ORCID Profile
0000-0001-5207-5942
Current Organisations
University of Cape Coast
,
Edith Cowan University
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Publisher: Science Alert
Date: 07-2015
Publisher: Hindawi Limited
Date: 2016
DOI: 10.1155/2016/8252741
Abstract: The young leaves of Vernonia amygdalina are often utilized as vegetable and for medicinal purpose compared to the old leaves. This study was designed to evaluate and compare the antidiabetic effects between ethanolic leaf extracts of old and young V. amygdalina on streptozotocin (STZ) induced diabetic rat for four weeks. Preliminary screening of both young and old ethanolic extracts revealed the presence of the same phytochemicals except flavonoids which was only present in the old V. amygdalina . Difference in antioxidant power between the young and old leaf extracts was statistically significant ( p 0.05 ). Both leaf extracts produced a significant ( p 0.05 ) antihyperglycaemic effect. Also results from treated rats revealed increasing effect in some haematological parameters. Similarly, the higher dose (300 mg/kg) of both extracts significantly ( p 0.05 ) reduced serum ALT, AST, and ALP levels as compared to the diabetic control rats. Results also showed significant ( p 0.05 ) decrease in LDL-C and VLDL-C in the extract-treated rats with a corresponding increase in HDL-C, as compared to the diabetic control rats. Moreover histopathological analysis revealed ameliorative effect of pathological insults induced by the STZ in the pancreas, liver, and spleen, most significantly the regeneration of the beta cells of the islets of Langerhans in treated rats.
Publisher: Hindawi Limited
Date: 2017
DOI: 10.1155/2017/5618548
Publisher: Springer Science and Business Media LLC
Date: 13-02-2023
DOI: 10.1038/S41598-023-29416-Z
Abstract: Circulating tumour cells (CTCs) are heterogenous and contain genetic information from the tumour of origin. They bear specific intra- and extra-cellular protein markers aiding in their detection. However, since these markers may be shared with other rare cells in the blood, only genetic testing can confirm their malignancy. Herein, we analyse different CTC subsets using single cell whole genome DNA sequencing to validate their malignant origin. We randomly selected putative CTCs identified by immunostaining that were isolated from 4 patients with high grade serous ovarian cancer (HGSOC) and one with benign cystadenoma. We specifically targeted CTCs positive for epithelial (CK/EpCAM pos ), mesenchymal (vimentin pos ), and pseudoendothelial (CK/EpCAM pos plus CD31 pos ) markers. We isolated these cells and performed whole genome lification (WGA) and low-pass whole-genome sequencing (LP-WGS) for analysis of copy number alterations (CNA). Of the CK/EpCAM pos cells analysed from the HGSOC patients, 2 of 3 cells showed erse chromosomal CNAs. However, the 4 pseudoendothelial cells (CK/EpCAM pos plus CD31 pos ) observed in the HGSOC cases did not carry any CNA. Lastly, two of the clusters of vimentin positive cells sequenced from those found in the benign cystadenoma case had CNA. Despite the low number of cells analysed, our results underscore the importance of genetic analysis of putative CTCs to confirm their neoplastic origin. In particular, it highlights the presence of a population of CK/EpCAM pos cells that are not tumour cells in patients with HGSOC, which otherwise would be counted as CTCs.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.BIOPHA.2018.12.147
Abstract: Both young and old leaves of Vernonia amygdalina (VA) are traditionally used to treat inflammation, pain and fever. However, the efficacy of young and old leaves for treating these ailments have not been compared till date. To ascertain the effect of young and old leaves of VA in managing inflammation, pain and fever. Both quantitative and qualitative phytochemical screening of ethanol extracts of young (EthYL) and old (EthOL) leaves of VA were performed. The anti-inflammatory activity of orally administered EthYL and EthOL (50-200 mg/kg) and Diclofenac (10 mg/kg) were evaluated in carrageenan-induced inflammation model in rats. Antipyretic activity of EthYL, EthOL and Aspirin (25 mg/kg) were assessed in the Baker's yeast-induced pyrexia model. Anti-allodynic effect of both extracts were evaluated by inserting inflamed paws of rats in cold water. Antinociceptive property of the extracts were assessed using tail withdrawal and formalin-induced nociception test. Histopathological examination of the paws was performed, in addition to formalin test to understand the possible mechanism of action of the extracts. Negative control rats received 2 ml/kg normal saline in all tests. The amount of flavonoids, alkaloids, tannins, and phenolics were significantly (p < 0.05) higher in EthOL than EthYL, while saponins were significantly higher (p < 0.05) in EthYL than EthOL. The antioxidant ability and total antioxidant capacity were significantly (p < 0.05) higher in EthYL than EthOL. However, this was significantly (p < 0.05) lower than the anti-oxidant activity of Ascorbic acid. A dose-dependent increase in anti-inflammatory, antipyretic and antinociceptive properties were observed in both EthYL and EthOL, similar to the standard drugs. Mast cell degranulation accompanied by vasodilatation and high leukocytosis were observed in the negative control, but were markedly low in extract treated groups. Both extracts mediated their analgesic effect through opioidergic and nitric oxide pathways with EthYL additionally implicating the muscarinic cholinergic system. Although both EthYL and EthOL alleviate inflammation, pyrexia and nociception, EthYL of VA was found to be more potent than EthOL.
Publisher: AME Publishing Company
Date: 03-2022
DOI: 10.21037/TLCR-21-819
Publisher: Hindawi Limited
Date: 2017
DOI: 10.1155/2017/2721367
Abstract: Nasopharyngeal carcinomas (NPC) are endemic in Far East Asia and commonly harbour Epstein-Barr virus (EBV) which is known to serve as a key oncogenic promoter. Human papillomavirus (HPV) is known to contribute to the pathogenesis of NPC. However, in Ghana these two viruses have not been linked to NPC prevalence. This study was designed to determine the HPV genotypes and EBV involved in NPC tissue biopsies. A retrospective study design involving 72 formalin-fixed paraffin-embedded tissue (FFPET) s les of NPC from 2006 to 2012 were retrieved from the Department of Pathology, University of Ghana School of Biomedical and Allied Health Sciences. Sections were taken for histological analysis and for DNA lysate preparation. The DNA lysates were subjected to polymerase chain reaction (PCR) analysis to determine the presence of HPV genotypes and EBV. HPV specific primers were used to type for fourteen HPV genotypes (HPV-16, 18, 6/11, 31, 33, 35, 44, 42, 43, 45, 56, 52, 58, and 59). Out of the 72 NPC biopsies analyzed by PCR, EBV DNA was present in 18 (25%) cases and HPV DNA in 14 (19.23%). High risk HPV (HR-HPV) genotypes 18 and 31 were associated with the NPC. There were 3 (4.2%) cases of coinfection by both viruses. The EBV DNA present in the undifferentiated variant of the NPC and the histopathology of the NPC in Ghana is similar to the type described in endemic areas.
Publisher: PAGEPress Publications
Date: 12-01-2023
Abstract: Background. Dermatosis papulosa nigra (DPN) affects sun-exposed areas such as the face, neck, and trunk. The prevalence of pterygium and myopia in DPN patients in Ghana has not been studied. In this study, we examined the risk and protective factors for pterygium and myopia in DPN patients. Materials and Methods. The study involved 100 participants with facial DPN. A standard ophthalmic exam was performed using a portable slit l and a 3.5X magnified loop. Participants completed a closed- ended questionnaire. Logistic regression was used to summarize the level of association between DPN, myopia, and pterygium, as well as demographic factors (gender, age, occupation, family history of lesion and skin complexion). Results. 70% and 84% of participants had pterygium and myopia. Age, gender, complexion, and sun exposure were associated with pterygium and myopia (p 0.05). Higher grade of pterygium and myopia were prevalent in the aged population. Both univariate and multivariable models highlighted that increasing age and sun exposure (outdoor) were risk factors for developing higher grade of pterygium and myopia in the DPN participants, while light skin color and male gender were respectively identified as protective factors. Conclusions. Our study is the first to examine pterygium and myopia in facial DPN patients. Most Ghanaians with facial DPN are at risk for developing pterygium and myopia.
Publisher: Elsevier BV
Date: 2018
DOI: 10.1016/J.BIOPHA.2017.10.100
Abstract: The standard therapy of AML for many years has been chemotherapy with or without stem transplantation. However, there has not been any tangible improvement in this treatment beyond induction through chemotherapy and consolidation with allogeneic stem cell transplantation or chemotherapy. Residual AML cells which later cause relapse mostly persist even after rigorous standard therapy. It is imperative therefore to find an alternative therapy that can take care of the residual AML cells. With a better understanding of how the immune system works to destroy tumor cells and inhibit their growth, another therapeutic option immunotherapy has emerged to address the difficulties associated with the standard therapy. Identification of leukemia-associated antigens (LAA) and the fact that T and NK cells can be activated to exert cytotoxicity on AML cells have further introduced erse immunotherapeutic development strategies. This review discusses the merits of current immunotherapeutic strategies such as the use of antibodies, adoptive T cells and alloreactive NK cell, and vaccination as against the standard therapy of AML.
Publisher: Elsevier BV
Date: 2019
Publisher: Medknow
Date: 06-2015
Publisher: MDPI AG
Date: 10-12-2021
Abstract: Detection of ovarian cancer (OC) circulating tumour cells (CTCs) is primarily based on targeting epithelial markers, thus failing to detect mesenchymal tumour cells. More importantly, the immune checkpoint inhibitor marker PD-L1 has not been demonstrated on CTCs from OC patients. An antibody staining protocol was developed and tested using SKOV-3 and OVCA432 OC cell lines. We targeted epithelial (cytokeratin (CK) and EpCAM), mesenchymal (vimentin), and OC-specific (PAX8) markers for detection of CTCs, and CD45/16 and CD31 were used for the exclusion of white blood and vascular endothelial cells, respectively. PD-L1 was used for CTC characterisation. CTCs were enriched using the Parsortix™ system from 16 OC patients. Results revealed the presence of CTCs in 10 (63%) cases. CTCs were heterogeneous, with 113/157 (72%) cells positive for CK/EpCAM (epithelial marker), 58/157 (37%) positive for vimentin (mesenchymal marker), and 17/157 (11%) for both (hybrid). PAX8 was only found in 11/157 (7%) CTCs. In addition, 62/157 (39%) CTCs were positive for PD-L1. Positivity for PD-L1 was significantly associated with the hybrid phenotype when compared with the epithelial (p = 0.007) and mesenchymal (p = 0.0009) expressing CTCs. Characterisation of CTC phenotypes in relation to clinical outcomes is needed to provide insight into the role that epithelial to mesenchymal plasticity plays in OC and its relationship with PD-L1.
Publisher: Medknow
Date: 07-2016
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.CANLET.2019.10.014
Abstract: Liquid biopsies hold the potential to inform cancer patient prognosis and to guide treatment decisions at the time when direct tumor biopsy may be impractical due to its invasive nature, inaccessibility and associated complications. Specifically, circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) have shown promising results as companion diagnostic biomarkers for screening, prognostication and/or patient surveillance in many cancer types. In ovarian cancer (OC), CTC and ctDNA analysis allow comprehensive molecular profiling of the primary, metastatic and recurrent tumors. These biomarkers also correlate with overall tumor burden and thus, they provide minimally-invasive means for patient monitoring during clinical course to ascertain therapy response and timely treatment modification in the context of disease relapse. Here, we review recent reports of the potential clinical value of CTC and ctDNA in OC, expatiating on their use in diagnosis and prognosis. We critically appraise the current evidence, and discuss the issues that still need to be addressed before liquid biopsies can be implemented in routine clinical practice for OC management.
Publisher: Springer Science and Business Media LLC
Date: 28-07-2023
DOI: 10.1007/S00432-022-04202-Y
Abstract: Circulating tumour cells (CTCs) are attractive “liquid biopsy” candidates that could provide insights into the different phenotypes of tumours present within a patient. The epithelial-to-mesenchymal transition (EMT) of CTCs is considered a critical step in tumour metastasis however, it may confound traditional epithelial feature-based CTC isolation and detection. We applied single-cell copy number alteration (CNA) analysis for the identification of genomic alterations to confirm the neoplastic nature of circulating cells with only mesenchymal phenotypes. We isolated CTCs from blood s les collected from 46 NSCLC patients using the Parsortix system. Enriched cells were subjected to immunofluorescent staining for CTC identification using a multi-marker panel comprising both epithelial and mesenchymal markers. A subset of isolated CTCs was subjected to whole genome lification (WGA) and low-pass whole-genome sequencing (LP-WGS) for the analysis of copy number alterations (CNAs). CTCs were detected in 16/46 (34.8%) patients, inclusive of CK + /EpCAM + CTCs (3/46, 6.5%) and Vim + CTCs (13/46, 28.3%). Clusters of Vim + cells were detected in 8 s les, which constitutes 50% of the total number of NSCLC patients with CTCs. No patients had detectable hybrid CK + /EpCAM + /Vim + cells. All of the tested CK + /EpCAM + CTCs and 7/8 Vim + CTCs or CTC clusters carried CNAs confirming their neoplastic nature. Notably, the Vim + cluster with no CNAs was characterised by spindle morphology and, therefore, defined as normal mesenchymal circulating cells. Our results revealed that CK-negative, vimentin-expressing cells represent a large proportion of CTCs detected in NSCLC patients, which are likely missed by standard epithelial-marker-dependent CTC categorisation.
Publisher: Hindawi Limited
Date: 2018
DOI: 10.1155/2018/1564150
Abstract: The prognosis of gastric and oesophageal adenocarcinoma remains generally poor. However, mounting evidence suggests a positive role of human epidermal growth factor receptor-2 (HER-2) expression in the prognosis of patients with these cancers. In this work, the patterns of HER-2 protein expression were determined in patients with gastric or oesophageal adenocarcinoma. Retrospectively, we reviewed records of gastric and oesophageal biopsies received from 2008 to 2012 and their corresponding archived formalin-fixed paraffin-embedded tissue blocks selected for immunohistochemical analysis. The prevalence of gastric and oesophageal adenocarcinomas and their association with HER-2 protein overexpression were evaluated. Gastric adenocarcinoma made up 18.79% of the gastric biopsies reviewed, and majority of these cancers occurred in males. Regarding the tumour type, HER-2 overexpression was common in the intestinal subtype compared to the diffuse type. Although squamous cell carcinoma was observed to be the commonest (31%) tumour type in the oesophagus compared to adenocarcinoma (8.79%), HER-2 was overexpressed in 42.9% of oesophageal adenocarcinomas, like gastric adenocarcinoma (41.4%). There is a high prevalence of gastric and oesophageal adenocarcinoma, with significant overexpression of HER-2 in these tumours, a window of hope for the management of patients with these cancers.
No related grants have been discovered for Du-Bois Asante.