50 research outputs found
Prevention and combat of a spillage after Ghana\u27s oil and gas discovery: is Ghana ready to face an environmental threat?
Effect of Drying Methods on Physicochemical Properties of Pretreated Tomato (lycopersicon esculentum mill.) Slices
The effect of drying methods on the physicochemical properties of white vinegar and sodium chloride/white vinegar mixture pre-treated
tomato slices was studied at drying temperatures of 45 and 55 oC. The physicochemical parameters investigated included pH, titratable acidity, total soluble solids, taste index, as well as colour and browning index. Signifi cantly higher moisture was removed in the treated samples than the control one. The dried tomato slices had higher titratable acidity but lower total soluble solids compared to the fresh sample. At 45 oC the titratable acidity for treated samples was signifi cantly higher (p<0.05) than that of the control. However, the pH of the control sample was significantly higher (p<0.05) than the treated ones. With the exception of the sodium chloride/ white vinegar treated samples, the other two samples experienced a reduction in total soluble solids with increasing drying temperature. The brix/acidity index or taste index of the treatments were signifi cantly higher (p<0.05) at 45 oC than at 55 oC. The control recorded a signifi cantly higher taste index value at 45 oC but signifi cantly
lower value at 55 oC than the pre-treated samples. The control experienced the least colour quality change but gave the highest browning index value. The sodium chloride/ white vinegar mixture was much effective in reducing browning process compared to the pre-treatment with white vinegar
A meaning-making perspective on digital ridesharing platforms in underdeveloped markets
Purpose: The digital platform-based sharing economy has become ubiquitous all over the world. In this paper, we explore how market actorsâ conflicting interpretations of digital platformsâ business models give form and shape value co-creation and capture practices in contexts marked by weak institutions and underdeveloped markets. Design/methodology/approach: Integrating insights from the broader literature on digital platforms and the contemporary turn to âmeaning-makingâ in social theory, we adopt a problematization method to unpack the collective contest over the interpretation of value co-creation and capture from ridesharing platforms in contexts marked by weak institutions and underdeveloped markets. Findings: Collective contest over the interpretation of digital business models may give rise to competing meanings that may enable (or impede) digital platform providersâ ability to co-create and capture value. We present an integrative framework that delineates how firms caught up in such collective contests in contexts marked by weak institutions and underdeveloped markets may utilise such conditions as marketing resources to reset their organising logic in ways that reconcile the conflicting perspectives. Practical implications: The paper presents propositions constituting a contribution to a meaning-making perspective on ridesharing digital platforms by offering insights into how digital business models could potentially be localised and adapted to address and align with the peculiarities of contexts. It goes further to present a theoretical model to extend our understanding of the different sources of contestation of meaning of digital platforms. Originality/value: The meaning-making perspective on digital platforms extends our understanding of how the collective contest over interpretations of value co-creation and capture may offer a set of contradictory frames that yield possibilities for ridesharing platform providers, and their users, to assimilate the organising logic of digital business models into new categories of understanding
Cytokine response to selected MTB antigens in Ghanaian TB patients, before and at 2 weeks of anti-TB therapy is characterized by high expression of IFN-gamma and Granzyme B and inter- individual variation
Background: There has been a long held belief that patients with drug-susceptible TB are non-infectious after two weeks of therapy. Recent microbiological and epidemiological evidence has challenged this dogma, however, the nature of the Mtb-specific cellular immune response during this period has not been adequately investigated. This knowledge could be exploited in the development of immunological biomarkers of early treatment response. Methods: Cellular response to four Mtb infection phase-dependent antigens, ESAT-6/CFP-10 fusion protein and three DosR encoded proteins (Rv1733c, Rv2029c, Rv2628) were evaluated in a Ghanaian TB cohort (n=20) before and after 2 weeks of anti TB therapy. After 6-days in vitro stimulation, Peripheral blood mononuclear cell (PBMC) culture supernatant was harvested and the concentration of IFN-gamma, Granzyme B, IL-10, IL-17, sIL2R alpha and TNF-alpha were determined in a 6-plex Luminex assay. Frequencies of IFN-gamma + CD4 and CD8 T cells were also determined in an intracellular cytokine assay. Results: All antigens induced higher levels of IFN-gamma, followed by Granzyme B, TNF-alpha and IL-17 and low levels of IL-10 and sIL-2R-alpha in PBMC before treatment and after 2 weeks of treatment. Median cytokine levels of IFN-gamma, Granzyme B, IL-17 and sIL-2R-alpha increased during week two, but it was significant for only Rv1733-specific production of Granzyme B (P = 0.013). The median frequency of antigen specific IFN-gamma + CD4 T cells increased at week two; however, only the increase in the ESAT-6/CFP-10-specific response was significant (P = 0.0008). In contrast, the median frequency of ESAT-6/CFP-10-specific IFN-gamma + CD8 T cell responses declined during week two (P = 0.0024). Additionally, wide inter-individual variation with three distinct patterns were observed; increase in all cytokine levels, decrease in all cytokine levels and fluctuating cytokine levels after 2 weeks of treatment. Conclusion: The second week of effective chemotherapy was characterized by a general increase in cytokine response to Mtb-specific antigens suggestive of an improvement in cellular response with therapy. However, the wide inter-individual variation observed would limit the utility of cytokine biomarkers during this period
UTILITY OF FIBEROPTIC BRONCHOSCOPY FOR RETRIEVAL OF ASPIRATED HEADSCARF PINS
Background: Tracheobronchial foreign body aspiration is a worldwide health problem which often results in life threatening complications.Headscarf pin aspiration is a common and unique form of foreign body aspiration among young Muslim women. Rigid bronchoscopy (RB) is considered the standard procedure for retrieval. Standard flexible bronchoscopy (FOB) is used increasingly in the treatment of tracheobronchial headscarf pins aspiration in adults.Aim: The aim of this study is to evaluate the utility (use) of FOB for the retrieval (extraction) of aspirated headscarf pins.Materials and Methods: Patients with the diagnosis of headscarf pin aspiration admitted to Sulaimanyah Teaching Hospital, department of cardiothoracic and vascular Surgery from January 2008 to September 2011 were included in the study. Standard FOB procedure using an oral approach with patient in recumbent position, under local anesthesia and conscious sedation was performed as the primary tool for retrieval.Results: A total of 20 cases were admitted during the study period. The mean age of the sample was 24 years (10-40 years).All patients presented with cough while two of them had hemoptysis (10%) and five had unilateral wheeze on chest auscultation (25%). The aspirated pin was successfully retrieved in 19/20 cases (95%) during the first attempt of FOB. However, FOB was not successful in 1/20 case (5%). The aspirated pin was successfully retrieved by RB under general anesthesia.Conclusions: FOB is a safe and successful method when performed by an experienced bronchoscopist, well educated staff, and at a well equipped bronchoscopy unit. Headscarf pin aspiration is a relatively common form of foreign body aspiration among young Muslim Iraqi women. It commonly occurs when women hold the pins in their teeth while wearing the hejaab and talking to others at the same time
Methicillin Resistant Staphylococcus aureus Transmission in a Ghanaian Burn Unit:The Importance of Active Surveillance in Resource-Limited Settings
Objectives:Staphylococcus aureus infections in burn patients can lead to serious complications and death. The frequency of S. aureus infection is high in low- and middle-income countries presumably due to limited resources, misuse of antibiotics and poor infection control. The objective of the present study was to apply population genomics to precisely define, for the first time, the transmission of antibiotic resistant S. aureus in a resource-limited setting in sub-Saharan Africa.Methods:Staphylococcus aureus surveillance was performed amongst burn patients and healthcare workers during a 7-months survey within the burn unit of the Korle Bu Teaching Hospital in Ghana.Results: Sixty-six S. aureus isolates (59 colonizing and 7 clinical) were obtained from 31 patients and 10 healthcare workers. Twenty-one of these isolates were ST250-IV methicillin-resistant S. aureus (MRSA). Notably, 25 (81%) of the 31 patients carried or were infected with S. aureus within 24 h of admission. Genome comparisons revealed six distinct S. aureus clones circulating in the burn unit, and demonstrated multiple transmission events between patients and healthcare workers. Further, the collected S. aureus isolates exhibited a wide range of genotypic resistances to antibiotics, including trimethoprim (21%), aminoglycosides (33%), oxacillin (33%), chloramphenicol (50%), tetracycline (59%) and fluoroquinolones (100%).Conclusion: Population genomics uncovered multiple transmission events of S. aureus, especially MRSA, within the investigated burn unit. Our findings highlight lapses in infection control and prevention, and underscore the great importance of active surveillance to protect burn victims against multi-drug resistant pathogens in resource-limited settings
Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients
Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like alpha-hemolysin, and the a and beta-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (ECG) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply That the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing
Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer
BACKGROUND:Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. METHODOLOGY:This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+) software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. PRINCIPAL FINDINGS:SeqSphere(+) analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus
Basic science232.âCertolizumab pegol prevents pro-inflammatory alterations in endothelial cell function
Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia Âź; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-ÎșB localization and IÎșB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-ÎșB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-ÎșB and degradation of IÎșB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-ÎșB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes