23 research outputs found

    Determination of Rheumatoid Factor in Suspected Rheumatoid Arthritis Patients Attending Selected Hospitals in Zaria, Nigeria

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    The study was carried out to provide information on RF among RA especially in the Northern part of Nigeria is relatively scarce. As such, rheumatoid factor levels in blood could serve as a predictive index for the onset of Rheumatoid arthritis. A total of 182 sera samples were analyse for the presence of IgM rheumatoid factor by ELISA. Seventeen (17) were found to be positive and 165 negative giving a prevalence of 9.3% and 90.7% respectively. The age range of 50 and above had the highest RF positive cases of 4.9%. This is followed by the eighteen (18) to thirty (30) age range. The association was not significant at p-value of 0.05. Similarly, the relationship between RF and gender showed that 5.5% (n=101) of females were positive while than 3.8% (n=81) of males were positive. The association was not significant. The highest participants had tertiary level of education which has a RF prevalence of 4.4%. Most of the participants that tested positive for RF were married (8.2%). There was no significant association between positivity for RF and level of education as well as marital status. There was however no statistical significant association between RF and the signs and symptoms (stiffness of joints, swelling around the joints, general fatigue, muscle pains, fever 13 and joint pains). Out of the 29 patients with history investigated for RA, 4 (2.2%) were positive for RF. Among the participants that smoke cigarette (n=4), none was RF positive. Both factors did not show significant association at a p-value of 0.05. The information in this study would serve as a predictive index for the onset of Rheumatoid arthritis. Keywords: Rheumatoid Arthritis, Rheumatoid Factor, Auto-immune disease, synovial inflammatio

    Effect of Vernonia amygdalina Ethanolic Root Extract on the Hepato- and Nephro-Protective Properties of Albino Rats (Rattus novergicus)

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    The hepato- and nephro-protective potentials of Vernonia amygdalina ethanolic root extract was evaluated for 14 days using standard bioassay in 45 normal male albino rats. The rats were divided into four treatment groups I – IV and a control group V. Groups I – IV were given 100mg.kg-1, 200mg.kg-1, 400mg.kg-1 and 600mg.kg-1 body weight, respectively while the control (group V) was given equal volume of feed and water. The extracts were administered orally to the animals for 14 days. Blood samples were collected using the ocular puncture method before and weekly after administration to evaluate the extracts’ effects on aspartate transaminase (AST), acid phosphatase (ACP), alanine transaminase (ALT), alkaline phosphatase (ALP), bilirubin, creatinine and blood urea nitrogen (BUN) levels. The mean serum levels of the liver marker enzymes AST, ACP, ALT, ALP, total bilirubin and direct bilirubin ranged from 10.00±0.53 to 11.44±0.44, 31.29±0.64 to 33.14±0.56, 27.22±0.94 to 29.67±0.37 and 37.83±0.59 to 40.57±1.02, 3.42±0.08 to 3.61±0.07 and 2.06±0.11 to 2.51±0.05 respectively. The mean levels of the nephrotic enzymes, creatinine and BUN also ranged from 39.87±1.79 to 43.04±1.57 and 6.62±0.21 to 15.98±0.17 accordingly. Although no significant difference (p>0.05) was observed in the serum levels of the liver marker enzymes and creatinine when compared with the control, a dose and duration dependent significant increase (p<0.05) occurred in the BUN level. This tends to suggest that the ethanolic root extract of Vernonia amygdalina on a short term basis has some hepato-protective property while its nephro-protective ability is still doubtful. Keywords: Vernonia amygdalina, Ethanolic root extract, Liver maker enzymes, Nephrotic enzymes, Albino rat

    Immunoinformatics assisted design of a multi-epitope kit for detecting <i>Cronobacter sakazakii</i> in powdered infant formula

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    Objectives: Cronobacter sakazakii, formerly Enterobacter sakazakii, is an emerging ubiquitous and opportunistic foodborne pathogen with a high mortality rate. It has been implicated in cases of meningitis, septicaemia, and necrotizing enterocolitis among infants worldwide in association with powdered infant formula (PIF). This study was an insilico designed peptide base kit framework, using immunoinformatic techniques for quick detection of C. sakazakii in PIF. Materials and Methods: In the present study, a peptide-based kit was designed with a bioinformatic technique to rapidly identify C. sakazakii in PIF using flhE, secY, and bcsC, which are genes responsible for its biofilm formation, as target genes. The antigenicity, membrane topology, and the presence of signal peptides of the target genes were analysed using VaxiJen, DeepTMHMM, and SignalP servers. To provide stability and flexibility to the multiple-epitope construct, the linear B cells and helper T cells (IL-4 (interleukin 4) and IL-10 (interleukin 10) inducing epitopes) were linked with a GSGSG linker followed by the addition of protein disulphide bonds. To ascertain specificity, the multi-epitope construct was molecularly docked against genes from sources other than PIF, like alfalfa, and the environment, with PIF being the highest: –328.48. Finally, the codons were modified using the pET28a(+) vector, and the resultant multi-epitope construct was successfully cloned in silico. Results: The final construct had a length of 486 bp, an instability index of 23.26, a theoretical pI of 9.34, a molecular weight of 16.5 kDa, and a Z-score of –3.41. Conclusions: The multi-epitope peptide construct could be a conceptual framework for creating a C. sakazakii peptide-based detection kit, which has the potential to provide fast and efficient detection. However, there is a need for additional validation through the in vitro and in vivo techniques

    Bioinformatics, Computational Informatics, and Modeling Approaches to the Design of mRNA COVID-19 Vaccine Candidates.

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    This article is devoted to applying bioinformatics and immunoinformatics approaches for the development of a multi-epitope mRNA vaccine against the spike glycoproteins of circulating SARS-CoV-2 variants in selected African countries. The study’s relevance is dictated by the fact that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began its global threat at the end of 2019 and since then has had a devastating impact on the whole world. Measures to reduce threats from the pandemic include social restrictions, restrictions on international travel, and vaccine development. In most cases, vaccine development depends on the spike glycoprotein, which serves as a medium for its entry into host cells. Although several variants of SARS-CoV-2 have emerged from mutations crossing continental boundaries, about 6000 delta variants have been reported along the coast of more than 20 countries in Africa, with South Africa accounting for the highest percentage. This also applies to the omicron variant of the SARS-CoV-2 virus in South Africa. The authors suggest that bioinformatics and immunoinformatics approaches be used to develop a multi-epitope mRNA vaccine against the spike glycoproteins of circulating SARS-CoV-2 variants in selected African countries. Various immunoinformatics tools have been used to predict T- and B-lymphocyte epitopes. The epitopes were further subjected to multiple evaluations to select epitopes that could elicit a sustained immunological response. The candidate vaccine consisted of seven epitopes, a highly immunogenic adjuvant, an MHC I-targeting domain (MITD), a signal peptide, and linkers. The molecular weight (MW) was predicted to be 223.1 kDa, well above the acceptable threshold of 110 kDa on an excellent vaccine candidate. In addition, the results showed that the candidate vaccine was antigenic, non-allergenic, non-toxic, thermostable, and hydrophilic. The vaccine candidate has good population coverage, with the highest range in East Africa (80.44%) followed by South Africa (77.23%). West Africa and North Africa have 76.65% and 76.13%, respectively, while Central Africa (75.64%) has minimal coverage. Among seven epitopes, no mutations were observed in 100 randomly selected SARS-CoV-2 spike glycoproteins in the study area. Evaluation of the secondary structure of the vaccine constructs revealed a stabilized structure showing 36.44% alpha-helices, 20.45% drawn filaments, and 33.38% random helices. Molecular docking of the TLR4 vaccine showed that the simulated vaccine has a high binding affinity for TLR-4, reflecting its ability to stimulate the innate and adaptive immune response

    Delayed mucosal anti-viral responses despite robust peripheral inflammation in fatal COVID-19

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    Background While inflammatory and immune responses to SARS-CoV-2 infection in peripheral blood are extensively described, responses at the upper respiratory mucosal site of initial infection are relatively poorly defined. We sought to identify mucosal cytokine/chemokine signatures that distinguished COVID-19 severity categories, and relate these to disease progression and peripheral inflammation. Methods We measured 35 cytokines and chemokines in nasal samples from 274 patients hospitalised with COVID-19. Analysis considered the timing of sampling during disease, as either the early (0-5 days post-symptom onset) or late (6-20 days post-symptom onset). Results Patients that survived severe COVID-19 showed IFN-dominated mucosal immune responses (IFN-γ, CXCL10 and CXCL13) early in infection. These early mucosal responses were absent in patients that would progress to fatal disease despite equivalent SARS-CoV-2 viral load. Mucosal inflammation in later disease was dominated by IL-2, IL-10, IFN-γ, and IL-12p70, which scaled with severity but did not differentiate patients who would survive or succumb to disease. Cytokines and chemokines in the mucosa showed distinctions from responses evident in the peripheral blood, particularly during fatal disease. Conclusions Defective early mucosal anti-viral responses anticipate fatal COVID-19 but are not associated with viral load. Early mucosal immune responses may define the trajectory of severe COVID-19

    The P323L substitution in the SARS-CoV-2 polymerase (NSP12) confers a selective advantage during infection

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    Background The mutational landscape of SARS-CoV-2 varies at the dominant viral genome sequence and minor genomic variant population. During the COVID-19 pandemic, an early substitution in the genome was the D614G change in the spike protein, associated with an increase in transmissibility. Genomes with D614G are accompanied by a P323L substitution in the viral polymerase (NSP12). However, P323L is not thought to be under strong selective pressure. Results Investigation of P323L/D614G substitutions in the population shows rapid emergence during the containment phase and early surge phase during the first wave. These substitutions emerge from minor genomic variants which become dominant viral genome sequence. This is investigated in vivo and in vitro using SARS-CoV-2 with P323 and D614 in the dominant genome sequence and L323 and G614 in the minor variant population. During infection, there is rapid selection of L323 into the dominant viral genome sequence but not G614. Reverse genetics is used to create two viruses (either P323 or L323) with the same genetic background. L323 shows greater abundance of viral RNA and proteins and a smaller plaque morphology than P323. Conclusions These data suggest that P323L is an important contribution in the emergence of variants with transmission advantages. Sequence analysis of viral populations suggests it may be possible to predict the emergence of a new variant based on tracking the frequency of minor variant genomes. The ability to predict an emerging variant of SARS-CoV-2 in the global landscape may aid in the evaluation of medical countermeasures and non-pharmaceutical interventions

    A prenylated dsRNA sensor protects against severe COVID-19

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    Inherited genetic factors can influence the severity of COVID-19, but the molecular explanation underpinning a genetic association is often unclear. Intracellular antiviral defenses can inhibit the replication of viruses and reduce disease severity. To better understand the antiviral defenses relevant to COVID-19, we used interferon-stimulated gene (ISG) expression screening to reveal that OAS1, through RNase L, potently inhibits SARS-CoV-2. We show that a common splice-acceptor SNP (Rs10774671) governs whether people express prenylated OAS1 isoforms that are membrane-associated and sense specific regions of SARS-CoV-2 RNAs, or only express cytosolic, nonprenylated OAS1 that does not efficiently detect SARS-CoV-2. Importantly, in hospitalized patients, expression of prenylated OAS1 was associated with protection from severe COVID-19, suggesting this antiviral defense is a major component of a protective antiviral response

    Genomic investigations of unexplained acute hepatitis in children

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    Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children

    Eco-physiological adaptation of the land snail Achatina achatina (Gastropoda: Pulmonata) in tropical agro-ecosystem

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    The survival of land snails in an adverse environmental condition depends on the integral physiological, morphological and behavioural adaptations. These adaptations are essential in understanding the species-specific habitat requirements and in predicting their environmental responses. In this study, the monthly and the periodic patterns of eco-physiological adaptation of land snail, Achatina achatina in Nsukka tropical agro-ecosystem were assessed from December 2012 to July 2013. Standard methods were employed in sampling the land snail and determination of the water content, biochemical fuel reserves and enzyme concentrations of the samples. The present results showed that lipids were high at the beginning of aestivation and depleted as the aestivation progressed. Glycogen was significantly low throughout the aestivation months (December–March) and increased in the active months (April–July). Protein content recorded a definite pattern all through the months studied. Catabolism of lactate and a decrease in activity of LDH during aestivation and substantial increase upon activation were observed. Data showed that transaminase and aspartate enzymes depleted during the aestivation months indicating that the snails may have developed potential cell injury due to oxidative stress and thermal heat. A disassociation between the physiological responses and climatic data was recorded. The physiological adaptation of A. achatina ensures regular adjustment under extreme conditions and compensates for its metabolic regulation in the tropics. It is concluded that survival of A. achatina is not environmentally predicted; rather it depends on the species-specific inherent process in predicting responses for survival
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