Managing severe warm autoimmune haemolytic anaemia after the SARS-Cov- 2 vaccine with emergency splenectomy and eculizumab

Autoimmune haemolytic anaemia (AIHA) is rare but described after the SARS-CoV- 2 Pfizer-BioNTech vaccine. We present a case of severe refractory warm AIHA after this vaccine, managed with emergency splenectomy and complement inhibition with eculizumab. A male in his teens with a history of liver transplant for biliary atresia (aged 2 years) and AIHA (aged 6 years) presented to his district general hospital with jaundice, dark urine, fatigue and chest discomfort 48 h after the first dose of SARS-CoV- 2 Pfizer-BioNTech vaccine (BNT162b2 mRNA). Investigations revealed haemoglobin (Hb) of 70 g/L and bilirubin of 98 mumol/L, which was treated as AIHA. The patient initially responded to prednisolone (1 mg/kg, 60 mg) but subsequently deteriorated and failed to respond to second-line rituximab (375 mg/m2) and two units of packed red blood cells (PRBC). By day 29 the patient had developed life-threatening anaemia culminating in a Hb of 35 g/L (after transfusion), lactate dehydrogenase (LD) of 1293 units/L and bilirubin of 228 mumol/L. This necessitated an immediate transfer to our tertiary centre for specialist support. Further investigations revealed a haptoglobin <0.1 g/L and direct antiglobulin test (DAT) strongly positive for IgG (4+) and negative for C3d. The peripheral blood film showed severe anaemia, nucleated red cells, anisocytosis and spherocytes with no autoagglutination, schistocytes or platelet clumps. Thrombocytopaenia (platelets 49 +/- 109/L) was present. Differentials were ruled out, such as paroxysmal nocturnal haemoglobinuria and heparin-induced thrombocytopaenia. HIV and hepatitis serology were negative, as were adenovirus, cytomegalovirus and Epstein-Barr virus PCR assays. A CT showed splenomegaly of 15.5 cm. Urinalysis found urobilinogen and bilirubin at high concentrations and negative urinary haemosiderin. Together, the investigations were consistent with warm AIHA. On day 29, four units of PRBC were transfused alongside 100 mg methylprednisolone and 1 g/kg IVIG. On day 30 the patient deteriorated despite the escalated treatment: Hb had only increased to 54 g/L, bilirubin was 200 mumol/L and LD was rising. Considering this life-threatening fulminant haemolysis, an emergency splenectomy was performed. This slowed haemolysis but did not completely ameliorate it: by day 33 the patient had received 15 units of PRBC. Thus, eculizumab, a terminal complement pathway inhibitor, was trialled to arrest intravascular haemolysis, alongside rituximab, repeat IVIG 1 g/kg, prednisolone 40 mg and tacrolimus 2 mg. This showed a favourable response, requiring less frequent transfusions and settling haemolysis. This case highlights the rare complication of warm AIHA with the SARS-CoV- 2 Pfizer-BioNTech vaccine, the use of emergency splenectomy for disease control, and the potential of eculizumab for refractory cases.

COVID-19 vaccines in patients with solid tumor cancers receiving immune checkpoint inhibitors

Background: The interaction between checkpoint inhibitors (CPI) and Sars-COV-2 vaccines has been understudied. One potential complication in pts receiving CPI is immune-mediated adverse events (irAEs) resulting from overactivation of the immune system. It is unknown whether concurrent CPI and Sars-COV-2 vaccine administration increases the risk of irAEs. This retrospective study examined the incidence of severe irAEs in cancer patients receiving CPI therapy at the time of vaccination against Sars CoV-2. Method(s): Following IRB approval, pts with solid tumors who received any approved CPI since FDA authorization of the COVID-19 vaccine in December 2020 were identified via institutional electronic health record. Pts who received one or more doses of an authorized vaccine within 60 days of CPI treatment were included. The primary endpoint was to evaluate the incidence of severe irAE (one or more of the following: grade 3 AE or above, multi-system involvement, need for hospitalization). Secondary endpoints included time between CPI and vaccination, need for immunosuppressive therapy, and rate of discontinuation of CPI due to irAE. Data was analyzed using descriptive statistics. Result(s): 290 pts with bladder, head/neck, liver, skin (melanoma, SCC), renal, and gynecologic cancer were included in analysis. The median age was 67 years (IQR: 59.0-74.0) and 66% pts were male. At the time of vaccination, 201 pts (69.3%) received CPI monotherapy, 53 pts (18.3%) received combination (combo) CPI therapy, and 36 pts (12.4%) received other therapies (chemo, TKIs, etc.) with CPI. The vaccine manufacturer was Pfizer Bio-N-Tech in 162 pts (55.9%), Moderna in 122 pts (42.1%), and Johnson and Johnson in 6 pts (2.1%). The number of vaccinations received was >/= 3 in 214 pts, 2 in 64 pts, and 1 in 11 pts. 30 pts (11.5%) experienced severe irAEs following vaccination. The rate of severe irAEs was 10.3% (30/290) in the total population [6% (12/201) with CPI monotherapy, 19% (10/53) with combo CPI, and 22% (8/36) in the combo CPI-other group]. Severe irAEs occurred after the first vaccine dose in 5 pts (16.7%), second dose in 16 pts (53.3%), and third dose in 9 pts (30%) pts. The median time between CPI treatment and vaccination in pts who experienced irAE was15.5 days (IQR: 10.2-23.0). Hospitalization was required for 19 patients (63.3%). 24 pts (80.0%) required immunosuppressive therapy with a median therapy duration of 98.5 days (IQR 40.2-173.0). 16 pts (53.5%) discontinued CPI therapy following severe irAEs Conclusion(s): In this retrospective study, we observed a 10.3% rate of severe irAE in cancer pts receiving CPI concurrently with COVID-19 vaccines. Further investigation in pts with additional cancer types is warranted to help determine best practice guidelines for COVID-19 vaccination in cancer patients receiving CPI.

Critical role of defensins in respiratory viral infection induced breast cancer progression

Respiratory viral infections (RVI) such as influenza and COVID19 impact the host systemic immune system along with causing deleterious chronic inflammatory responses and respiratory distress. While the role of chronic inflammation in cancer is well-established, the role of RVI on tumorigenesis is poorly defined. To study the role of RVI on breast cancer, we first infected murine respiratory epithelial cells (mRES) with murine sendai virus (mSV), an analog for human parainfluenza virus. These infected mRES were co-cultured with 4T1 murine breast cancer cells in 1:1 dilution on a single 2D plate and also in trans-well format. Both in co-culture and transwell culture we saw a 40- 80% (p<0.05) increased proliferation of breast cancer cells. Similarly, when 4T1 cells were treated with the supernatant collected from infected mRES cells in 1:5 dilution, also demonstrated a 2.3 fold increased breast cancer cell proliferation. The cytokine analysis from the supernatant collected from infected mRES cells demonstrated a 17-23 fold enhanced secretion of alpha/beta-defensins. Direct treatment of alpha-defensin (cyptidin-4, 10 pg/mL) and beta-defensin-3 (mBD3, 20 pg/mL) on 4T1 cells demonstrated enhanced expression of chemokine metastatic receptor, CXCR4 (4.3 fold), angiogenic factor, VEGF (12.8 fold) and cell division favoring factor, CDK2 (8.1 fold). Further, analysis of infected mRES cells demonstrated upregulation of toll-like receptor 2 (TLR2) and NODlike receptor protein 3 (NLRP3) expression. Interesting, co-cultured of infected mRES with syngeneic murine CD4 T cells induced exhaustion phenotype (PD1+ and CTLA4+ ) differentiation of CD4 T cells. Taken together, these data suggest that respiratory viral infections through induction of cancer cell proliferation and inhibiting anti-tumor adaptive immune responses promote breast cancer proliferation.

Metronidazole, acyclovir and tetrahydrobiopterin may be promising to treat COVID-19 patients, through interaction with interleukin-12.

COVID-19 patients have shown overexpressed serum levels of several pro-inflammatory cytokines, leading to a high mortality rate due to numerous complications. Also, previous studies demonstrated that the metronidazole (MTZ) administration reduced pro-inflammatory cytokines and improved the treatment outcomes for inflammatory disorders. However, the effect and mechanism of action of MTZ on cytokines have not been studied yet. Thus, the current study aimed to identify anti-cytokine therapeutics for the treatment of COVID-19 patients with cytokine storm. The interaction of MTZ with key cytokines was investigated using molecular docking studies. MTZ-analogues, and its structurally similar FDA-approved drugs were also virtually screened against interleukin-12 (IL-12). Moreover, their mechanism of inhibition regarding IL-12 binding to IL-12 receptor was investigated by measuring the change in volume and area. IL-12-metronidazole complex is found to be more stable than all other cytokines under study. Our study also revealed that the active sites of IL-12 are inhibited from binding to its target, IL-12 receptor, by modifying the position of the methyl and hydroxyl functional groups in MTZ. Three MTZ analogues, metronidazole phosphate, metronidazole benzoate, 1-[1-(2-Hydroxyethyl)-5-nitroimidazol-2-yl]-N-methylmethanimine-oxide, and two FDA-approved drugs acyclovir (ACV), and tetrahydrobiopterin (THB) were also found to prevent binding of IL-12 to IL-12 receptor similar to MTZ by changing the surface and volume of IL-12 upon IL-12-drug/ligand complex formation. According to the RMSD results, after 100 ns MD simulations of human IL-12-MTZ/ACV/THB drug complexes, it was also observed that each complex was swinging within a few Å compared to their corresponding docking poses, indicating that the docking poses were reliable. The current study demonstrates that three FDA-approved drugs, namely, metronidazole, acyclovir and tetrahydrobiopterin, are potential repurposable treatment options for overexpressed serum cytokines found in COVID-19 patients. Similar approach is also useful to develop therapeutics against other human disorders.

Chestnut inner shell extract inhibits viral entry of porcine epidemic diarrhea virus and other coronaviruses in vitro.

Porcine epidemic diarrhea virus (PEDV) is a coronavirus that causes acute diarrhea in suckling piglets. Although vaccines are able to reduce the incidence of PEDV infection, outbreaks of PEDV continue to be reported worldwide and cause serious economic losses in the swine industry. To identify novel antiviral sources, we identified the chestnut (Castanea crenata) inner shell (CIS) as a natural material with activity against PEDV infection in vitro. The ethanol fractions of CIS extracts potently inhibited PEDV infection with an IC90 of 30 µg/ml. Further investigation of the virus lifecycle demonstrated that CIS extract particularly targeted the early stages of PEDV infection by blocking viral attachment and membrane fusion at rates of 80~90%. In addition, CIS extract addition reduced the viral entry of other members of the Coronaviridae family. Our data demonstrated that CIS extract inhibited PEDV infection by blocking cell entry in vitro and suggest that CIS extract is a new prophylactic and therapeutic agent against PEDV and other coronavirus infections.

Exploring nanoselenium to tackle mutated SARS-CoV-2 for efficient COVID-19 management

Despite ongoing public health measures and increasing vaccination rates, deaths and disease severity caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new emergent variants continue to threaten the health of people around the world. Therefore, there is an urgent need to develop novel strategies for research, diagnosis, treatment, and government policies to combat the variant strains of SARS-CoV-2. Since the state-of-the-art COVID-19 pandemic, the role of selenium in dealing with COVID-19 disease has been widely discussed due to its importance as an essential micronutrient. This review aims at providing all antiviral activities of nanoselenium (Nano-Se) ever explored using different methods in the literature. We systematically summarize the studied antiviral activities of Nano-Se required to project it as an efficient antiviral system as a function of shape, size, and synthesis method. The outcomes of this article not only introduce Nano-Se to the scientific community but also motivate scholars to adopt Nano-Se to tackle any serious virus such as mutated SARS-CoV-2 to achieve an effective antiviral activity in a desired manner.

Negative and positive antecedents of intention to resume hotel consumption in new normal settings in Malaysia: insight from three psychological theories

PurposeApplying three psychological theories, this study aims to attempt to investigate the role of consumer psychology, specifically the factors of trust in vaccination, threat severity, fear, anxiety, risk and hygiene, and safety, on intention to resume hotel consumption. The authors also tested the mediation effect of anxiety among psychological constructs: perceived threat, fear and risk with the intention to resume hotel consumption.Design/methodology/approachUsing purposive sampling, data were collected from 470 respondents from four cities in Malaysia and analysed by applying analysis of moment structures (AMOS) structural equation model technique. The respondents for this study were frequent travellers meaning the leisure tourists who at least travel twice a year or travel when getting the occasion to explore new things. In this study, an online survey was employed to ensure easy accessibility and to enhance the number of replies.FindingsThe results of this study confirmed that perceived severity, risk and fear influence travellers' anxiety. This study further confirms that trust in vaccination and hygiene & safety provided by the hotelier reduces anxiety levels. Anxiety is found one of the most important predictors of intention to resume hotel consumption, which further mediates the relationship between other psychological variables: perceived severity, risk, fear and intention to resume hotel consumption. Anxiety mediates the relationship between perceived severity, fear and intention to resume hotel consumption and partially mediates the association between risk and intention to resume hotel consumption.Originality/valueThis study examined three psychological theories and extended them by including the trust in vaccination and the hygiene and safety constructs. Anxiety was investigated as a mediator.

A Potential Therapeutic Target Underling Binge Alcohol-Triggered Spontaneous Arrhythmia Onset in the Aged Heart

Background: Aging and binge alcohol abuse are both known as independent risk factors for both atrial and ventricular arrhythmias. With the COVID-19 pandemic, increased social isolation has significantly increased alcohol consumption worldwide. Older adults are a high-risk drinking group and alcohol significantly enhances the risk of arrhythmia onset. Yet, how alcohol (a secondary stressor) drives spontaneous atrial and ventricular arrhythmia onset in the aged heart (a primary stressor) remains unclear. Objective(s): We recently reported the stress-response kinase c-jun N-terminal kinase 2 (JNK2) underlies alcohol-enhanced atrial arrhythmia vulnerability (pacing-induced) in healthy young hearts. Here, we reveal a critical role of JNK2 in alcohol-driven arrhythmia onset in the aged heart in vivo. Method(s): Ambulatory ECGs were recorded using wireless telemeters in binge alcohol-exposed aged (24 months) and young mice (2 months). Spontaneous premature atrial and ventricular contractions (PACs, PVCs), atrial and ventricular tachycardia (AT, VT) were quantified as previously described. The role of JNK2 in triggered arrhythmic activities was assessed using a well-evaluated JNK2-specific inhibitor and our unique cardiac-specific MKK7D and MKK7D-JNK2dn mouse models with tamoxifen inducible overexpression of constitutively active MKK7 (a JNK upstream activator) or co-expression of MKK7D and inactive dominant negative JNK2 (JNK2dn). Result(s): We found that binge alcohol exposure in aged mice (n=14) led to spontaneous PACs/PVCs (75% of the mice), and AT/VT episodes (50%) along with a 21% mortality rate. However, alcohol-exposed young (n=5) and non-alcohol-exposed aged mice (n=11) were absent of any spontaneous arrhythmic activities or premature death. Intriguingly, JNK2-specific inhibition in vivo abolished those alcohol-associated triggered activities and mortality in aged mice. The causative role of JNK2 in triggered arrhythmias and premature death was further supported by the high frequency of spontaneous PACs/PVCs and nonsustained AT/VT episodes along with a 50% mortality rate in MKK7D mice (n=10), which was strikingly alleviated in MKK7D-JNK2dn mice (n=5) with cardiac-specific JNK2 competitive inhibition. Conclusion(s): Our findings are the first to reveal that stress kinase JNK2 underlies binge alcohol-evoked atrial and ventricular arrhythmia initiation in aged mice. Modulating JNK2 could be a novel therapeutic strategy to treat and/or prevent binge drinking-evoked cardiac arrhythmias.Copyright © 2023

Incidence and sero-surveillance of feline viruses in Korean cats residing in Gyeonggi-do

Incidences of major feline viral diseases provide basic information for preventing viral disease in cats. Despite the growing interest in feline viral diseases, sero-surveillances have been lacking. In this study, we analyzed the diagnoses of feline viral diseases and conducted a sero surveillance of feline panleukopenia virus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), and feline infectious peritonitis virus (FIPV) in Korean cats. Of the 204 confirmed cases since 2015, the numbers of diagnoses for FPV, FIPV, FCV, feline influenza virus, and FHV-1 were 156, 32, 12, 3, and 1 case, respectively. In total, 200 sera, collected between 2019 and 2021, were screened for the presence of antibodies against FPV, 2 FCVs, FHV-1, and FIPV using a hemagglutination inhibition test and a virus-neutralizing assay (VNA). The overall seropositive rates in cats tested for FPV, the 2 FCVs, FHV-1, and FIPV were 92.5%. 42.0%, 37.0%, 52.0%, and 14.0%, respectively. A low correlation (r = 0.466) was detected between the VNA titers of 2 FCV strains. The highest incidence and seropositive rate of FPV reveal that FPV is circulating in Korean cats. The low r-value between 2 FCVs suggests that a new feline vaccine containing the 2 kinds of FCVs is required.

Molecular genetics and genomics of the ABO blood group system

The A and B oligosaccharide antigens of the ABO blood group system are produced from the common precursor, H substance, by enzymatic reactions catalyzed by A and B glycosyltransferases (AT and BT) encoded by functional A and B alleles at the ABO genetic locus, respectively. In 1990, my research team cloned human A, B, and O allelic cDNAs. We then demonstrated this central dogma of ABO and opened a new era of molecular genetics. We identified four amino acid substitutions between AT and BT and inactivating mutations in the O alleles, clarifying the allelic basis of ABO. We became the first to achieve successful ABO genotyping, discriminating between AA and AO genotypes and between BB and BO, which was impossible using immunohematological/serological methods. We also identified mutations in several subgroup alleles and also in the cis-AB and B(A) alleles that specify the expression of the A and B antigens by single alleles. Later, other scientists interested in the ABO system characterized many additional ABO alleles. However, the situation has changed drastically in the last decade, due to rapid advances in next-generation sequencing (NGS) technology, which has allowed the sequencing of several thousand genes and even the entire genome in individual experiments. Genome sequencing has revealed not only the exome but also transcription/translation regulatory elements. RNA sequencing determines which genes and spliced transcripts are expressed. Because more than 500,000 human genomes have been sequenced and deposited in sequence databases, bioinformaticians can retrieve and analyze this data without generating it. Now, in this era of genomics, we can harness the vast sequence information to unravel the molecular mechanisms responsible for important biological phenomena associated with the ABO polymorphism. Two examples are presented in this review: the delineation of the ABO gene evolution in a variety of species and the association of single nucleotide variant (SNV) sites in the ABO gene with diseases and biological parameters through genome-wide association studies (GWAS).Copyright © Annals of Blood. All rights reserved.

In silico identification of the potential natural inhibitors of SARS-CoV-2 Guanine-N7 methyltransferase

Background: The outbreak of the COVID-19 pandemic caused by the SARS-CoV-2 has triggered intense scientific research into the possible therapeutic strategies that can combat the ravaging disease. One of such strategies is the inhibition of an important enzyme that affects an important physiological process of the virus. The enzyme, Guanine-N7 Methyltransferase is responsible for the capping of the SARS-CoV-2 mRNA to conceal it from the host's cellular defense. The aim of the study: This study aims at computationally identifying the potential natural inhibitors of the SARS-CoV-2 Guanine-N7 methyltransferase binding at the active site (Pocket 41). Material(s) and Method(s): A library of small molecules was obtained from edible African plants and was molecularly docked against the SARS-CoV-2 Guanine-N7 methyltransferase (QHD43415_13. pdb) using the Pyrx software. Sinefungin, an approved antiviral drug had a binding score of -7.6 kcal/ mol with the target was chosen as a standard. Using the molecular descriptors of the compounds, virtual screening for oral availability was performed using the Pubchem and SWISSADME web tools. The online servers pkCSM and Molinspiration were used for further screening for the pharmacokinetic properties and bioactivity respectively. The molecular dynamic simulation and analyses of the Apo and Holo proteins were performed using the GROMACS software on the Galaxy webserver. Result(s): With a total RMSD of 77.78, average RMSD of 3.704, total regional (active site) RMSF of 30.61, average regional RMSF of 1.91, gyration of 6.9986, and B factor of 696.14, Crinamidine showed the greatest distortion of the target. Conclusion(s): All the lead compounds performed better than the standard while Crinamidine is predicted to show the greatest inhibitory activity. Further tests are required to further investigate the inhibitory activities of the lead compounds.Copyright © 2022 Belgorod State National Research University. All right reserved.

No Dose Adjustments for Cyp3a4 Substrates When Coadministered with Bemnifosbuvir

Background: Bemnifosbuvir (BEM, AT-527) is a guanosine nucleotide prodrug in development for the treatment of COVID-19 and chronic HCV. BEM was identified in vitro as an inhibitor [competitive and time-dependent inhibition (TDI)] and inducer of CYP3A4, prompting evaluation of the clinical relevance of these results in a Ph 1 drug-drug interaction (DDI) study in healthy participants using midazolam (MDZ), a sensitive CYP3A4 substrate as an index drug. Method(s): Two groups of 12 healthy participants were enrolled and received a single dose of 2mg MDZ alone on Day 1. Between Days 3 and 7 inclusive, all participants received oral BEM 550mg twice daily (BID). On day 3 and day 7, Group A received a single dose of 2mg MDZ simultaneously with BEM;Group B on these two days received 2mg MDZ 2h after BEM. Serial plasma samples were obtained and measured for MDZ and 1-OH-MDZ levels. Result(s): A single dose (simultaneous or staggered) of BEM slightly increased the plasma exposure of MDZ (14%-26%). Staggered BEM had less impact (8%-17%) on 1-OH-MDZ than simultaneous dosing (22%-31%). Inhibitory effect of BEM was more pronounced with repeat dosing, consistent with in vitro data showing TDI on CYP3A4. After repeat dosing, simultaneously administered BEM increased plasma MDZ exposure by 83%-98%, without affecting the exposure of 1-OH-MDZ. With repeat dosing, staggered BEM showed less effect on both MDZ and 1-OH-MDZ. There was no effect on vital signs, ECG, and no SAEs or drug discontinuations. Conclusion(s): BEM is a weak inhibitor (ratio between 1.25 and 2) of CYP3A4. No dose adjustment is needed for drugs that are substrates of CYP3A4 when co-administered with BEM.

Single-Cell Analysis Reveals Characteristics of Myeloid Cells in Pulmonary Pasc

Background: Although our understanding of immunopathology in the risk and severity of COVID-19 disease is evolving, a detail of immune response in long-term consequences of COVID-19 infection remains unclear. Recently, few studies have detailed the immune and cytokine profiles associated with PASC. However, dysregulation of immune system driving pulmonary PASC is still largely unknown. Method(s): To characterize the immunological features of PPASC, we performed droplet-based scRNA-sequencing using 10X genomics to study the transcriptomic profiles of peripheral blood mononuclear cells (PBMCs) from participants naive to SARS-CoV-2 (NP, n=2) and infected with SARS-CoV-2 with chronic pulmonary symptoms (PPASC, n=2). Result(s): Analysis of more than 34,000 PBMCs by integrating our dataset with previously reported control datasets generated cell distribution and identified 11 immune cell types based on canonical gene expression. The proportion of myeloid-lineage cells (CD14+monocyte, CD16+monocyte, and dendritic cells) and platelets were increased in PPASC compared with those of NP. Specifically, PPASC displayed up-regulation of VEGFA and transcription factors, such as ATF2, ELK, and SMAD in myeloid-lineage cells. Also, TGF-beta and WNT signaling pathways were up-regulated in these cell population. Cell-cell interaction analysis identified that myeloid-lineage cells in PPASC participated in regulation of fibrosis and immune response, such as VEGFA (increased) and MIF (decreased) interactions. Conclusion(s): Together, this study provides high-resolution insights into immune landscape in PPASC. Our results emphasize differences in myeloid lineage-mediated fibrosis and immunity between PPASC and NP, suggesting they could act as potential pathological drivers of PPASC. (Figure Presented).

MECHANISM AND RESISTANCE STUDIES OF SARS-CoV-2 MPRO INHIBITOR POMOTRELVIR (PBI-0451)

Background: The unprecedented scale of the COVID-19 pandemic and rapid evolution of SARS-CoV-2 variants underscores the need for broadly active inhibitors with a high barrier to resistance. The coronavirus main protease (Mpro) is an essential viral enzyme required for viral polyprotein processing and is highly conserved across human coronaviruses. Pomotrelvir (PBI-0451) is a novel Mpro inhibitor currently completing phase 2 clinical trial. Here we describe the mechanism of action, broad activity against SARS-CoV-2 clinical isolates, combination studies with other SARS-CoV-2 inhibitors and favorable resistance profile of pomotrelvir. Method(s): The kinetic parameters of pomotrelvir Mpro inhibition and its interaction with nirmaltrevir were determined in a kinetic protease assay. The IC50s of pomotrelvir on mutant Mpro proteins were measured in an endpoint Mpro assay. Combination studies of pomotrelvir with remdesivir and molnupiravir were carried out in A549-hACE2 cells infected with SARS-CoV-2 NLuc virus. Activity against SARS-CoV-2 clinical variants was assessed by infection of A549-ACE2-TMPRSS2 cells followed by immunostaining of the viral nucleocapsid protein. Result(s): Pomotrelvir is a potent competitive inhibitor of SARS-CoV-2 Mpro (Ki =2.7 nM). Binding of pomotrelvir and the Mpro inhibitor nirmatrelvir to the active site is mutually exclusive. In the SARS-CoV-2 NLuc assay, pomotrelvir is additive when combined with remdesivir or molnupiravir, two nucleoside analogs targeting viral RNA synthesis. When the effect of Mpro substitutions previously selected in a resistance study of pomotrelvir were analyzed in an enzyme assay, only Mpro-N133H showed a significant increase in IC50 (45-fold). The catalytic efficiency of Mpro-N133H is reduced by 10-fold and the recombinant virus SARSCoV-2 (WA1) -N133H is not viable, suggesting that N133H has lower replicative fitness. Lastly, pomotrelvir exhibits broad activity against all SARS-CoV-2 clinical isolates tested to date, including five omicron variants. Conclusion(s): PBI-0451 is a potent competitive inhibitor of SARS-CoV-2 Mpro and is broadly active against SARS-CoV-2 clinical isolates including omicron variants. Results from inhibitor interaction studies support the potential combination of pomotrelvir with remdesivir and molnupiravir but not nirmatrelvir. Enzymatic characterization of in vitro selected pomotrelvir resistant variants indicates they either confer no resistance or have reduced fitness.

Computer Analysis of the Inhibition of ACE2 by Flavonoids and Identification of Their Potential Antiviral Pharmacophore Site.

In the present study, we investigated the antiviral activities of 17 flavonoids as natural products. These derivatives were evaluated for their in vitro antiviral activities against HIV and SARS-CoV-2. Their antiviral activity was evaluated for the first time based on POM (Petra/Osiris/Molispiration) theory and docking analysis. POM calculation was used to analyze the atomic charge and geometric characteristics. The side effects, drug similarities, and drug scores were also assumed for the stable structure of each compound. These results correlated with the experimental values. The bioinformatics POM analyses of the relative antiviral activities of these derivatives are reported for the first time.

Mucin-Inspired Single-Chain Polymer (MIP) Fibers as Potent SARS-CoV-2 Inhibitors.

Mucins are the key component of the defensive mucus barrier. They are extended fibers of very high molecular weight with diverse biological functions depending strongly on their specific structural parameters. Here, we present a mucin-inspired nanostructure, produced via a synthetic methodology to prepare methacrylate-based dendronized polysulfates (MIP-1) on a multi gram-scale with high molecular weight (MW=450 kDa) and thiol end-functionalized mucin-inspired polymer (MIP) via RAFT polymerization. Cryo-electron tomography (Cryo-ET) analysis of MIP-1 confirmed a mucin-mimetic wormlike single-chain fiber structure (length=144±59 nm) in aqueous solution. This biocompatible fiber showed promising activity against SARS-CoV-2 and its mutant strain, with a remarkable low half maximal (IC50 ) inhibitory concentration (IC50 =10.0 nM). Additionally, we investigate the impact of fiber length on SARS-CoV-2 inhibition by testing other functional polymers (MIPs) of varying fiber lengths.

SARS-CoV-2 Binding and Neutralization Properties of Peptides Derived from N-Terminus of Human ACE2.

The binding properties of synthetic and recombinant peptides derived from N-terminal part of ACE2, the main receptor for SARS-CoV-2, were evaluated. Additionally, the ability of these peptides to prevent virus entry in vitro was addressed using both pseudovirus particles decorated with the S protein, as well as through infection of Vero cells with live SARS-CoV-2 virus. Surprisingly, in spite of effective binding to S protein, all linear peptides of various lengths failed to neutralize the viral infection in vitro. However, the P1st peptide that was chemically "stapled" in order to stabilize its alpha-helical structure was able to interfere with virus entry into ACE2-expressing cells. Interestingly, this peptide also neutralized pseudovirus particles decorated with S protein derived from the Omicron BA.1 virus, in spite of variations in key amino acid residues contacting ACE2.

In silico evaluation of some commercially available terpenoids as spike glycoprotein of SARS-CoV-2 - inhibitors using molecular dynamic approach.

Coronavirus, an extremely contagious infections disease had a harmful effect on the world's population. It is a family of enveloped, single-stranded, positive-strand RNA viruses of Nidovirales order belongs to coroviridae family. At present, worldwide several lakhs of deaths and several billions of infections have been reported. Hence, the focus of the present study was to assess the SARS-CoV-2 enzyme inhibitory potential of certain commercially available terpenoids using Lamarckian genetic algorithm as a working principle and molecular dynamic studies was also performed. AutoDock 4.2 software was used to perform the computational docking calculations of terpenoids against SARS-CoV-2 enzyme. The terpenoids such as, Andrographolide, Betulonic acid, Erythrodiol, Friedelin, Mimuscopic acid, Moronic acid, and Retinol were selected based on the drug likeness properties. Remdesivir a well-known anti-viral drug was selected as the standard drug. Molecular dynamic simulation studies were carried using Desmond module of Schrodinger Suite. In the current study we observed that, Friedelin was exhibited excellent SARS-CoV-2 enzyme inhibitory potential than the standard drug and other selected terpenoids. Friedelin and the standard Remdesivir was undergone the molecular dynamic studies and Friedelin showed a good number of hydrogen bonds over the simulation time of 100 ns. Based on the in silico computational evaluation, it can be concluded that Friedelin could be worthwhile terpenoid against SARS-CoV-2 spike protein. A further study on Friedelin is required to develop a potential chemical entity against the management of COVID disease.Communicated by Ramaswamy H. Sarma.

A Developmental Pathway From Early Behavioral Inhibition to Young Adults' Anxiety During the COVID-19 Pandemic.

Objective: The COVID-19 pandemic has brought unprecedented changes to young adults' lives, resulting in mental health difficulties for many; however, some individuals are particularly prone to heightened anxiety. Little is known about the early life predictors of anxiety during the pandemic. We examined a developmental pathway from behavioral inhibition (BI), a temperament characterized by fearful responses toward novelty, to changes in young adults' anxiety during the initial period of the pandemic. We hypothesized that a stable pattern of BI across early childhood would predict greater adolescent worry dysregulation, which in turn would predict increases in young adult anxiety during a stressful phase of the pandemic. Method: Participants (N = 291; 54% female) were followed from toddlerhood to young adulthood. BI was observed at ages 2 and 3 years. Social wariness was observed at age 7 years. Participants rated their worry dysregulation in adolescence (age 15) and anxiety in young adulthood (age 18) at 2 assessments during the COVID-19 pandemic, 1 month apart. Results: A significant moderated mediation, in which a stable pattern of BI from toddlerhood to childhood, as compared to the absence of this pattern, predicted greater worry dysregulation in adolescence. Worry dysregulation predicted elevated young adult anxiety in the second assessment during COVID-19, even after accounting for the first assessment. Conclusion: This study identifies a developmental pathway from toddlerhood BI to young adults' elevated anxiety during the COVID-19 pandemic. Findings have implications for early identification of individuals at risk for dysregulated worry and the prevention of anxiety during stressful life events in young adulthood.Reprinted from J Am Acad Child Adolesc Psychiatry, 60, Zeytinoglu et al., A Developmental Pathway From Early Behavioral Inhibition to Young Adults' Anxiety During the COVID-19 Pandemic, pp. 1300-1308, copyright 2021, with permission from Elsevier.

Antibody responses to mRNA versus non-mRNA COVID vaccines among the Mongolian population.

Background: A nationwide vaccination program against coronavirus disease 2019 (COVID-19) was started in Mongolia 4 months after the first local transmission, which occurred in November 2020. Previous studies have reported that two doses of COVID-19 vaccine result in increased antibody against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A study was conducted in Mongolia 2 weeks after the second vaccine dose. In the present study, the serum levels of antibodies of individuals 6 months after natural SARS-CoV-2 infection were compared with those of individuals who had not been infected or had been infected but had received two doses of vaccine, including BNT162b2, ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BBIBP-CorV, which were used for COVID-19 in Mongolia. Methods: Of the 450 participants in this study, 237 (52.66%) were female and 213 (47.33%) were male. Four hundred people with or without SARS-CoV-2 infection who received two doses of 4 different COVID-19 vaccine participated in the vaccine groups and vaccine plus SARS-CoV-2 infection groups (50 in each group) and 50 individuals previously infected with SARS-CoV-2 participated in the unvaccinated group. Total antibody against SARS-CoV-2 infection, anti-SARS-CoV-2 N and S protein human IgG, and antibody inhibiting RBD-ACE2 binding were tested. Results: In the BNT162b2 vaccine group, total antibody against SARS-CoV-2 remained constant until 6 months, while the other vaccine groups showed a significant decrease, as compared to the unvaccinated group. The level of anti-SARS-CoV-2 S-RBD protein IgG was significantly increased in the ChAdOx1 n-CoV-19, Gam-COVID-Vac, and BNT162b2 vaccines groups as compared to the unvaccinated group. Participants in the BNT162b2 vaccine group had higher ACE2 inhibition efficiency compared to the other vaccine groups as well as the unvaccinated group. Conclusions: The BNT162b2 vaccine showed the highest level of antibody against SARS-CoV-2, followed by the BBIBP-CorV, Gam-COVID-Vac, and ChAdOx1 n-CoV-19 vaccines. The level of antibodies was increased in people infected with SARS-CoV-2 after vaccination, as compared to uninfected but vaccinated individuals.