Papers by DAVID BAIDOE-ANSAH
Cells, Jun 27, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Cells, 2021
The extracellular matrix (ECM) plays a key role in synaptogenesis and the regulation of synaptic ... more The extracellular matrix (ECM) plays a key role in synaptogenesis and the regulation of synaptic functions in the central nervous system. Recent studies revealed that in addition to dopaminergic and serotoninergic neuromodulatory systems, microglia also contribute to the regulation of ECM remodeling. In the present work, we investigated the physiological role of microglia in the remodeling of perineuronal nets (PNNs), predominantly associated with parvalbumin-immunopositive (PV+) interneurons, and the perisynaptic ECM around pyramidal neurons in the hippocampus. Adult mice were treated with PLX3397 (pexidartinib), as the inhibitor of colony-stimulating factor 1 receptor (CSF1-R), to deplete microglia. Then, confocal analysis of the ECM and synapses was performed. Although the elimination of microglia did not alter the overall number or intensity of PNNs in the CA1 region of the hippocampus, it decreased the size of PNN holes and elevated the expression of the surrounding ECM. In the...
Annals of Medical and Health Sciences Research, 2017
Background: It is essential that methods for genomic DNA extraction techniques produce high yield... more Background: It is essential that methods for genomic DNA extraction techniques produce high yield and purified DNA. Commercially available DNA extraction kits have taken over the traditional DNA extraction techniques. However, to meet the demands of cost-effectiveness, ready availability, safety, reliability and purity in resource-limited settings, an improved traditional DNA extraction method which meet the above criteria is required. Aim: We therefore evaluated the modified salting out and double salt precipitation method, against QIAamp Blood Mini Kit. Materials and Methods: In a cross-sectional study, DNA was extracted from venous blood of 60 suspected typhoid fever patients who visited the Komfo Anokye Teaching Hospital diagnostics department to do laboratory investigations that required blood collection. Their DNA was extracted using the three different methods. Spectrophotometric measurement of the yields (ng/μl) and purities (260/280 nm) of the extracted DNA was done. PCR an...
Glia, 2020
In the advanced stages of Alzheimer's disease (AD), microglia are transformed to an activated phe... more In the advanced stages of Alzheimer's disease (AD), microglia are transformed to an activated phenotype with thickened and retracted processes, migrate to the site of amyloid-beta (Aβ) plaques, and proliferate. In the early stages of AD, it is still poorly understood whether the microglial function is altered and which factors may regulate these changes. Here, we focused on studying microglia in the retrosplenial cortex (RSC) in 3-to 4-month-old 5xFAD mice as a transgenic mouse model of AD. At this age, there are neither Aβ plaques, nor activation of microglia, nor dysregulation in the expression of genes encoding major extracellular matrix (ECM) molecules or extracellular proteases in the RSC. Still, histochemical evaluation of the fine structure of neural ECM revealed increased levels of Wisteria floribunda agglutinin labeling in holes of perineuronal nets and changes in the perimeter of ECM barriers around the holes in 5xFAD mice. Two-photon vital microscopy demonstrated normal morphology and resting motility of microglia but strongly diminished number of microglial cells that migrated to the photolesion site in 5xFAD mice. Enzymatic digestion of ECM by chondroitinase ABC (ChABC) ameliorated this defect. Accordingly, the characterization of cell surface markers by flow cytometry demonstrated altered expression of microglial CD45. Moreover, ChABC treatment reduced the invasion of myeloidderived mononuclear cells into the RSC of 5xFAD mice. Hence, the migration of both microglia and myeloid cells is altered during the early stages of amyloidosis and can be restored at least partially by the attenuation of the ECM.
Heliyon, 2020
Background: Paediatric sepsis remains a major public health problem with significant morbidity an... more Background: Paediatric sepsis remains a major public health problem with significant morbidity and mortality especially in developing countries. Clinical symptoms associated with sepsis are unreliable and laboratory parameters unspecific, making an early diagnosis of paediatric sepsis difficult. The lack of definitive biomarker(s) for early diagnosis of sepsis further leads to the misuse of antibiotics. Diagnosis based on a single biomarker does not provide adequate accuracy. Subsequently, combining multiple biomarkers into a single score will help clinicians make a better diagnostic judgment. Aims: This study for the first time evaluated the individual and combined diagnostic accuracy of procalcitonin (PCT), presepsin (sCD14-ST) and high sensitive C-reactive protein (hs-CRP) using a Bioscore model. Materials and methods: In a case control study conducted at the Paediatric Emergency Unit (PEU) and the Mother and Baby Unit (MBU) of Komfo Anokye Teaching Hospital (KATH), sixty (60) paediatric subjects aged zero to six (0-6) years, were diagnosed with sepsis using case-definition by the national neonatal bloodstream infection surveillance and Pediatric Sepsis Consensus Congress. Thirty (30) other paediatric subjects, aged and sex matched without sepsis or inflammatory conditions were used as controls. One-time blood sample was taken at the time of admission for blood culture and measurement of PCT, hs-CRP, and presepsin by ELISA. The Statistical Package for Social Sciences (SPSS release 20.0, Copyright ©SPSS Inc.) was used for analysis. Results: Out of the sixty septic paediatric subjects, 14 patients (23.3%) had positive blood cultures (LCS) and 46 (76%) had negative for blood cultures (CS). Klebsiella spp. recorded the highest median levels of PCT, and hs-CRP while Pseudo. Aeruginasa recorded the highest of sCD14-ST levels. Significant elevations in PCT, sCD14-ST and hs-CRP levels were observed among septic cases in comparison to controls (p < 0.0001). Individually, PCT showed better accuracy (AUC ¼ 78.7%) followed by hs-CRP (AUC ¼ 78.4%) and sCD14-ST (AUC ¼ 74.8%). Combination of PCT þ hs-CRP had the highest accuracy (AUC ¼ 80.1%) followed by hs-CRP þ sCD14-ST (AUC ¼ 77.2%), PCT þ sCD14-ST þ hs-CRP (AUC ¼ 77.0%) and PCT þ sCD14-ST (AUC ¼ 75.9%). Conclusion: hs-CRP, PCT, and sCD14-ST are independent predictors of paediatric sepsis due to their high prognostic values. Moreover, Bioscore combination of these biomarkers was significantly associated with increased odds for sepsis. The incorporation of these biomarkers into routine diagnostic tests will aid in prompt diagnosis of paediatric sepsis.
Neural extracellular matrix (ECM) is a complex molecular meshwork surrounding neurons and glial c... more Neural extracellular matrix (ECM) is a complex molecular meshwork surrounding neurons and glial cells in the extracellular space. Structural and functional state of ECM in the brain is tightly regulated by various components of neural ECM such as hyaluronic acid, chondroitin sulfate proteoglycans, link proteins, tenascins, various matrix-modifying enzymes such as chondroitin sulfate synthases and carbohydrate sulfotransferase together with matrix-degrading enzymes. Age-dependent accumulation of ECM molecules is implicated in the age-associated decline in synaptic and cognitive functions. Understanding age-associated changes in the expression of genes involved in regulating various components of ECM can provide an insight into the role of ECM in the aging brain. Hence, in this study, we compared the expression levels of ECM regulating genes in three groups of mice: 2-3 months old mice (2-3M), 22- to 26-month-old mice (22-26M) and more than 30-month-old mice (>30M). Using qPCR, we ...
Our previous studies demonstrated that enzymatic removal of highly sulfated heparan sulfates with... more Our previous studies demonstrated that enzymatic removal of highly sulfated heparan sulfates with heparinase 1 impaired axonal excitability and reduced expression of ankyrin G at the axon initial segments in the CA1 region of the hippocampus ex vivo, impaired context discrimination in vivo, and elevated Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity in vitro. Here, we show that in vivo delivery of heparinase 1 in the CA1 region of the hippocampus elevated autophosphorylation of CaMKII 24 hours after injection in mice. Patch-clamp recording in CA1 neurons revealed no significant heparinase effects on the amplitude or frequency of miniature excitatory and inhibitory postsynaptic currents, while the threshold for action potential generation was increased and fewer spikes were generated in response to current injection. Delivery of heparinase on the next day after contextual fear conditioning induced context overgeneralization 24 hours after injection. Co-administration o...
This thesis is presented to the Department of Biochemistry & Biotechnology in partial fulfillment... more This thesis is presented to the Department of Biochemistry & Biotechnology in partial fulfillment for the requirement for the Award of Master of Science in Biotechnology. 2015
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Papers by DAVID BAIDOE-ANSAH