Browsing by Author "Kwarteng, Alexander"
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- ItemBlood collection tubes impact expression of activated CD4+ and CD8+ T cells in human whole blood assay(Scientific African, 2023) Kwarteng, Alexander; Osei-Poku, Priscilla; Antwi-Berko, Daniel; Sylverken, Augustina Angelina; Larbi, Amma; Nsiah, Kwabena; 0000-0002-0893-2908; 0000-0002-9187-2503; 0000-0001-8994-1349; 0000-0002-7691-914X; 0000-0002-3814-6924; 0000-0001-8500-0963Background T-lymphocyte subsets CD4 and CD8 play important role in host immune responses. However, little attention has been given to the impact of time lapse and the various anticoagulant blood collection tubes on the expression frequency and activation status of CD4+ and CD8+ T cells. To this end, we explore the impact of time (t<1 h and t=4 h) and collection tubes (EDTA and heparin) on the expression frequency and activation status of CD4+ and CD8+ T cells among healthy Ghanaian individuals. Methods A cohort of healthy individuals (n=9) is recruited, and blood samples obtained in Ghana for the frequency of CD4+and CD8+ T cells at various time points (<1 h and 4 h). The proportions of activation of these immune markers were profiled using immunophenotyping. Results Significant statistical differences in the activation frequency of CD69 expressing CD4+T cells (t < 1 h and t=4 h; p=0.02) and CD69 expressing CD8+ T cells from EDTA tubes at times (t < 1 h and t=4 h; p=0.05) was observed. No significant difference were observed with CD69 expressing cells in Heparin tubes. Notably, CD8+ T cell activation frequency was observed to be consistently higher than that of CD4+ T cell at the various study time points and in the collection tubes used. No marked alterations were observed witth the proportion of CD4+ and CD8+ T cells in the samples collected at the time points; <1 h and at 4 h. Conclusion The study shows that activation of CD4+ and CD8+ T cells in EDTA tubes differed significantly between both time points (t <1 h and t=4 h) but not in the heparin collection tubes. Therefore, it is important to take into account the elapsed time and the type of blood collection tubes when performing phenotypic characterization of activated immune markers.
- ItemBurden of respiratory viral infections among inmates of a Ghanaian prison(Research Gate Publication, 2019-09-08) Sylverken, Augustina Angelina; El-Duah, Philip; Owusu, Michael; Yeboah, Richmond; Kwarteng, Alexander; Ofori, Linda; Gorman, Richmond; Obiri-Danso, Kwasi; Owusu-Dabo, Ellis; 0000-0002-7691-914X; 0000-0003-1671-0755; 0000-0003-1671-0755; 0000-0002-2765-6179; 0000-0002-0893-2908; 0000-0002-6831-3375; 0000-0002-5497-1684; 0000-0003-4232-4292Respiratory viral infections are important causes of morbidity and mortality worldwide. Information on circulating respiratory viruses among prisoners is lacking, although this is of public health importance and knowledge would assist in putting in place preventive measures to forestall disease outbreaks. The aim of this study therefore was to get the footprint of such diseases that have epidemic potential to be described and quantified for control. Prisoners on remand numbering 203 in a prison in Kumasi, the Ashanti Regional capital, were interviewed using prevalidated questionnaire, nasopharyngeal samples taken and screened by real-time PCR for common respiratory viruses in February, 2018. Of the total number of 203 participants enrolled, majority were males (n = 198, 97.54%). The modal age unsurprisingly was in the active working class of 18 to 35 years (n = 155, 76.36%) with 48 (23.65%) of participants older than 35 years. Inmates reported nasal congestion (n = 83, 40.89%), cough with or without pharyngitis (n =108, 53.20%) and fever (n = 74, 39.48%). Viruses detected in throat samples were Infl uenza A (n = 1, 0.49%) and Rhinovirus (n = 8, 3.94%). There was no statistically significant association between respiratory virus positivity and age (p = 0.118), gender (p > 0.900), duration of incarceration (p = 0.239) and reported symptoms (p = 0.724). The prison population may have a lower prevalence of respiratory viruses circulating in them. This may be dominated by those with high antigenic diversity.
- ItemMolecular characterization of interactions between the D614G variant of SARS-CoV-2 S-protein and neutralizing antibodies: A computational approach(Infection, Genetics and Evolution, 2021) Kwarteng, Alexander; Asiedu, Ebenezer; Sylverken, Augustina Angelina; Larbi, Amma; Sakyi, Samuel Asamoah; Asiedu, Samuel Opoku; 0000-0002-0893-2908; 0000-0003-2867-1984; 0000-0002-7691-914X; 0000-0002-3814-6924; 0000-0001-5168-4762; 0000-0002-0352-3195The D614G variant of SARS-CoV-2 S-protein emerged in early 2020 and quickly became the dominant circulating strain in Europe and its environs. The variant was characterized by the higher viral load, which is not associated with disease severity, higher incorporation into the virion, and high cell entry via ACE-2 and TMPRSS2. Previous strains of the coronavirus and the current SARS-CoV-2 have demonstrated the selection of mutations as a mechanism of escaping immune responses. In this study, we used molecular dynamics simulation and MM-PBSA binding energy analysis to provide insights into the behaviour of the D614G S-protein at the molecular level and describe the neutralization mechanism of this variant. Our results show that the D614G S-protein adopts distinct conformational dynamics which is skewed towards the open-state conformation more than the closed-state conformation of the wild-type S-protein. Residue-specific variation of amino acid flexibility and domain specific RMSD suggest that the mutation causes an allosteric conformational change in the RBD. Evaluation of the interaction energies between the S-protein and neutralizing antibodies show that the mutation may enhance, reduce or not affect the neutralizing interactions depending on the neutralizing antibody, especially if it targets the RBD. The results of this study have shed insights into the behaviour of the D614G S-protein at the molecular level and provided a glimpse of the neutralization mechanism of this variant.
- ItemUse of social media in a national Tuberculosis Drug Resistance Survey: lessons from the first anti-tuberculosis drug resistance survey in Ghana(AAS Open Research, 2019) Sylverken, Augustina Angelina; Owusu-Dabo, Ellis; Kwarteng, Alexander; Twumasi-Ankrah, Sampson; Owusu, Michael; Adu-Amoah, Louis; Dumevi, Rexford Mawunyo; Arthur, Rejoice Agyeiwaa; Addofoh, Nicholas; Dzata, Francisca; Bonsu, Frank; 0000-0002-7691-914X; 0000-0003-4232-4292; 0000-0002-0893-2908; 0000-0002-9183-1883; 0000-0001-5066-150X; 0000-0001-6755-2545; 0000-0002-7135-2754Background: The widespread use of social media applications on mobile phones indicate that smart phones have become more than just a simple medium for voice calling. Several studies have shown the potential benefit of these social media applications in discussing many health conditions. We report on tracking sample transport by public and private transport providers using WhatsApp during the first nationwide drug resistance tuberculosis (TB) survey in Ghana. Methods: The survey was conducted between February 2016 and June 2017, and involved 33 TB diagnostic sites selected on the basis of a two-stage cluster randomized sampling design on both anticipated yield and probability proportional to size method. We engaged the services of privately and publicly owned vehicles’ union to transport samples to the central laboratories in Kumasi for further laboratory processing.We created a mobile social group platform (‘National TBDRS’) on WhatsApp consisting of two representatives from each site as well as other stakeholders. The purpose was to notify a laboratory team in Kumasi, on the following details of the sample: date and time of dispatch, driver’s name, car number, estimated time of arrival, and bus terminal name. Results: A total 3077 WhatsApp messages were received during the survey period. Of these, 2879 (93.57%) messages were related to the survey. We observed a positive correlation between the total number of messages received and the total number of well-packaged sputum samples sent (r=0.89, p=0.02). There were no major transport delays (11:44±03:50) and all samples arrived within a 3-day window from the survey sites. Conclusions: Using WhatsApp as a platform of communication can significantly aid in improving tracking of samples, enhance accountability of for example drivers handling the samples over at a road crossing and communication across health facilities.