Diagnostic efficacy of monoclonal antibody based sandwich enzyme linked immunosorbent assay (ELISA) for detection of Fasciola gigantica excretory/secretory antigens in both serum and stool

<p>Abstract</p> <p>Background</p> <p>This research was carried out to develop a reliable monoclonal antibody (MoAb)-based sandwich enzyme linked immunosorbent assay (ELISA) for the diagnosis of active <it>Fasciola gigantica </it>infection in both serum and stool for comparative purposes.</p> <p>Methods</p> <p>From a panel of MoAbs raised against <it>F. gigantica </it>excretory/secretory antigens (ES Ags), a pair (12B/11D/3F and 10A/9D/10G) was chosen due to its high reactivity and strict specificity to <it>F. gigantica </it>antigen by indirect ELISA.</p> <p>Results</p> <p>The two MoAbs were of the IgG₁and IgG_2asubclasses, respectively. Using SDS-PAGE and EITB, the selected MoAbs recognized 83, 64, 45 and 26 kDa bands of ES Ags. The lower detection limit of ELISA assay was 3 ng/ml. In stool, the sensitivity, specificity and diagnostic efficacy of ELISA was 96%, 98.2 and 97.1%; while in serum they were 94%, 94.6% and 94.3%, respectively. Moreover, a positive correlation was found between ova count in stool of <it>F. gigantica </it>infected patients and the OD readings of ELISA in both stool and serum samples (<it>r </it>= 0.730, p < 0.01 and r = 0.608; p < 0.01, respectively).</p> <p>Conclusions</p> <p>These data showed that the use of MoAb-based sandwich ELISA for the detection of <it>F. gigantica </it>coproantigens in stool specimens was superior to serum samples; it provides a highly efficient, non-invasive technique for the diagnosis of active <it>F. gigantica </it>infection.</p

A unique view of SARS-COV-2 through the lens of ORF8 protein

Immune evasion is one of the unique characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) attributed to its ORF8 protein. This protein modulates the adaptive host immunity through down-regulation of MHC-1 (Major Histocompatibility Complex) molecules and innate immune responses by surpassing the host\u27s interferon-mediated antiviral response. To understand the host\u27s immune perspective in reference to the ORF8 protein, a comprehensive study of the ORF8 protein and mutations possessed by it have been performed. Chemical and structural properties of ORF8 proteins from different hosts, such as human, bat, and pangolin, suggest that the ORF8 of SARS-CoV-2 is much closer to ORF8 of Bat RaTG13-CoV than to that of Pangolin-CoV. Eighty-seven mutations across unique variants of ORF8 in SARS-CoV-2 can be grouped into four classes based on their predicted effects (Hussain et al., 2021) [1]. Based on the geo-locations and timescale of sample collection, a possible flow of mutations was built. Furthermore, conclusive flows of amalgamation of mutations were found upon sequence similarity analyses and consideration of the amino acid conservation phylogenies. Therefore, this study seeks to highlight the uniqueness of the rapidly evolving SARS-CoV-2 through the ORF8

Late response to rituximab in a dialysis patient with severe lupus nephritis

Although recently completed controlled trials failed to demonstrate a significant effect of rituximab on the clinical outcome in non-renal and renal lupus, there is growing evidence from case reports and open-label trials that the use of this medication is successful in certain subgroups of patients including refractory cases and helps in reducing the dose of steroids. We present a 26-year-old female who failed to respond to a long-course treatment with prednisolone, cyclophosphamide, mycophenolate mofetil and azathioprine and who went on to develop end-stage renal disease requiring commencement of regular maintenance hemodialysis. Ten days before starting dialysis, she was given rituximab, and a second dose was given 17 days after starting dialysis. After 7 months on dialysis, the patient began to regain kidney function and is now off dialysis for 11 months. To the best of our knowledge, this is the first case report of a lupus patient on dialysis treated with rituximab in whom dialysis could be stopped and who remained off this therapy up till now, after an observation period of 1 year

Daily versus post-dialysis administration of calcimimetics for the treatment of secondary hyperparathyroidism in haemodialysis patients: an interventional, multi-centre study [article retracted]

This article has been retracted.The retraction notice was published on 06 May 2020: Retraction notice: Daily versus post-dialysis administration of calcimimetics for the treatment of secondary hyperparathyroidism in haemodialysis patients: an interventional, multi-centre study. Afr J Nephrol. 2020; 2391):85

Troponin-I is not falsely elevated in asymptomatic dialysis patients

Dialysis patients with troponin-I levels above the cut-off value diagnostic for acute myocardial event (AME) are sometimes labeled as having "renal cause" of elevated troponin-I. Patients with troponin-I levels above 0.0 ng/mL, but below the cut-off level for an AME, are reported to have increased risk for coronary heart disease and mortality. Single pre-dialysis blood samples were taken from 150 asymptomatic dialysis patients (on hemo- or peritoneal dialysis) for troponin-I, cardiac enzymes, C-reactive protein (CRP) and lipid parameters. Troponin-I was measured by a chemiluminescent microparticle immunoassay (CMIA), of which the cut-off value for AME was set at ≥0.4 ng/mL. Patients with troponin-I levels of 0.0 ng/mL, and those with levels between 0.1 and 0.3 ng/mL, were compared regarding their cardiovascular risk profile. None of the patients had troponin-I concentrations above the cut-off level diagnostic for an AME, with 85.3% of the patients having levels of 0.0 ng/mL. While there was no difference in the "traditional" risk factors such as age, body mass index, prevalence of diabetes mellitus, hypertension, total cholesterol and low-density lipoprotein cholesterol between patients with troponin-I levels of 0.1-0.3 ng/mL and those with levels of 0.0 ng/mL, CRP concentrations were higher in the former. In peritoneal dialysis patients, the weekly Kt/V was lower in the patients with troponin levels between 0.1 and 0.3 ng/mL. The findings should add strong support in settling the debate of whether or not in patients on dialysis, falsely elevated levels of troponin-I "commonly" occur. An increased level of CRP and lower Kt/V might add to the cardiovascular risk in patients with troponin-levels between 0.1 and 0.3 ng/mL

Comprehensive Virtual Screening of the Antiviral Potentialities of Marine Polycyclic Guanidine Alkaloids against SARS-CoV-2 (Covid-19)

A comprehensive in silico binding affinity of fifteen guanidine alkaloids against five different proteins of SARS-CoV-2 has been investigated. The investigated proteins are COVID-19 main protease (Mpro) (PDB ID: 6lu7), spike glycoprotein (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17), and non-structural protein (nsp10) (PDB ID: 6W4H). The binding energies for all tested compounds indicated promising binding affinities. A noticeable superiority for the pentacyclic alkaloids particularly, crambescidin 786 (5) and crambescidin 826 (13) have been observed. Compound 5 exhibited very good binding affinities against Mpro (ΔG = -8.05 kcal/mol), nucleocapsid phosphoprotein (ΔG = -6.49 kcal/mol), and nsp10 (ΔG = -9.06 kcal/mol). Compound 13 showed promising binding affinities against Mpro (ΔG = -7.99 kcal/mol), spike glycoproteins (ΔG = -6.95 kcal/mol), and nucleocapsid phosphoprotein (ΔG = -8.01 kcal/mol). Such promising activities might be attributed to the long ω-fatty acid chain, which may play a vital role in binding within the active sites. The ADMET studies were carried out in silico for the 15 compounds, all examined compounds (except compounds 8 and 15) have low or very low BBB penetration levels. Compounds 1, 5, 6, 9, 12 and 13 showed optimal range levels of ADMET aqueous solubility. Compounds 1, 2, 3, 8, and 15 were predicted to have good intestinal absorption levels, while compounds 4, 7, 9, 10, and 14 showed moderate absorption levels. All examined alkaloids (except the bicyclic compound 8) were predicted not to be inhibitors of CYP2D6, non-hepatotoxic, and bind plasma protein with a percentage less than 90%. The toxicity of the tested compounds was screened in silico against five models (FDA rodent carcinogenicity, carcinogenic potency TD50, rat maximum tolerated dose, rat oral LD50 and rat chronic LOAEL). All compounds showed expected low toxicity against the tested models. </p

Investigating the Structure-Activity Relationship of Marine Polycyclic Batzelladine Alkaloids as Promising Inhibitors for SARS-CoV-2 Main Protease (Mpro)

Over a span of two years ago, since the emergence of the first case of the novel coronavirus (SARS-CoV-2) in China, the pandemic has crossed borders causing serious health emergencies, immense economic crisis and impacting the daily life worldwide. Despite the discovery of numerous forms of precautionary vaccines along with other recently approved orally available drugs, yet effective antiviral therapeutics are necessarily needed to hunt this virus and its variants. Historically, naturally occurring chemicals have always been considered the primary source of beneficial medications. Considering the SARS-CoV-2 main protease (Mpro) as the duplicate key element of the viral cycle and its main target, in this paper, an extensive virtual screening for a focused chemical library of 15 batzelladine marine alkaloids, was virtually examined against SARS-CoV-2 main protease (Mpro) using an integrated set of modern computational tools including molecular docking (MDock), molecule dynamic (MD) simulations and structure-activity relationships (SARs) as well. The molecular docking predictions had disclosed four promising compounds including batzelladines H-I (8-9) and batzelladines F-G (6-7), respectively according to their prominent ligand-protein energy scores and relevant binding affinities with the (Mpro) pocket residues. The best two chemical hits, batzelladines H-I (8-9) were further investigated thermodynamically though studying their MD simulations at 100 ns, where they showed excellent stability within the accommodated (Mpro) pocket. Moreover, SARs studies imply the crucial roles of the fused tricyclic guanidinic moieties, its degree of unsaturation, position of the N-OH functionality and the length of the side chain as a spacer linking between two active sites, which disclosed fundamental structural and pharmacophoric features for efficient protein-ligand interaction. Such interesting findings are greatly highlighting further in vitro/vivo examinations regarding those marine natural products (MNPs) and their synthetic equivalents as promising antivirals

Comprehensive Virtual Screening of the Antiviral Potentialities of Marine Polycyclic Guanidine Alkaloids against SARS-CoV-2 (COVID-19)

The huge global expansion of the COVID-19 pandemic caused by the novel SARS-corona virus-2 is an extraordinary public health emergency. The unavailability of specific treatment against SARS-CoV-2 infection necessitates the focus of all scientists in this direction. The reported antiviral activities of guanidine alkaloids encouraged us to run a comprehensive in silico binding affinity of fifteen guanidine alkaloids against five different proteins of SARS-CoV-2, which we investigated. The investigated proteins are COVID-19 main protease (Mpro) (PDB ID: 6lu7), spike glycoprotein (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17), and a non-structural protein (nsp10) (PDB ID: 6W4H). The binding energies for all tested compounds indicated promising binding affinities. A noticeable superiority for the pentacyclic alkaloids particularly, crambescidin 786 (5) and crambescidin 826 (13) has been observed. Compound 5 exhibited very good binding affinities against Mpro (ΔG = −8.05 kcal/mol), nucleocapsid phosphoprotein (ΔG = −6.49 kcal/mol), and nsp10 (ΔG = −9.06 kcal/mol). Compound 13 showed promising binding affinities against Mpro (ΔG = −7.99 kcal/mol), spike glycoproteins (ΔG = −6.95 kcal/mol), and nucleocapsid phosphoprotein (ΔG = −8.01 kcal/mol). Such promising activities might be attributed to the long ω-fatty acid chain, which may play a vital role in binding within the active sites. The correlation of c Log P with free binding energies has been calculated. Furthermore, the SAR of the active compounds has been clarified. The Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) studies were carried out in silico for the 15 compounds; most examined compounds showed optimal to good range levels of ADMET aqueous solubility, intestinal absorption and being unable to pass blood brain barrier (BBB), non-inhibitors of CYP2D6, non-hepatotoxic, and bind plasma protein with a percentage less than 90%. The toxicity of the tested compounds was screened in silico against five models (FDA rodent carcinogenicity, carcinogenic potency TD50, rat maximum tolerated dose, rat oral LD50, and rat chronic lowest observed adverse effect level (LOAEL)). All compounds showed expected low toxicity against the tested models. Molecular dynamic (MD) simulations were also carried out to confirm the stable binding interactions of the most promising compounds, 5 and 13, with their targets. In conclusion, the examined 15 alkaloids specially 5 and 13 showed promising docking, ADMET, toxicity and MD results which open the door for further investigations for them against SARS-CoV-2