Publications by authors named "Dorcas Owusu"

Tuberculosis (TB) is characterized by immunopathology in the blood and monocytes have been shown to be highly sensitive to plasma environment changes in TB patients. Here, we investigated TB plasma effects on 'reference monocytes' using RNA sequencing to characterize a potential immunomodulatory role of monocytes in TB. Candidate pathways induced by plasma samples from TB patients (n=99) compared to healthy controls (n=62) were analyzed for changes in signal transduction, phenotype and secreted cytokines by flow cytometry.

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Immunopathology of human tuberculosis (TB) in a subgroup of patients is characterized by aberrantly high concentrations of inflammatory cytokines, for example Interleukin (IL)-6. Concomitant (co-)infections by parasites can affect host immunity, but the impact on immunopathology in TB patients is poorly defined. Here we characterized a group of patients with TB ( n = 76) from Ghana with different protozoan and helminth co-infections.

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Article Synopsis
  • - The study focused on the impact of HIV and antiretroviral therapy (ART) on kidney health in West Africans, specifically looking at people receiving ART in central Ghana from 2003 to 2018, highlighting concerns over chronic kidney disease (CKD).
  • - Researchers examined data from 659 adults, finding that the use of tenofovir disoproxil fumarate (TDF) was linked to the highest decline in kidney function, while negative hepatitis B (HBsAg) status also correlated with increased eGFR decline.
  • - Overall, the findings suggest that specific ART drugs like TDF, nevirapine, and certain protease inhibitors contribute to faster declines in kidney function among people living with
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BCG vaccination affects other diseases beyond tuberculosis by unknown-potentially immunomodulatory-mechanisms. Recent studies have shown that BCG vaccination administered during overt type 1 diabetes (T1D) improved glycemic control and affected immune and metabolic parameters. Here, we comprehensively characterized Ghanaian T1D patients with or without routine neonatal BCG vaccination to identify vaccine-associated alterations.

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Xylene is the commonest clearing agent even though it is hazardous and costly. This study evaluated the clearing properties of coconut oil as an alternative cost-effective clearing agent for histological processes. Ten (10) prostate samples fixed in formalin were taken and each one was cut into 4 before randomly separating them into four groups (A, B, C and D).

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  • Culicoides, or biting midges, are known carriers of Mansonella perstans, a parasitic nematode causing disease, particularly prevalent in some Ghanaian communities.
  • The study sampled Culicoides species from various communities using different collection methods and identified six species, with C. imicola being the most common; C. grahamii was highlighted for its potential role in transmitting the parasite.
  • Findings showed a greater abundance of Culicoides during the wet season and employed LAMP assays to suggest that C. grahamii is a key vector for M. perstans transmission in the region.
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Host immune response is key for protection in tuberculosis, but the causative agent, Mycobacterium (M.) tuberculosis, manages to survive despite immune surveillance. Key mechanisms of immune protection have been identified, but the role of immunopathology in the peripheral blood of tuberculosis patients remains unclear.

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Article Synopsis
  • - Patients with tuberculosis (TB) exhibit impaired T-cell responses and high expression of T-cell activation markers, particularly among T-cells specific for Mycobacterium tuberculosis.
  • - A study involving 60 TB patients and 37 asymptomatic individuals found that TB patients had more CD38+ T-cells but similar overall proportions of PPD-specific T-cells compared to controls.
  • - Despite higher CD38 expression, TB patients' T-cells showed reduced responses to mitogens, which enhanced the effectiveness of the TAM-TB assay by using the PPD/PHA-induced T-cell ratio for classification.
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Immunopathology in human tuberculosis affects T-cell phenotype and functions. Previous studies identified impaired T-cell sensitivity to Interleukin (IL)-7 accompanied by lower IL-7 receptor α-chain (IL-7Rα) expression in patients with acute tuberculosis. In the present study, we characterized affected T-cell subsets and determined the influence of tuberculosis disease severity and treatment response.

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Background: Buruli ulcer disease (BUD) caused by Mycobacterium (M.) ulcerans is characterized by necrotic skin lesions. As for other mycobacterial infections, e.

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Monocyte-derived macrophages contribute centrally to immune protection in Mycobacterium tuberculosis infection and changes in monocyte phenotype characterize immunopathology in tuberculosis patients. Recent studies highlighted an important role of the plasma milieu in tuberculosis immunopathology. Here, we investigated monocyte pathology in patients with acute tuberculosis and determined tuberculosis plasma milieu effects on phenotype as well as cytokine signalling of reference monocytes.

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BCG vaccination is recommended for healthy babies after birth in several countries with a high prevalence of tuberculosis, including Ghana. Previous studies showed that BCG vaccination prevents individuals from developing severe clinical manifestations of tuberculosis, but BCG vaccination effects on the induction of IFN-γ after infection have hardly been investigated. Here, we performed IFN-γ-based T-cell assays (i.

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Background: Every minute, six indigenous Africans develop new strokes. Patient-level and system-level contributors to early stroke fatality in this region are yet to be delineated. We aimed to identify and quantify the contributions of patient-level and system-level determinants of inpatient stroke fatality across 16 hospitals in Ghana and Nigeria.

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Purpose: Human tuberculosis is characterized by immunopathology that affects T-cell phenotype and functions. Previous studies found impaired T-cell response to phytohemagglutinin (PHA) in patients with acute tuberculosis. However, the influence of disease severity, affected T-cell subsets, and underlying mechanisms remain elusive.

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Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies.

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There is a heavy burden of liver disease in West Africa. While the role of hepatitis B virus (HBV) infection is well recognized, less is known about the contributing role of liver steatosis and how the two interact in the context of human immunodeficiency virus (HIV) infection. Adults with HIV in Ghana underwent FibroScan measurements to determine prevalence of liver steatosis (expressed as controlled attenuation parameter [CAP]) and fibrosis (expressed as liver stiffness [LS]).

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Immune-based diagnosis of Buruli ulcer disease (BUD) in children is difficult due to cross-reactivity between mycobacteria. We found that T-cell IFNγ/TNFα responses against Mycobacterium (M.) ulcerans and M.

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Background: Mycobacterium (M.) tuberculosis-caused immunopathology is characterized by aberrant expression of plasma cytokines in human tuberculosis. Disease severity and long-term anti-mycobacterial treatment are potentially influenced by immunopathology and normalization of plasma cytokine levels during therapy may indicate treatment efficacy and recovery.

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Article Synopsis
  • Doxycycline is effective in treating Mansonella perstans infections, but its long-term effects on the host's immune system, particularly T-cell responses, were not well understood prior to this study.
  • The study involved analyzing immune parameters from M. perstans-infected individuals before, 6 months, and 18-24 months after doxycycline treatment, revealing significant changes in T-cell activation and polarization.
  • Results indicated that doxycycline treatment led to decreased T-cell activation and altered responses, particularly reducing effectiveness against co-infections like Mycobacterium tuberculosis, contributing to a complex immune modulation over time.
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We investigated the contributions of thymidine analogue and tenofovir disoproxil fumarate (TDF) antiretroviral therapy on renal mitochondrial toxicity in Ghanaian people with HIV (PWH). Similar levels of renal biochemical and mitochondrial dysfunction were seen, and there was no increased risk in PWH who had sequenced from thymidine analogue to TDF. However, mild renal impairment was associated with mitochondrial DNA damage in TDF but not thymidine analogue-treated PWH.

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Bacterial components and cytokines induce IL-7 receptor (IL-7Rα) expression in monocytes. Aberrant low IL-7Rα expression of monocytes has been identified as a feature of tuberculosis immunopathology. Here, we investigated the mechanisms underlying IL-7Rα regulation of monocytes and tuberculosis serum effects on IL-7Rα expression.

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Background And Purpose: To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans.

Methods: The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection.

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Introduction: lower respiratory tract infections (LRTIs) are infections involving the trachea, primary bronchi and lungs. People with LRTIs typically experience coughs as the primary symptoms; however, shortness of breath, weakness, fever and fatigue may be coupled with the cough. It is common among the aged, children under five and the immune-suppressed.

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Altered monocyte differentiation and effector functions characterize immune pathogenesis of tuberculosis. IL-7 is an important factor for proliferation of T cells and impaired IL-7 sensitivity due to decreased IL-7 receptor α-chain (IL-7Rα) expression was found in patients with acute tuberculosis. Peripheral blood monocytes have moderate IL-7Rα expression and increased IL-7Rα levels were described for inflammatory diseases.

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Introduction: active or chronic exacerbated forms of hepatitis C virus (HCV) infection subsequently progress to liver disease and human defensins has been determined to have some level of anti-viral properties invitro whilst the expression of T helper-1 cytokines is known to promote complete recovery from acute HCV infection. The study sought to determine relationship between these immune responses.

Methods: a cross sectional descriptive study design was employed.

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