Modeling DNA Oligonucleotide Binding to DNA-mimetic Stem-Loop 1 of the SARS-CoV-2 RNA

SARS-CoV-2 is a positive-sense RNA virus that contains open reading frame 1ab (ORF1ab) to produce 16 nonstructural proteins (nsps). Five stem-loops (SL) are found in the 5' UTR of the RNA that are involved in myriad viral functions and are labeled SL1 through SL5. SL1 is crucial to viral replication. Upon viral infection, nsp1 binds the ribosomal 40S subunit to inhibit all host mRNA translation. Upon SL1 binding to nsp1, viral mRNA can be processed by the ribosome, allowing viral proteins to be produced. In this study, we are examining small DNA oligonucleotides that bind to SL1-mimetic DNA in order to block SL1-nsp1 interactions. We designed a DNA analog of the SL1 hairpin and two small DNA oligonucleotides that are complementary to either the helical stem or the loop region of SL1. The binding of these oligonucleotides to the SL1 hairpin should allow the formation of either an alternate duplex or a triplex structure. Isothermal titration calorimetry (ITC) and circular dichroism (CD) techniques were performed in 1 MKCl and 10 mM MgCl2 at two different pH (5.5 and 7.0) to examine structural and thermodynamics of binding. ITC of the two oligonucleotides showed modest binding. Results from DNA binding experiments, thermal denaturation, and CD show the hairpin structure is thermodynamically more favored and mostly remains intact under the conditions examined.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Evaluation of expression and titration of recombinant nucleocapsid protein as an immunogenic candidate against SARS-CoV2

Introduction: Covid-19 epidemic results from an infection caused by SARS-CoV2. Evolution-based analyses on the nucleotide sequences show that SARS-CoV2 is a member of the genus Beta-coronaviruses and its genome consists of a single-stranded RNA, encoding 16 proteins. Among the structural proteins, the nucleocapsid is the most abundant protein in virus structure, highly immunogenic, with sequence conservatory. Due to a large number of mutations in the spike protein, the aim of this study was to investigate bioinformatics, expression of nucleocapsid protein and evaluate its immunogenicity as an immunogenic candidate. Materials and Methods: B and T cell epitopes of nucleocapsid protein were examined in the IEDB database. The PET28a-N plasmid was transferred to E. coli BL21(DE3) expression host, and IPTG induced recombinant protein expression. The protein was purified using Ni-NTA column affinity chromatography, and the Western blotting method was utilized to confirm it. Finally, mice were immunized with three routes of purified protein. Statistical analysis of the control group injection and test results was carried out by t-test from SPSS software. Results: The optimized gene had a Codon adaptation index (CAI) of 0/97 Percentage of codons having high- frequency distribution was improved to 85%. Expression of recombinant protein in E. coli led to the production of BoNT/B-HCC with a molecular weight of 45 kDa. The total yield of purified protein was 43 mg/L. Immunization of mice induced serum antibody response. Statistical analysis showed that the antibody titer ratio was significantly different compared to the control sample and the antibody titer was acceptable up to a dilution of 1.256000. Conclusion: According to the present study results, the protein can be used as an immunogenic candidate for developing vaccines against SARS-CoV2 in future research.

Safety, tolerability and efficacy of up-titration of guideline-directed medical therapies for acute heart failure in elderly patients: A sub-analysis of the STRONG-HF randomized clinical trial.

AIMS: STRONG-HF examined a high-intensity care (HIC) strategy of rapid up-titration of guideline-directed medical therapy (GDMT) and close follow-up after acute heart failure (AHF) admission. We assess the role of age on efficacy and safety of HIC. METHODS AND RESULTS: Hospitalized AHF patients, not treated with optimal GDMT were randomized to HIC or usual care. The primary endpoint of 180-day death or HF readmission occurred equally in older (>65 years, n = 493, 74 ± 5 years) and younger patients (53 ± 11 years, adjusted hazard ratio [aHR] 1.02, 95% confidence interval [CI] 0.73-1.43, p = 0.89). Older patients received slightly lower GDMT to day 21, but same doses at day 90 and 180. The effect of HIC on the primary endpoint was numerically higher in younger (aHR 0.51, 95% CI 0.32-0.82) than older patients (aHR 0.73, 95% CI 0.46-1.15, adjusted interaction p = 0.30), partially related to COVID-19 deaths. After exclusion of COVID-19 deaths, the effect of HIC was similar in younger (aHR 0.51, 95% CI 0.32-0.82) and older patients (aHR 0.63, 95% CI 0.32-1.02, adjusted interaction p = 0.56), with no treatment-by-age interaction (interaction p = 0.57). HIC induced larger improvements in quality of life to day 90 in younger (EQ-VAS adjusted-mean difference 5.51, 95% CI 3.20-7.82) than in older patients (1.77, 95% CI -0.75 to 4.29, interaction p = 0.032). HIC was associated with similar rates of adverse events in older and younger patients. CONCLUSION: High-intensity care after AHF was safe and resulted in a significant reduction of all-cause death or HF readmission at 180 days across the study age spectrum. Older patients have smaller benefits in terms of quality of life.

Low Barrier Tele-Buprenorphine in the Time of COVID-19: A Case Report

Background: To reduce the spread of coronavirus disease 2019 (COVID-19), many substance use disorder treatment programs have transitioned to telemedicine. Emergency regulatory changes allow buprenorphine initiation without an in-person visit. We describe the use of videoconferencing for buprenorphine initiation combined with street outreach to engage 2 patients experiencing homelessness with severe opioid use disorder (OUD). Case Presentation: Patient 1 was a 30-year-old man with severe OUD who had relapsed to injection heroin/fentanyl after incarceration. A community drop-in center outreach harm reduction specialist facilitated a videoconference with an addiction specialist at an OUD bridge clinic. The patient completed a community buprenorphine/naloxone initiation and self-titrated to his prior dose, 8/2 mg twice daily. One week later, he reconnected with the outreach team for a follow-up videoconference visit. Patient 2, a 36-year-old man with severe OUD, connected to the addiction specialist via a syringe service program harm reduction specialist. He had been trying to connect to a community buprenorphine/naloxone provider, but access was limited due to COVID-19, so he was using diverted buprenorphine/naloxone to reduce opioid use. He was restarted on his previous dose of 12/3 mg daily which was continued via phone follow-up 16 days later. Conclusion(s): COVID-19-related regulatory changes allow buprenorphine initiation via telemedicine. We describe 2 cases where telemedicine was combined with street outreach to connect patients experiencing homelessness with OUD to treatment. These cases highlight an important opportunity to provide access to life-saving OUD treatment for vulnerable patients in the setting of a pandemic that mandates reduced face-to-face clinical interactions.Copyright © 2020 Lippincott Williams and Wilkins. All rights reserved.

Determining the Effect of KmtR Mutants, E101Q, H102Q, and H111Q on the Metal Binding Affinities

Mycobacterium tuberculosis is the second leading infectious killer after COVID-19. The bacteria utilizes several metal transport systems to help it survive in the host.With an increase in the number of multiresistant, extensively resistant and totally drug-resistant strains, the development of new therapeutic strategies that target other essential pathways in the bacteria is critical. The bacteria contain several metal transport systems which are necessary for its survival. Additionally, the bacteria has two metalloregulators that are associated with nickel and cobalt export, NmtR and KmtR. The focus of this research is on KmtR, which represses the expression of the genes, cdf (which encodes the export protein) and kmtR. The goal of our research is to identify the residues that are responsible for binding the cognate metals, nickel and cobalt, as well as the noncognate metal, zinc, to KmtR. Mutagenesis studies coupled with metal binding experiments will be used to determine how KmtR binds these metals. The E101Q, H102Q, and H111Q mutants, among others, have been made, expressed, and purified in our lab. Data obtained from Isothermal Titration Calorimetry determined that all three mutant proteins bind cobalt with nanomolar affinities and the H111Q mutant KmtR proteins binds cobalt an order of magnitude weaker than the other two mutant proteins. Research reported as supported fully by the RI Institutional Development Award (IDeA) Network for Biomedical Research Excellence (RI-INBRE) from the National Institute of General Medical Sciences of the National Institutes of Health under grant #P20GM103430.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

Development of Aptasensor for the Diagnosis of Covid-19

Objectives: The objective is to develop a low-cost, practical, portable aptasensor platform for the diagnosis of COVID-19. Materials -Methods: Amino-terminated aptamers to be used for the design of an aptasensor were synthesized by SELEX method, and interaction of aptamers with SARS-CoV-2 S1 protein was investigated by isothermal titration calorimetry (ITC). Gold electrodes were used to design the biosensor platform. After the electrode surface was functionalized with cysteamine, the amino-terminated aptamer was conjugated to the surface via glutaraldehyde crosslinker. Then, the surface characterization and analytical parameters of the designed sensing platform were determined by adding commercial S1 proteins on the surface using differential pulse voltammetry (DPV), cyclic voltammetry (CV) and impedance spectroscopy (EIS). To evaluate the working performance of the system, S1 proteins were added to the synthetic serum samples using the standard addition method and the measurements were repeated. Result(s): Surface characterization of the platform designed with EIS and CV measurements was performed and it was found that the modification was successfully performed. In addition, DPV results and analytical parameters of the platform (calibration plot, limit of detection(LOD) , repeatability, coefficient of variation) were determined and the working performance of system was evaluated. Moreover, working performance of the biosensor in real samples and its specificity for COVID -19 were determined by experiments with synthetic serum and influenza A and B proteins. Conclusion(s): According the results, the system has potential to be used for the detection of COVID -19, and also it can be rapidly adapted in different pandemic situations that may occur in the future.

Successful matched unrelated donor hematopoietic stem cell transplantation for infantile Wolman disease

Introduction: Wolman disease is a rare genetic disorder with an autosomal recessive inheritance. A mutation in the LIPA gene causes lysosomal acid lipase (LAL) deficiency results in lipid storage and adrenal insufficiency. Death in early infancy is due to liver failure. Patients and methods: We describe the clinical course of a three-month-old infant diagnosed with Wolman disease. A rapid mutational analysis confirmed a LIPA gene defect. Results: He underwent matched unrelated donor peripheral blood stem cell hematopoietic stem cell transplantation (HSCT) at 3 months of age, with a treosulfan-based conditioning, which resulted in engraftment with donor-derived hematopoietic cells. He required supportive care for sinusoidal obstruction syndrome and mucositis. He was administered low dose prednisolone for grade I skin graft versus host disease, and a complete donor chimerism was documented on several occasions. At one year post HSCT, his growth and development were optimal, and there was no hepatosplenomegaly. He is maintained on glucocorticoid and mineralocorticoid supplements for primary hypoaldosteronism. Conclusion: The case emphasizes the timely diagnosis and the potential for successful treatment of Wolman disease by HSCT. © 2022 Pediatric Hematology Oncology Chapter of Indian Academy of Pediatrics

Towards New Antimicrobials - Targeting Bacterial Response Regulators

Purpose of Study: Antibiotic resistance remains one of the largest healthcare and public health challenges. Several studies have documented that the spread of antibiotic resistant bacteria in nosocomial settings has been exacerbated worldwide due to increased rates of hospitalization and intubation in the wake of the COVID-19 pandemic. One way to address antibiotic resistance is to identify novel compounds that inhibit essential microbial processes. Two-component regulatory systems are important mediators of signal transduction that allow bacteria to communicate with and respond to changes in their environment. The WalRK system is a two-component system that is conserved and essential for viability in many Gram-positive human pathogens. We hypothesize that a ligand that specifically binds with the DNA-interaction surface of the WalR protein can lead to cell death and can serve as a lead compound for future drug development efforts. Methods Used: We describe the development process of an assay to identify WalR binding compounds. In silico molecular dynamics docking approaches were utilized to identify potential WalR binding compounds from virtual compound libraries. To assess their WalR-binding capacity in vitro, overexpression strains for several WalR recombinant constructs were engineered and protein constructs were purified to homogenicity. Isothermal titration calorimetry (ITC) is a technique that measures heat release or absorption when two molecules interact. A MicroCal PEAQ ITC instrument was utilized to develop a WalR-binding assay. Summary of Results: WalR is a two-domain protein featuring a regulatory and a DNA-binding domain. Two constructs, a truncated DNA-binding domain and a full-length protein construct proved soluble, and pure quantities necessary to conduct ITC measurements could be successfully obtained (12 mg full-length protein and 23 mg truncated protein). These proteins were amenable to ITC experiments. We found that experiments were best run with at least a two-fold increase of ligand concentration to protein concentration supplied in identical buffer conditions over nineteen injections. We are currently assessing the binding affinities of our in silico hit compounds. Conclusion(s): Our results show that ITC enables the detailed, rapid, and reproducible characterization of the binding relationship between the DNA-binding domain of the WalR protein and any potential ligands. The protocol discussed herein will enable further drug discovery studies on the WalR response regulator protein to identify and characterize inhibitors, providing insight towards the development of novel antimicrobial compound.

Accuracy and Glycemic Efficacy of Continuous Glucose Monitors in Critically Ill COVID-19 Patients: A Retrospective Study.

BACKGROUND: Continuous glucose monitoring (CGM) is approved for insulin dosing decisions in the ambulatory setting, but not currently for inpatients. CGM has the capacity to reduce patient-provider contact in inpatients with coronavirus disease 2019 (COVID-19), thus potentially reducing in hospital virus transmission. However, there are sparse data on the accuracy and efficacy of CGM to titrate insulin doses in inpatients. METHODS: Under an emergency use protocol, CGM (Dexcom G6) was used alongside standard point-of-care (POC) glucose measurements in patients critically ill from complications of COVID-19 requiring intravenous (IV) insulin. Glycemic control during IV insulin therapy was retrospectively assessed comparing periods with and without adjunctive CGM use. Accuracy metrics were computed and Clarke Error Grid analysis performed comparing CGM glucose values with POC measurements. RESULTS: Twenty-four critically ill patients who met criteria for emergency use of CGM resulted in 47 333 CGM and 5677 POC glucose values. During IV insulin therapy, individuals' glycemic control improved when CGM was used (mean difference -30.7 mg/dL). Among 2194 matched CGM: POC glucose pairs, a high degree of concordance was observed with a mean absolute relative difference of 14.8% and 99.5% of CGM: POC pairs falling in Zones A and B of the Clarke Error Grid. CONCLUSIONS: Continuous glucose monitoring use in critically ill COVID-19 patients improved glycemic control during IV insulin therapy. Continuous glucose monitoring glucose data were highly concordant with POC glucose during IV insulin therapy in critically ill patients suggesting that CGM could substitute for POC measurements in inpatients thus reducing patient-provider contact and mitigating infection transmission.

Reversible parkinsonism post combined infection with COVID- 19 and typhoid

Objective: To describe a case of levo-dopa responsive parkinsonism secondary to combined COVID-19 and Enteric fever in a patient Background: The first link between viruses and parkinsonism comes from the possible relationship between lethargic encephalitis and the Spanish flu of 1918.In addition, other viruses, including West Nile virus, herpes viruses, influenza A virus, and human immunodeficiency virus (HIV), have been associated with parkinsonism Methods: A 31 years old presented with fever ,headache for 5 days followed by altered sensorium. At presentation he had neck rigidity ,was localizing to pain ,not fully oriented and not following verbal command but he had hypoxia and need nasal oxygen support.He had D-Dimer 12506,COVID-19 RTPCR positive and was treated with Remdesivir,ceftriaxone ,dexamethasone after which he had improvement in sensorium.At day 6 of illness he had generalized rigidity,bradykinesia with slow hypophonic speech and was needing support to sit and walk . A provisional diagnosis of infection related parkinsonism was considered and Cerebrospinal fluid study,MRI Brain and spine ,Blood culture were done .His Cerebrospinal fluid study has normal protein , glucose,cells, stains and culture and negative autoimmune and paraneoplastic plane . His urine culture,blood culture was positive for salmonella typhi and serum widal titre was 1:640.MRI Brain and spine does not show any new abnormalities except old trauma sequalae. He was treated with Levo-dopa carbidopa and titrated to a dose of 675 mg/day and had sustained improvement with levo-dopa carbidopa .There are 6 other case of COVID-19 associated parkinsonism in literature .There are also few case of typhoid associated case of parkinsonism described in literature . Our patient had combined infection of both COVID-19 and typhoid associated parkinsonism. Result(s): We report a case of Infection related parkinsonism secondary to combined COVID-19 plus typhoid infection Conclusion(s): Exploring the potential relationship of co-infection SARS-CoV-2 and Salmonella typhi infection with development of parkinsonism is essential because of the epidemiological implications,as well as to gain a better understanding of the pathophysiological aspects of these disorders.

Idiopathic anomalous congenital band causing small intestinal obstruction in a 5-month-old dog

A 5-month-old, intact male, yellow Labrador retriever was presented with a 24-hour history of anorexia and vomiting. Abdominal imaging revealed the presence of a mechanical obstruction in the jejunum and peritoneal effusion. Cytologic evaluation and culture of the effusion prior to surgery identified a suppurative exudate with bacteria consistent with septic peritonitis and suspected to be related to the intestinal lesion. An exploratory laparotomy was performed, and a segment of jejunum was circumferentially severely constricted by an off-white, fibrous band of tissue. Resection and anastomosis of the strangulated segment of jejunum and excision of the constricting band provided resolution of the clinical signs. The dog made a complete recovery. Histologic evaluation revealed the band to be composed of fibrovascular and smooth muscle tissue, consistent with an idiopathic anomalous congenital band. No other gastrointestinal lesions were observed, either grossly at surgery or histologically in the resected segment of intestine. To our knowledge, a similar structure has not been reported in the veterinary literature.Copyright © 2022 Canadian Veterinary Medical Association. All rights reserved.

New-onset neuromyelitis optica spectrum disorder in a patient with COVID-19 and chronic Hepatitis B co-infection

Background: Neurological autoimmune disorders are often triggered by bacterial and viral infections, with growing evidence supporting coronavirus disease 2019 (COVID-19) infection precipitation of these disorders. COVID-19 is already implicated in causing discrete para-infectious neurological syndromes: acute disseminated encephalomyelitis (ADEM), transverse myelitis, neuromyelitis optica spectrum disorders (NMOSD), Guillain-Barre syndrome (GBS), and is also associated with encephalopathy, acute cerebrovascular disease, neuromuscular disorders, and seizures. Case Presentation: We describe a case of a 43-year-old Asian woman with chronic Hepatitis B (HBV) co-infected acutely with COVID-19, presenting with urinary retention, bilateral blindness, thoracic sensory level, and quadriparesis. Extensive workup narrowed down her diagnosis as seronegative NMOSD. She had complete resolution of symptoms after treatment with concurrent plasma exchange (PLEX), high dose corticosteroids, and emtricitabine-tenofovir. Follow-up visit showed no seroconversion at 6 months and no relapses. Conclusion(s): Our literature review highlights the likely link between COVID-19 infection and the development of neurologic autoimmune diseases. Our literature review supports a virus-triggered immune-mediated process rather than neuro-invasion. Many viral illnesses have been linked to the development of NMOSD and anti-AQP4 antibody-related myelitis. Additionally, there is limited literature linking chronic HBV infection with the development of optic neuritis and speculation thatcross-reactivity between HBsAg and myelin antigens may lead to the development of demyelinating diseases in the CNS and PNS. We observed remarkable clinical improvement after treatment with alternating days of IV methylprednisolone and therapeutic PLEX.Copyright © 2022

Antiviral Activity of Interferon Alpha-2b and Taurine Combination Against SARS-CoV-2 in vitro.

Interferons (IFN) have antiviral activity against many viruses, including SARS-CoV-2. A combination of IFN-a2b and the antioxidant taurine is widely used in the Russian Federation, and its antiviral activity has not been studied before. The aim of this study was to determine the antiviral activity of interferon drugs, in combination with taurine and without it. The study included cytotoxicity and antiviral activity assays of IFN-a2b preparations, when stored according to the instructions at 2-8degreeC, and after 1 month storage at the temperature of 20-26degreeC in a pre-opened state. The combination of IFN alpha-2b with taurine has a higher antiviral activity compared to IFN alpha-2b mono-preparation by more than 25% at a <<low>> and 85% at a <<high>> multiplicity of infection. Selectivity index for combinations of IFN-a2b (50,000 IU/dose) + taurine (1 mg/ml) and IFN-a2b (10,000 IU/ml) + taurine (0.8 mg/ml) was more than 600 units, whereas for the IFN-a2b (10,000 IU/ml) it was 200 units. Antiviral activity does not change after one month at room temperature. The combination of interferon with taurine at high concentrations was less toxic than interferon. The results obtained demonstrate practicability of interferon alpha-2b and taurine combination use for treatment and prevention of COVID-19.Copyright © Team of Authors, 2022.

Haemodynamic (HD) evaluation of LIQ861 (treprostinil) inhalation powder for the treatment of pulmonary arterial hypertension (PAH)

Background: Treprostinil is a prostacyclin analogue which has been approved in the EU for intravenous (i.v.) and subcutaneous (SC) administration in patients with PAH. LIQ861 is a dry powder formulation of treprostinil which can be used for inhalation via a handheld device. Objectives and methods: LTI-201 was a multicentre, Phase 2, open-label, dose-escalation study to evaluate the HD dose-response and safety of LIQ861, followed by an open-label extension period. In "Part A" HD response was measured by right heart catheterization for 120 minutes after a single 26.5 or 53 mug dose of LIQ861. In "Part B" patients were titrated to symptomatic relief (<=159 mug QID) and were reassessed after 16 weeks using right heart catheterization and clinical assessments. Result(s): Fifteen PAH Patients (60 % female, mean age 56 +/- 14.3 years, mean pulmonary vascular resistance (PVR) 605+/-246 dynes/sec/cm-5) were included. In Part A HD measures (PVR and mean pulmonary arterial pressure) improved with a peak response after 15 minutes for both doses. The study was stopped early due to the COVID19 pandemic with only 6 patients completing Part B. At Week 16, these HD responses also improved and clinical assessments improved or remained stable for these patients. All doses of LIQ861 were generally well-tolerated with only one serious adverse event (short episode of hypoxia after inhalation). The most frequently reported adverse events were cough and throat irritation and most were assessed as mild in severity. Conclusion(s): LIQ861 was overall safe and well tolerated. An expected improvement in HD measures was seen with acute and chronic dosing.

The effect of COVID rehabilitation on fatigue and postexertional symptom exacerbation

Background: Fatigue is a common symptom after a COVID-19 infection. There is evidence to support COVID-19 rehabilitation (CoR) improving symptoms. However, there is concern that exercise therapies may increase postexertional symptom exacerbation (PESE). Aim(s): To determine the effect of 6 weeks of CoR on fatigue and symptoms of PESE. Method(s): 148 patients (55 +/- 13 y;56 [38%] male) completed 6 weeks of CoR including symptom-titrated exercise and education. Fatigue was assessed pre- and post-CoR using the Functional Assessment Chronic Illness TherapyFatigue questionnaire (FACIT). Patients with a FACIT score <30 were defined as having severe fatigue. PESE symptoms were assessed in a sub-group of patients (n=44) using a subscale of the DePaul Symptom Questionnaire (DSQ). A mean composite score was calculated for DSQ symptom questions. Result(s): FACIT score reduced pre- to post-CoR with a mean change of -5 +/- 9;p<0.01. The DSQ composite score improved by 20 +/- 21 (p<0.01, n=44). The magnitude of change in the DSQ composite score pre- to post-CoR was not different in those with (26 +/- 22) and without (19 +/- 21) severe fatigue (p=0.44). Conclusion(s): CoR has demonstrated improvements in fatigue and symptoms associated with PESE. The improvement in PESE symptoms pre- to post-CoR was similar in patients with and without severe fatigue, advocating the use of CoR in both cohorts.

Thermal Titration Molecular Dynamics (TTMD): Not Your Usual Post-Docking Refinement.

Molecular docking is one of the most widely used computational approaches in the field of rational drug design, thanks to its favorable balance between the rapidity of execution and the accuracy of provided results. Although very efficient in exploring the conformational degrees of freedom available to the ligand, docking programs can sometimes suffer from inaccurate scoring and ranking of generated poses. To address this issue, several post-docking filters and refinement protocols have been proposed throughout the years, including pharmacophore models and molecular dynamics simulations. In this work, we present the first application of Thermal Titration Molecular Dynamics (TTMD), a recently developed method for the qualitative estimation of protein-ligand unbinding kinetics, to the refinement of docking results. TTMD evaluates the conservation of the native binding mode throughout a series of molecular dynamics simulations performed at progressively increasing temperatures with a scoring function based on protein-ligand interaction fingerprints. The protocol was successfully applied to retrieve the native-like binding pose among a set of decoy poses of drug-like ligands generated on four different pharmaceutically relevant biological targets, including casein kinase 1δ, casein kinase 2, pyruvate dehydrogenase kinase 2, and SARS-CoV-2 main protease.

Thermodynamic analysis of the interactions between human ACE2 and Spike RBD of Betacoronaviruses (SARS-CoV-1 and SARS-CoV-2).

There are many scientific reports on the interaction of the SARS-CoV-2 virus S protein (and its RBD) with the human ACE2 receptor protein. However, there are no reliable data on how this interaction differs from the interaction of the receptor binding domain of SARS-CoV-1 with ACE2, in terms of binding strength and changes in reaction enthalpy and entropy. Our studies have revealed these differences as well as the impact of zinc ions on this interaction. Intriguingly, the binding affinity of both RBDs (of SARS-CoV-1 and of SARS-CoV-2) to the ACE2 receptor protein is almost identical; however, there are some differences in the entropic and enthalpic contributions to these interactions.

Development of SYBR green RT-qPCR assay for titrating bivalent live infectious bronchitis vaccines.

Infectious bronchitis (IB) is a highly contagious viral disease of chickens caused by IB virus (IBV) that can cause substantial economic losses in the poultry industry. IBV variant infections have been continuously reported since the initial description in the 1930s. QX-like IBVs are the predominant circulating genotype globally. A homologous QX vaccine has superior protection efficacy compared with that of other available vaccines, and the combination of Massachusetts (Mass)-like and QX-like strains is being used to combat QX-like IBV infections. Inoculation of embryonated chicken eggs is the standard method for the titration of IBV, and the titer is expressed as 50% egg infectious dose (EID50). However, this method cannot effectively distinguish or quantify different genotypic strains in a mixture of different viruses, especially in the absence of neutralizing monoclonal antibodies. In this study, quantitative real-time PCR (RT-qPCR) was applied using specific primers for the QX- and Mass-like strains to quantitate IBV infection and for comparison with the conventional virus titration quantitative method. A strong positive correlation was observed between RT-qPCR cycle threshold values and the different EID50 concentrations. This method was further used to titrate bivalent IB vaccines, and the amount of individual genotype virus was determined based on specific primers. Thus, this RT-qPCR assay may be used as a highly specific, sensitive, and rapid alternative to the EID50 assay for titering IBVs.

Assessing the Removal Efficiency of Murine Norovirus 1, Hepatitis A Virus, and Human Coronavirus 229E on Dish Surfaces Through General Wash Program of Household Dishwasher.

The performance of dishwashers in removing live viruses is an important informative value in practical applications. Since foodborne viruses are present in contaminated food surfaces and water environments. Insufficient washing of dishes typically makes a carrier of foodborne viruses. Dishwashers have shown excellent performance in removing bacterial pathogens, but very limited reports related to eliminate foodborne viruses on contaminated dish surfaces. Here, murine norovirus 1 (MNV-1), hepatitis A virus (HAV), and human coronavirus 229E (HCoV-229E) were experimentally inoculated on the dish surfaces (plate, rice bowl, and soup bowl). Plaque assay, 50% tissue culture infectious dose (TCID50), and real-time quantitative polymerase chain reaction (RT-qPCR) were conducted to determine their removal efficiency of them through the general wash program of household dishwashers. Using titration assay, MNV-1 and HAV were reduced by 7.44 and 6.57 log10 PFU/dish, and HCoV-229E was reduced by 6.43 log10 TCID50/dish through the general wash program, achieving a ≥ 99.999% reduction, respectively. Additionally, RT-qPCR results revealed that viral RNA of MNV-1 and HCoV-229E reduced 5.02 and 4.54 log10 genome copies/dish; in contrast, HAV was not detected on any dish surfaces. This study confirmed the performance of household dishwashers in removing pathogenic live viruses through the general wash program. However, residual viral RNA was not sufficiently removed. Further studies are needed to determine whether the viral RNA can be sufficiently removed using combination programs in household dishwashers.

Effect of Bolus Doses Prior to Uptitration of Fentanyl or Midazolam for Sedation

INTRODUCTION: Fentanyl and midazolam are highly lipophilic agents commonly used as continuous infusions for sedation. Based on the pharmacokinetics, a bolus dose could shorten the time to achieve steady state concentrations before being maintained with an increase in the continuous infusion. Upfront bolus dosing may avoid excessive uptitration to a maximum rate leading to drug accumulation, adverse reactions, and addition of other sedatives. The purpose of this study is to compare the efficacy and safety of bolus doses versus no bolus doses prior to up-titration of fentanyl and midazolam continuous infusions for sedation in mechanically ventilated adult patients in the medical intensive care unit (MICU). METHOD(S): This retrospective cohort study looked at adults receiving fentanyl or midazolam infusions for sedation for at least 24 hours admitted to the MICU at North Shore University Hospital from October 2021 to April 2022. The 2 cohorts are patients pre- and post-implementation of education on fentanyl and midazolam bolus doses. Patients were excluded if they were receiving concurrent neuromuscular blocking agents, had concurrent diagnosis of uncontrolled seizures, catastrophic stroke, intracranial hemorrhage, or COVID-19 as the primary diagnosis. The primary outcome of the study is duration of mechanical ventilation (MV). RESULT(S): Thirty-six patients were analyzed with 25 in the control group and 11 in the study group. More patients in the study group had history of leukemia (8% vs 45%, p=0.018) and a higher number of sedatives prior to study drug infusion (p=0.0383). There was no difference in the median duration of MV (6 vs 9 days, p=0.1179). The control group had a statistically significant lower sedation intensity score on days 1 and 2 of sedation that on average was 9.6 and 8.5 units lower, respectively. Outcomes including number of concomitant sedatives, in-hospital mortality and time to Richmond Agitation Sedation Scale (RASS) goal were not statistically significant. Adverse events were similar between groups. CONCLUSION(S): Low protocol adherence and small sample size limit the interpretation of results. Thus, larger studies would be required to assess if there is a difference in MV using the bolus vs no bolus dose titration. Next steps include further data collection and protocol reinforcement.