Angus Oli - Academia.edu (original) (raw)

Papers by Angus Oli

Clinical and Experimental Vaccine Research

Lassa fever is a zoonotic acute viral hemorrhagic disease caused by Lassa virus (LASV). There is ... more Lassa fever is a zoonotic acute viral hemorrhagic disease caused by Lassa virus (LASV). There is currently no licensed vaccine for the prevention of the disease. This study is aimed at discovering immunodominant epitopes from the envelope glycoprotein of the Lassa mammarenavirus and designing of a multi-epitope vaccine candidate (VC). Materials and Methods: The amino acid sequences of the envelope glycoprotein of 26 strains of LASV from five countries were selected. After evaluation for antigenicity, immunogenicity, allergenicity, and toxicity, immunodominant CD8, CD4, and linear B lymphocytes were also selected. The selected epitopes were modelled and a molecular docking with the appropriate major histocompatibility complex (MHC) proteins was performed. Using an adjuvant and linkers, a multi-epitope VC was designed. The VC was evaluated for its physicochemical and immunological properties and structurally refined, validated, and mutated (disulphide engineering). The complex formed by the VC and the toll-like receptor-4 receptor was subjected to molecular dynamic simulation (MDS) followed by in silico cloning in a plasmid vector. Results: A VC with 203 sequences, 22.13 kDa weight, isoelectric point of 9.85 (basic), instability index value of 27.62, aliphatic index of 68.87, and GRAVY value of-0.455 (hydrophilic) emerged. The VC is predicted to be non-allergenic with antigenicity, MHC I immunogenicity, and solubility upon overexpression values of 0.81, 2.04, and 0.86 respectively. The VC also has an estimated half-life greater than 10 hours in Escherichia coli and showed stability in all the parameters of MDS. Conclusion: The VC shows good promise in the prevention of Lassa fever but further tests are required to validate its safety and efficacy.

Additional file 3 : Fig. S3. Sex hormone concentrations.

Additional file 2 : Fig. S2. Serum urea, creatinine and uric acid concentrations.

Cureus

Graft tolerance is a pathophysiological condition heavily reliant on the dynamic interaction of t... more Graft tolerance is a pathophysiological condition heavily reliant on the dynamic interaction of the innate and adaptive immune systems. Genetic polymorphism determines immune responses to tissue/organ transplantation, and intricate humoral and cell-mediated mechanisms control these responses. In transplantation, the clinician's goal is to achieve a delicate equilibrium between the allogeneic immune response, undesired effects of the immunosuppressive drugs, and the existing morbidities that are potentially life-threatening. Transplant immunopathology involves sensitization, effector, and apoptosis phases which recruit and engages immunological cells like natural killer cells, lymphocytes, neutrophils, and monocytes. Similarly, these cells are involved in the transfer of normal or genetically engineered T cells. Advances in tissue transplantation would involve a profound knowledge of the molecular mechanisms that underpin the respective immunopathology involved and the design of precision medicines that are safe and effective.

Additional file 1 : Fig. S1. Serum lipids and glucose concentrations.

Life, 2022

COVID-19-infected patients require an intact immune system to suppress viral replication and prev... more COVID-19-infected patients require an intact immune system to suppress viral replication and prevent complications. However, the complications of SARS-CoV-2 infection that led to death were linked to the overproduction of proinflammatory cytokines known as cytokine storm syndrome. This article reported the various checkpoints targeted to manage the SARS-CoV-2-induced cytokine storm. The literature search was carried out using PubMed, Embase, MEDLINE, and China National Knowledge Infrastructure (CNKI) databases. Journal articles that discussed SARS-CoV-2 infection and cytokine storm were retrieved and appraised. Specific checkpoints identified in managing SARS-CoV-2 induced cytokine storm include a decrease in the level of Nod-Like Receptor 3 (NLRP3) inflammasome where drugs such as quercetin and anakinra were effective. Janus kinase-2 and signal transducer and activator of transcription-1 (JAK2/STAT1) signaling pathways were blocked by medicines such as tocilizumab, baricitinib, and...

Journal of Pharmaceutical Research International, 2021

Background: Native starches have some limitations such as the inability to withstand some process... more Background: Native starches have some limitations such as the inability to withstand some processing conditions, poor flow, packing and compressibility. Cross-linking of starch is one of the methods used to overcome these drawbacks to obtain derivatives with better and desirable properties. This study is aimed at assessing the utilisabilty of sucrose and formaldehyde cross-linked starches obtained from Zea mays, Triticum aestivum, and Oriza sativa as an excipient for paracetamol tablet formulation. The formulated tablets were evaluated for hardness, disintegration and drug release rate. Results: The formulated tablets had hardness in the range of 4.35 – 6.37 Kgf. Tablets produced from the native starches had significantly (P < 0.05) lower disintegration time compared to their respective cross-linked starches. The disintegration time of the tablets from the cross-linked starches was in the following order, modified rice starch tablets > modified maize starch tablets > modifi...

Advanced Pharmaceutical Bulletin, 2020

The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it... more The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form.

Open Journal of Medical Microbiology, 2020

Antimicrobial resistance refers to the ability of microorganisms to grow in the presence of an an... more Antimicrobial resistance refers to the ability of microorganisms to grow in the presence of an antimicrobial agent at a concentration that will normally kill or inhibit their growth. Antimicrobial resistance has become a major global threat making treatment of infections tougher especially with high cost of treatment in humans and animals. This study was done to determine the Multiple Antibiotic Resistant Index (MARI) of Gram-negative bacteria from bird droppings in two commercial poultries in Enugu. Forty (40) samples were collected from each of the poultries. Isolates were identified by standard microbiological methods. The isolates identified were Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Citrobacter spp, Proteus spp. and, Enterobacter spp. Antibiotic susceptibility testing was carried out using disc diffusion technique. The organisms were tested against pefloxacin, augmentin (amoxicillin and clavulanic acid), ceftazidime, streptomycin, ciprofloxacin, gentamycin, cephalothin, neomycin and ofloxacin. The result of the susceptibility test showed that Proteus spp had the highest resistance and MARI value of 0.5 and 1.0 respectively. The other MARI values were Escherichia coli (0.9), Klebsiella pneumonia (0.9), Pseudomonas aeruginosa (0.8), Citrobacter spp (0.8) and Enterobacter spp (0.7). These results suggest that bacterial organisms from poultry source can contribute significantly to the spread of multi-antibiotic resistant organisms. This could arise from the indiscriminate use of antibiotics in bird feeds in poultries.

Annals of Medical and Health Sciences Research, 2019

Introduction: Edible mushrooms have played prominent roles in improving the health of people for ... more Introduction: Edible mushrooms have played prominent roles in improving the health of people for centuries. Pleurotus ostreatus is an edible mushroom with history of medicinal uses. This study was designed to examine, in vitro and in vivo, the possibility of methanolic and hot aqueous extracts of the mushroom modulating Streptococcus pneumoniae infection. Methods: Bioactive constituents of the methanolic and hot aqueous extracts were determined quantitatively and qualitatively using standard methods. Isolation, identification and confirmation of Streptococcus pneumoniae in infected blood were done using standard protocols. The effect of the extract on cellular immune responses was assessed by phagocytosis evaluation and quantitative Nitroblue Tetrazolium Test. In vivo immunological response against Streptococcal infection was evaluated using the neutrophil adhesion test and Hemagglutinating antibody (HA) titre post infection in mice. Results: Methanol and aqueous extracts revealed t...

Asian Journal of Biomedical and Pharmaceutical Sciences, 2020

Background: Traditionally, diarrhoea in our locality has often been managed using herbs. Multi-dr... more Background: Traditionally, diarrhoea in our locality has often been managed using herbs. Multi-drugresistant organisms refer tomicrobes that areresistant to the effects of antimicrobial drugs to which they were previously susceptible at therapeutic range. Objectives: This study investigates the combined effects of Alchornea cordifolia and Pterocarpus santalinoides leaves extracts against selected multi-drug resistant diarrhoegenic bacteria. Methods: Fresh plant seeds were collected from the plants, shade-dried, pulverized and extracted with methanol in a Soxhlet apparatus. Antibacterial activities of these plants were investigated using agarwell diffusion assay. The MIC and FIC of the extracts against test isolates were determined using agar well diffusion method and checkerboard assay respectively. The bactericidal effects of the extracts against the isolates were evaluated using Time-Kill Assay. Results: MIC values of methanolic extracts against drug resistant strains of Salmonell...

Journal of basic and clinical pharmacy, 2017

Context: There is need for continuous monitoring and validation of pharmaceutical products (inclu... more Context: There is need for continuous monitoring and validation of pharmaceutical products (including vaccines) in circulation in every country. Vaccines must be maintained in cold-chain from the manufacturer to the end user. Aims: This study aims to validate the Oral Polio vaccines sourced from the Central Coldchain facilities and used for vaccination programmes in South-East, Nigeria. Settings and Design: The Study was an experimental in design and performed in laboratory. Methods and Materials: The immunogenicity test was done using Antibody Induction Method. This involved measuring the neutralizing antibodies in a control group (mice given Oral Polio vaccines stored at 37Â°C for 12 months) and test group (mice given Oral Polio vaccines sourced from South-east States) after 30 days using Enzyme-Linked-Immunosorbent-Assay technique. Statistical analysis used: One-Way Analysis of Variance (ANOVA), Dunnettâs Tests of Multiple Comparison and Bartlettâs test for equal variances we...

Journal of Inflammation Research, 2021

The outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2),... more The outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later named COVID-19 by the World Health Organization (WHO), was initiated at Wuhan, Hubei, China, and there was a rapid spread of novel SARS-CoV-2 and the disease COVID-19 in late 2019. The entire world is now experiencing the challenge of COVID-19 infection. However, still very few evidence-based treatment options are available for the prevention and treatment of COVID-19 disease. The present review aims to summarize the publicly available information to give a comprehensive yet balanced scientific overview of all the fat-soluble vitamins concerning their role in SARS-CoV-2 virus infection. The roles of different fat-soluble vitamins and micronutrients in combating SARS-CoV-2 infection have been recently explored in several studies. There are various hypotheses to suggest their use to minimize the severity of COVID-19 infection. These vitamins are pivotal in the maintenance and modulation of innate and cell-mediated, and antibody-mediated immune responses. The data reported in recent literature demonstrate that deficiency in one or more of these vitamins compromises the patients' immune response and makes them more vulnerable to viral infections and perhaps worse disease prognosis. Vitamins A, D, E, and K boost the body's defense mechanism against COVID-19 infection and specifically prevent its complications such as cytokine storm and other inflammatory processes, leading to increased morbidity and mortality overemphasis. However, more detailed randomized double-blind clinical pieces of evidence are required to define the use of these supplements in preventing or reducing the severity of the COVID-19 infection.

Recent Advances in Anti-Infective Drug Discovery, 2021

Aim: This study tries to find new antimicrobial agents using some Nigerian plants. Background: An... more Aim: This study tries to find new antimicrobial agents using some Nigerian plants. Background: Antimicrobial compounds from fungi endophytes have shown great promise in mitigating the threats of resistant pathogens. Objective: The study evaluated the in vitro antimicrobial property of secondary metabolites of endophytic fungi isolated from Newbouldia laevis and Cassia tora leaves. Methods: Ten endophytic fungi were isolated from the two plants’ leaves and later fermented on local rice for 21 days. Thereafter, their secondary metabolites were extracted using ethyl acetate. The antibacterial activity of the extracts on the test organisms were determined using agar diffusion and agar dilution methods, while the bioactive constituents were identified using high performance liquid chromatography coupled to diode array detector. Results: Nine of the crude extracts (NL1, NL3, NL6, NL10, NL12, CT2, CT7, CT9 and CT10) of the fungi isolates inhibited at least one of the microorganisms studied...

Current Drug Targets, 2020

The global incidence of cancer is on the increase and researchers are prospecting for specific an... more The global incidence of cancer is on the increase and researchers are prospecting for specific and non-selective therapies derived from the immune system. The killer activating receptors of NK cells are known to be involved in immunosurveillance against tumor and virally-infected cells. These receptors belong to two main categories, namely the immunoglobulin like and C-lectin like families. Though they have different signal pathways, all the killer activating receptors have similar effector functions which include direct cytotoxicity and the release of inflammatory cytokines such as IFN-gamma and TNF-alpha. To transduce signals that exceed the activation threshold for cytotoxicity, most of these receptors require synergistic effort. This review profiles 21 receptors: 13 immunoglobulin-like, 5 lectin-like, and 3 others. It critically explores their structural uniqueness, role in disease, respective transduction signal pathways and their status as current and prospective targets for c...

Medical Sciences, 2019

Extended-spectrum β-lactamase (ESBL)-producing organisms have become a serious challenge in healt... more Extended-spectrum β-lactamase (ESBL)-producing organisms have become a serious challenge in healthcare delivery globally. The prevalence of ESBL carriage in healthy and sick children in Enugu, Nigeria, was bacteriologically investigated in this study. Four hundred and twenty-two biological samples (mid-stream urine and feces) were bacteriologically analyzed. The isolates were screened for ESBL production using Clinical and Laboratory Standards Institute (CLSI) breakpoints. The suspected ESBL producers were confirmed using double disc synergy test method. Out of the 162 isolates screened, 32 (19.8%) were confirmed as ESBL positive, with a prevalence of 25.32% among sick children in Enugu State University Teaching Hospital (ESUTH), Parklane, Enugu and 13.89% in apparently healthy children in a community setting. Klebsiella spp. and Escherichia coli had the highest prevalence of 34.6% and 28.6%, respectively; Citrobacter spp. and Enterobacter spp. were 18.2% and 16.7%, respectively. Th...

Journal of pharmacological and toxicological methods, Jan 26, 2016

The aim of this study was to investigate the suitability of rhodamine-123, rhodamine-6G and rhoda... more The aim of this study was to investigate the suitability of rhodamine-123, rhodamine-6G and rhodamine B as non-radioactive probes for characterizing organic cation transporters in respiratory cells. Fluorescent characteristics of the compounds were validated under standard in vitro drug transport conditions (buffers, pH, and light). Uptake/transport kinetics and intracellular accumulation of the compounds were investigated. Uptake/transport mechanisms were investigated by comparing the effect of pH, temperature, concentration, polarity, OCTs/OCTNs inhibitors/substrates, and metabolic inhibitors on the cationic dyes uptake in Calu-3 cells. Fluorescence stability and intensity of the compounds were altered by buffer composition, light, and pH. Uptake of the dyes was concentration-, temperature- and pH-dependent. OCTs/OCTNs inhibitors significantly reduced intracellular accumulation of the compounds. Whereas rhodamine-B uptake was sodium-dependent, pH had no effect on rhodamine-123 and...

Trials in Vaccinology, 2016

Background: The current and general safety control tests for vaccines have been the use several a... more Background: The current and general safety control tests for vaccines have been the use several animal tests. Vaccine is considered safe if it does not cause weight loss or death in laboratory animals at human dose, does not promote leukocytosis by a factor P10 and showed a Leukopenic toxicity value P80% of the Leukopenic toxicity of the control. The study sets to determine the safety of routine immunization vaccines from Anambra, Ebonyi and Enugu states of Nigeria and indirectly evaluate the efficiency of cold-chain facilities. Method: The study was designed to check the safety of the routine immunization vaccines to the hematopoietic system of mice and mice body weight changes after immunization. Results: Animal body weight changes test showed that the mice immunized with the vaccines increased in weight at days 3 and 7 post-immunization and exceeded 60% weight gain at day 7 post-immunization. None of the mice died during the observation period. Hematopoietic system toxicity tests showed that the vaccines are non-toxic. Conclusion: The vaccines were generally safe and non-toxic. The cold-chain systems in the States studied were efficient and had not compromised the safety of the vaccines.

African journal of pharmacy and pharmacology

The aim of this study was to evaluate the anti-microbial activities of some liquid herbal anti-in... more The aim of this study was to evaluate the anti-microbial activities of some liquid herbal anti-infectives manufactured and marketed in SouthEastern Nigeria and determine the extent of their microbial contamination. Twenty samples were randomly collected from herbal shops in the five states that make up the SouthEast Nigeria. Antibacterial activities of the herbal preparations were evaluated using agar-well-diffusion method. The samples that showed significant antibacterial activity against the test organisms were further subjected to cell killing rate test. Maximum inhibitory dilutions of the active compounds were obtained and their in vitro anti-infective activity against multidrug resistance Staphylococcus aureus (MRSA) and Extended Spectrum β-Lactamase (ESBL) organisms were evaluated also. Eight (40%) of the product showed some antibacterial activity and none have antifungal activity against the test fungi. Kill kinetic experiment showed that some products have some activity agai...

Journal of Drug Targeting, 2012

Background: To fully exploit organic cation transporters for targeted drug delivery in the lung, ... more Background: To fully exploit organic cation transporters for targeted drug delivery in the lung, the use of a readily available and well-characterized tissue culture model and cheap easily detectable substrates is indispensable. Objectives: To investigate the suitability of Calu-3 as tissue model for characterizing organic cation permeation across the bronchial cells using a fluorescent dye, 4-(4-(Dimethylamino)styryl)-N-methylpyridinium iodide (4-DI-1-ASP). Methods: Substrate uptake, inhibition, and transport were performed to establish active transport mechanism. Organic cation transporter expression was determined with quantitative polymerase chain reaction (qPCR), immune-histochemistry, and fluorescent microscopy. Results: 4-Di-1-ASP uptake in Calu-3 cells was concentration (K m = 2.7 ± 0.3 mM, V max = 4.6 ± 2.6 nmol/µg protein/30 min), temperature (uptake at 37°C>>4°C), and pH dependent (higher uptake at pH ≥ 7). L-carnitine, verapamil, and corticosterone significantly inhibited its uptake with IC 50 of 28.2, 0.81, and 0.12 mM, respectively. Transport of the dye across the cells was polarized (AP→BL transport was 2.5-fold > BL→AP), saturable (Km = 43.9 ± 3.2) (µM; Vmax =0.0228± nmol/cm 2 /sec) and reduced 3-fold by metabolic inhibition. The expression pattern of the organic cation transporters (OCT) and carnitine/organic cation transporter (OCTN) isoforms was: OCT1<<OCT3 <OCTN1<OCTN2; OCT2 was not detected. Conclusions: Based on qPCR, immunohistochemistry, uptake and transport data, the Calu-3 cells can be used as a model for not only studying strategies for optimizing the effect of inhaled organic cations, but also for cross-validating newly-developed respiratory cell lines.