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INTRODUCTION : the diagnosis of Lassa fever is crucial to confirm cases, as well as to control/prevent nosocomial and community-based transmission and initiation of treatment, which is still limited in the country. Thus, we aimed at providing some information on the laboratory detection of Lassa from suspected cases in Nigeria.Methods: this was a retrospective study of seasonal Lassa fever outbreaks data from 1,263 samples analyzed using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) at the Virology Research Laboratory, College of Medicine, University of Lagos/Lagos University Teaching Hospital between year 2011 and 2017. Data were analyzed using the 21st edition of SPSS statistical software (2015).Results: the RT-PCR test confirmed the presence of Lassa in 112 (8.9%) comprising 61 (54.4%) males, 48 (42.9%) females and 3 (2.7%) individuals without gender information. Those aged between 18 and 49 years were mostly affected. There was a decline in the detection of Lassa from 4.7% in 2011/2012 to less than 1% by the 2014/2015. However, during the 2015/2016 and 2016/2017 seasons the detection rates increased to 10.4% and 15.1% respectively. The Northern region of Nigeria reported high confirmed cases of Lassa. The South Western region also witnessed an increased Lassa fever positivity rate of 13.4% of which Lagos and Ogun states being the focal state of Lassa activity in the region.Conclusion: these established the need for heightening the continued surveillance for lassa as well as the establishment of other testing facilities within these endemic regions for prompt diagnosis of lassa fever.

The aim of this study was to evaluate the aging effect of thermomechanical cyclic load on fracture resistance of lower premolars obturated with AH Plus and BioRoot RCS root canal sealers. Forty-eight single-rooted premolars teeth were instrumented with REVO-S files up to SU/0.06 taper. The teeth were randomly assigned into 2 main groups (n = 24) according to the selected two root canal sealers (AH Plus or BioRoot RCS). All teeth were obturated using matching gutta-percha. Each main group were further divided into 3 subgroups (A, B and C) (n = 8). Group A acted as the negative control group (non-Thermomechanical aging). Whereas Group B and C were subjected first to thermal variations in a thermal cycling machine (7500 and 15,000 thermal cycles), then two different dynamic loading periods namely 3 × 105 and 6 × 105 in a masticatory simulator with a nominal load of 5 kg at 1.2 Hz which simulate approximately 1 ½ and 3 years of clinical function respectively. The roots were decoronated and fracture resistance were measured using a universal testing machine. After thermal-mechanical aging, BioRoot RCS showed significantly higher fracture resistance (p < 0.05) than AH Plus. As the thermal-mechanical cycles increased both AH Plus and BioRoot RCS exhibited a significant decrease in fracture resistance (p < 0.05). It could be concluded that thermomechanical aging had a significant impact on the outcome of the fracture resistance of AH Plus and BioRoot RCS. [ABSTRACT FROM AUTHOR]

Introduction: heightened surveillance of the severe acute respiratory syndrome coronavirus-2 (SARSCoV-2) 2019 outbreak in Wuhan, China activated several collaborative laboratory drills on its detection by health institutions in Nigeria. We hereby detail the laboratory detection and confirmation of the novel SARS-CoV-2 virus of the index case imported into Nigeria. Methods: viral RNA from sputum sample of the index case was tested for SARS-CoV-2 envelope (E) and RNA dependent RNA polymerase (RdRp) genes using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Genetic analysis using a partial sequence of RdRp gene was used for laboratory confirmation, evolutionary inferences, and relatedness to previous strains of betacorona viruses in Nigeria. Results: both qRT-PCR for the E and RdRp genes indicated the presence of the SARSCoV-2 RNA by showing cycle threshold (ct) values of 20.27 and 25.26 respectively. On successful completion of the sequencing run, data aligned with >98% similarity of the 2019 circulating strain of Coronavirus SARS-CoV-2. Evolutionary algorithms revealed that the sequence (RdRp gene) of the outbreak circulating strains were more conserved unlike previous coronavirus outbreaks. Data showed that some coronaviruses belonging to the BetaCoV genus had earlier been reported in bats and camels in Nigeria indicating the possibility of sero-protection in exposed populations. Conclusion: pre-laboratory drills prompted early diagnosis and confirmation of SARS-CoV-2 index case in Nigeria initiating rapid case-definition, contact tracing, and successful epidemiological management of the outbreak. Rapid sequencing of the viral genome during strategic points of the outbreak curve and making libraries of new variants for improved vaccine development are recommended. [ABSTRACT FROM AUTHOR]

Lead (Pb(2+)) exposure continues to be a significant public health problem. Therefore, it is vital to have a continuous epidemiological dataset for a better understanding of Pb(2+) toxicity. In the present study, we have exposed stem cells isolated from deciduous and permanent teeth, periodontal ligament, and bone marrow to five different types of Pb(2+) concentrations (160, 80, 40, 20, and 10 µM) for 24 hours to identify the adverse effects of Pb(2+) on the proliferation, differentiation, and gene expression on these cell lines. We found that Pb(2+) treatment altered the morphology and adhesion of the cells in a dose-dependent manner. There were no significant changes in terms of cell surface phenotypes. Cells exposed to Pb(2+) continued to differentiate into chondrogenesis and adipogenesis, and a severe downregulation was observed in osteogenesis. Gene expression studies revealed a constant expression of key markers associated with stemness (Oct 4, Rex 1) and DNA repair enzyme markers, but downregulation occurred with some ectoderm and endoderm markers, demonstrating an irregular and untimely differentiation trail. Our study revealed for the first time that Pb(2+) exposure not only affects the phenotypic characteristics but also induces significant alteration in the differentiation and gene expression in the cells.