The Potential of Amaranthus caudatus as a Phytoremediating Agent for Lead

The potential of Amaranthus caudatus as a phytoremediating agent was studied, using lead spiked soil to grow the plants. The effect of the concentration of lead on plant growth was studied. The main aim of the study was to assess the accumulation of lead (Pb) in different compartments of the plant. The plants were grown in soils treated with solutions corresponding to 25, 50, 75 and 100 ppm of Pb. The plants were than separated into roots, stems and leaves and dried at 600C in a convection oven for 48 hours.The metals from the plant were extracted using wet digestion process. Pearson’s coefficient correlation analysis was used to measure the relationship between Pb concentration in the soil and in plant tissues. The highest concentration was recorded in the roots of plants at 50 ppm concentration. A. Caudatus plants exposed to 25 ppm of Pb showed highest increase in root and stem growth. The lowest root growth was observed in plants exposed to 100 ppm of Pb. There is a negative relationship between the concentration of Pb in the soil and that in the above ground plant tissues. Key Words: Accumulation, Amaranthus, Lead, Phytoremediation

The Interplay Between Epigenetics, Vector Competence and Vaccine Immunodynamics as a Possible Explanation for Recent Yellow Fever Resurgence in Nigeria

Background: Yellow fever virus (YFV), a member of the genus Flaviviridae is the causative agent of YFD. The virus is classified as single-stranded RNA which is mostly transmitted by mosquitoes identified by Walter Reed in the year 1900 as Aedes aegypti [4]. In the past, Nigeria had been facing asporadic outbreaks of Yellow fever (YF), which began with the populous Northern region of the country. Aedes species of mosquitoes mainly transmit yellow fever virus (YFV) and vaccination is the only effective means of preventing it.Objectives: This article presents a critical review and literature updates on the vector biology, YF vaccine immunodynamics and epigenetics of YFV, with the aim to understand the interplay of these factors in the re-emergence of YF and risk assessment of living or traveling to YF endemic areas. (in the year 2016-2018)Methodology: The live, attenuated viral strain of the 17D vaccine was administered to tourists and inhabitants of endemic regions of Africa (Figure: 2) and South America. Those eligible for the vaccine were usually given through routes of administration either by single subcutaneous or intramuscular injection. The vaccine (17D-204 strain) could be given either to infants (pediatric dosage) above 9 months or adults (adult dosage) using one dose of subcutaneous injection (≥4.74 log10 plaque-forming units/0.5mL) not later than 10 days to regional migrationConclusion: Vectorial migration, jungle-to-urban spillover, immunization failure (especially in persons with chronic immune-mediated inflammatory diseases) and perhaps, genetic modification of YFV could be reasons for the resurgence of YF in the country. The single dose of the vaccine was usually sufficient to confer prolonged immunity against the infection but booster doses were often required based on endemic state of certain countries' Medical Laboratory Staff who frequently work on wild-type yellow fever virus. Based on regular exposure to this virus on routine basis, the neutralizing antibody titers against the virus are usually assessed every ten years to determine the necessity for booster doses of the 17D vaccine. Irrespective of the knowledge of neutralizing antibody titers for the virus, vaccination every 10 years is recommended especially for individuals frequently exposed to the virRecommendations: Increase vaccination coverage. Include YF vaccine in childhood vaccination programs. Make effort to maintain and control future outbreaks. Keywords: Vaccination, Genetics, Yellow Fever, Re-emergenc

Humoral immunological kinetics of severe acute respiratory syndrome coronavirus 2 infection and diagnostic performance of serological assays for coronavirus disease 2019: an analysis of global reports

As the coronavirus disease 2019 (COVID-19) pandemic continues to rise and second waves are reported in some countries, serological test kits and strips are being considered to scale up an adequate laboratory response. This study provides an update on the kinetics of humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and performance characteristics of serological protocols (lateral flow assay [LFA], chemiluminescence immunoassay [CLIA] and ELISA) used for evaluations of recent and past SARS-CoV-2 infection. A thorough and comprehensive review of suitable and eligible full-text articles was performed on PubMed, Scopus, Web of Science, Wordometer and medRxiv from 10 January to 16 July 2020. These articles were searched using the Medical Subject Headings terms 'COVID-19', 'Serological assay', 'Laboratory Diagnosis', 'Performance characteristics', 'POCT', 'LFA', 'CLIA', 'ELISA' and 'SARS-CoV-2'. Data from original research articles on SARS-CoV-2 antibody detection >= second day postinfection were included in this study. In total, there were 7938 published articles on humoral immune response and laboratory diagnosis of COVID-19. Of these, 74 were included in this study. The detection, peak and decline period of blood anti-SARS-CoV-2 IgM, IgG and total antibodies for point-of-care testing (POCT), ELISA and CLIA vary widely. The most promising of these assays for POCT detected anti-SARS-CoV-2 at day 3 postinfection and peaked on the 15th day; ELISA products detected anti-SARS-CoV-2 IgM and IgG at days 2 and 6 then peaked on the eighth day; and the most promising CLIA product detected anti-SARS-CoV-2 at day 1 and peaked on the 30th day. The most promising LFA, ELISA and CLIA that had the best performance characteristics were those targeting total SARS-CoV-2 antibodies followed by those targeting anti-SARS-CoV-2 IgG then IgM. Essentially, the CLIA-based SARS-CoV-2 tests had the best performance characteristics, followed by ELISA then POCT. Given the varied performance characteristics of all the serological assays, there is a need to continuously improve their detection thresholds, as well as to monitor and re-evaluate their performances to assure their significance and applicability for COVID-19 clinical and epidemiological purposes