed in this study. Two (3.7%) of the 53 patients from the treatment group had bile leakage, and 8 (14.8%) of the 54 patients from the control group had bile leakage. There were significant differences between the two groups (p < 0.05) in terms of the incidence of the bile leakage. With regard to the incidence of other complications, there were no significant differences between the two groups (p > 0.05). Conclusions: An intraoperative bile leakage test appears to be sensitive in detecting interoperative bile leaks and can effectively prevent bile leakage after hepatic resection, and it does not increase the likelihood of other complications.

Our understanding of the conformational and electrostatic determinants that underlie targeting of human leukocyte antigens (HLA) by anti-HLA alloantibodies is principally based upon in silico modelling. Here we provide a biochemical/biophysical and functional characterization of a human monoclonal alloantibody specific for a common HLA type, HLA-A*11:01. We present a 2.4 Å resolution map of the binding interface of this antibody on HLA-A*11:01 and compare the structural determinants with those utilized by T-cell receptor (TCR), killer-cell immunoglobulin-like receptor (KIR) and CD8 on the same molecule. These data provide a mechanistic insight into the paratope−epitope relationship between an alloantibody and its target HLA molecule in a biological context where other immune receptors are concomitantly engaged. This has important implications for our interpretation of serologic binding patterns of anti-HLA antibodies in sensitized individuals and thus, for the biology of human alloresponses.