23 research outputs found

    Investigation of the chemical composition and biological activity of Xylopia aethiopica Dunal (Annonacae)

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    The phytochemical composition and physicochemical properties of oil extractable from the fruits of Xylopia aethiopica were determined. Extracts’ effects on cell membrane stability and prostaglandin synthetase activity were also evaluated. X. aethiopica oil extracted with chloroform: methanol (2:1, v/v) mixture contained carbohydrates, glycosides, flavonoids, saponins, tannins and phytosterols. The characteristic volatile and sweet smelling nature of X. aethiopica was predominantly inherent in this fraction. The sterol content was 64.30 mg/100 ml; with a high degree of unsaturatedness as evident in its high iodine value (85.76). High pressure liquid chromatographic analysis of the lipid extract revealed a fatty acid profile of palmitic acid (19.21%), palmitoleic acid (0.81%), stearic acid (4.54%), oleic acid (39.12%), linoleic acid (25.98%) and linolenic acid (1.10%). Investigation of the effect of the extract on hypotonicity- induced haemolysis of human red blood cells produced by water showed that the methanol extract of X. aethiopica (XAME) stabilized the red blood cells against the haemolytic action of distilled water. The lipid extract, on the other hand did not show any protective action against the osmotic shock. Xylopia aethiopica fruits may therefore be helpful in the maintenance of the integrity of the cellular membranes. The lipid extract also, in vitro, exhibited a prostaglandin synthetase substrate activity, whereas the methanol extract enhanced the synthesis of prostaglandins using X. aethiopica oil as  substrate. The presence of appreciable quantity of unsaturated fatty acids, stabilization of the cellular membrane integrity, promotion of the  biosynthesis of the hormone-like substances, prostaglandins, may be responsible for the usefulness of X. aethiopica fruits in the healing of wounds, inflammatory disorders and treatment of post-natal pains.Key words: Xylopia, linoleic acid, membranes, haemolysis, pains

    The Effects of Gray Markets in the International Product Distribution Systems

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    The problem of gray markets has become one of the main concerns to many global marketing firms. Many of the distribution goals of today’s firms in the international arena have been thwarted by the activities and issues of gray marketing. This work, therefore, analyzes the incidence of gray markets in the international distribution system. The study is guided by the following objectives: to examine if gray marketing  affects product defection as well as encourage increasing customers’ complaint; to examine the effects of gray markets activities on the availability of goods in certain part of the world; and to ascertain whether the realization of distribution objectives in the international marketing environment is affected by the incidence of gray market. To achieve the objectives spelled out, the study utilizes descriptive research. The questionnaire was the main research instrument that the study used to sift data from a sample of 50 respondents who were consumers. Based on the analyzed data, the following findings were made: that gray market  affects product defection and hence, it leads to increasing customer complaints of certain product in the foreign markets; that gray market leads to negative  availability of good in certain parts of the world; and that, gray market affects the realization of distribution goals and objectives of some organizations in international marketing environments.  Guided by the findings, the study concludes that gray markets have a very strong effect on the international distribution Systems, causing dumping of good in certain target foreign markets and leading to non-realization of place utility objective by some global firms. The study recommends that gray markets should be minimized through utilization of internet technology, lowering costs to reliable distributors and as well ensuring effective selection of middlemen. Keywords: gray market, distribution, international systems and parallel importing

    Authentication and characterisation of a new oesophageal adenocarcinoma cell line: MFD-1.

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    New biological tools are required to understand the functional significance of genetic events revealed by whole genome sequencing (WGS) studies in oesophageal adenocarcinoma (OAC). The MFD-1 cell line was isolated from a 55-year-old male with OAC without recombinant-DNA transformation. Somatic genetic variations from MFD-1, tumour, normal oesophagus, and leucocytes were analysed with SNP6. WGS was performed in tumour and leucocytes. RNAseq was performed in MFD-1, and two classic OAC cell lines FLO1 and OE33. Transposase-accessible chromatin sequencing (ATAC-seq) was performed in MFD-1, OE33, and non-neoplastic HET1A cells. Functional studies were performed. MFD-1 had a high SNP genotype concordance with matched germline/tumour. Parental tumour and MFD-1 carried four somatically acquired mutations in three recurrent mutated genes in OAC: TP53, ABCB1 and SEMA5A, not present in FLO-1 or OE33. MFD-1 displayed high expression of epithelial and glandular markers and a unique fingerprint of open chromatin. MFD-1 was tumorigenic in SCID mouse and proliferative and invasive in 3D cultures. The clinical utility of whole genome sequencing projects will be delivered using accurate model systems to develop molecular-phenotype therapeutics. We have described the first such system to arise from the oesophageal International Cancer Genome Consortium project.Cancer Research UK, Medical Research CouncilThis is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/srep3241

    Mutational signatures in esophageal adenocarcinoma define etiologically distinct subgroups with therapeutic relevance

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    Esophageal adenocarcinoma (EAC) has a poor outcome, and targeted therapy trials have thus far been disappointing owing to a lack of robust stratification methods. Whole-genome sequencing (WGS) analysis of 129 cases demonstrated that this is a heterogeneous cancer dominated by copy number alterations with frequent large-scale rearrangements. Co-amplification of receptor tyrosine kinases (RTKs) and/or downstream mitogenic activation is almost ubiquitous; thus tailored combination RTK inhibitor (RTKi) therapy might be required, as we demonstrate in vitro. However, mutational signatures showed three distinct molecular subtypes with potential therapeutic relevance, which we verified in an independent cohort (n = 87): (i) enrichment for BRCA signature with prevalent defects in the homologous recombination pathway; (ii) dominant T>G mutational pattern associated with a high mutational load and neoantigen burden; and (iii) C>A/T mutational pattern with evidence of an aging imprint. These subtypes could be ascertained using a clinically applicable sequencing strategy (low coverage) as a basis for therapy selection

    Multicentre cohort study to define and validate pathological assessment of response to neoadjuvant therapy in oesophagogastric adenocarcinoma

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    BACKGROUND: This multicentre cohort study sought to define a robust pathological indicator of clinically meaningful response to neoadjuvant chemotherapy in oesophageal adenocarcinoma. METHODS: A questionnaire was distributed to 11 UK upper gastrointestinal cancer centres to determine the use of assessment of response to neoadjuvant chemotherapy. Records of consecutive patients undergoing oesophagogastric resection at seven centres between January 2000 and December 2013 were reviewed. Pathological response to neoadjuvant chemotherapy was assessed using the Mandard Tumour Regression Grade (TRG) and lymph node downstaging. RESULTS: TRG (8 of 11 centres) was the most widely used system to assess response to neoadjuvant chemotherapy, but there was discordance on how it was used in practice. Of 1392 patients, 1293 had TRG assessment; data were available for clinical and pathological nodal status (cN and pN) in 981 patients, and TRG, cN and pN in 885. There was a significant difference in survival between responders (TRG 1–2; median overall survival (OS) not reached) and non-responders (TRG 3–5; median OS 2·22 (95 per cent c.i. 1·94 to 2·51) years; P < 0·001); the hazard ratio was 2·46 (95 per cent c.i. 1·22 to 4·95; P = 0·012). Among local non-responders, the presence of lymph node downstaging was associated with significantly improved OS compared with that of patients without lymph node downstaging (median OS not reached versus 1·92 (1·68 to 2·16) years; P < 0·001). CONCLUSION: A clinically meaningful local response to neoadjuvant chemotherapy was restricted to the small minority of patients (14·8 per cent) with TRG 1–2. Among local non-responders, a subset of patients (21·3 per cent) derived benefit from neoadjuvant chemotherapy by lymph node downstaging and their survival mirrored that of local responders

    Strengthening retinopathy of prematurity screening and treatment services in Nigeria: a case study of activities, challenges and outcomes 2017-2020.

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    OBJECTIVES: Retinopathy of prematurity (ROP) will become a major cause of blindness in Nigerian children unless screening and treatment services expand. This article aims to describe the collaborative activities undertaken to improve services for ROP between 2017 and 2020 as well as the outcome of these activities in Nigeria. DESIGN: Descriptive case study. SETTING: Neonatal intensive care units in Nigeria. PARTICIPANTS: Staff providing services for ROP, and 723 preterm infants screened for ROP who fulfilled screening criteria (gestational age <34 weeks or birth weight ≤2000 g, or sickness criteria). METHODS AND ANALYSIS: A WhatsApp group was initiated for Nigerian ophthalmologists and neonatologists in 2018. Members participated in a range of capacity-building, national and international collaborative activities between 2017 and 2018. A national protocol for ROP was developed for Nigeria and adopted in 2018; 1 year screening outcome data were collected and analysed. In 2019, an esurvey was used to collect service data from WhatsApp group members for 2017-2018 and to assess challenges in service provision. RESULTS: In 2017 only six of the 84 public neonatal units in Nigeria provided ROP services; this number had increased to 20 by 2018. Of the 723 babies screened in 10 units over a year, 127 (17.6%) developed any ROP; and 29 (22.8%) developed type 1 ROP. Only 13 (44.8%) babies were treated, most by intravitreal bevacizumab. The screening criteria were revised in 2020. Challenges included lack of equipment to regulate oxygen and to document and treat ROP, and lack of data systems. CONCLUSION: ROP screening coverage and quality improved after national and international collaborative efforts. To scale up and improve services, equipment for neonatal care and ROP treatment is urgently needed, as well as systems to monitor data. Ongoing advocacy is also essential

    Authentication and characterisation of a new oesophageal adenocarcinoma cell line: MFD-1

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    New biological tools are required to understand the functional significance of genetic events revealed by whole genome sequencing (WGS) studies in oesophageal adenocarcinoma (OAC). The MFD-1 cell line was isolated from a 55-year-old male with OAC without recombinant-DNA transformation. Somatic genetic variations from MFD-1, tumour, normal oesophagus, and leucocytes were analysed with SNP6. WGS was performed in tumour and leucocytes. RNAseq was performed in MFD-1, and two classic OAC cell lines FLO1 and OE33. Transposase-accessible chromatin sequencing (ATAC-seq) was performed in MFD-1, OE33, and non-neoplastic HET1A cells. Functional studies were performed. MFD-1 had a high SNP genotype concordance with matched germline/tumour. Parental tumour and MFD-1 carried four somatically acquired mutations in three recurrent mutated genes in OAC: TP53, ABCB1 and SEMA5A, not present in FLO-1 or OE33. MFD-1 displayed high expression of epithelial and glandular markers and a unique fingerprint of open chromatin. MFD-1 was tumorigenic in SCID mouse and proliferative and invasive in 3D cultures. The clinical utility of whole genome sequencing projects will be delivered using accurate model systems to develop molecular-phenotype therapeutics. We have described the first such system to arise from the oesophageal International Cancer Genome Consortium project

    Transcriptomic profiling reveals three molecular phenotypes of adenocarcinoma at the gastroesophageal junction

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    Cancers occurring at the gastroesophageal junction (GEJ) are classified as predominantly esophageal or gastric, which is often difficult to decipher. We hypothesized that the transcriptomic profile might reveal molecular subgroups which could help to define the tumor origin and behavior beyond anatomical location. The gene expression profiles of 107 treatment‐naïve, intestinal type, gastroesophageal adenocarcinomas were assessed by the Illumina‐HTv4.0 beadchip. Differential gene expression (limma), unsupervised subgroup assignment (mclust) and pathway analysis (gage) were undertaken in R statistical computing and results were related to demographic and clinical parameters. Unsupervised assignment of the gene expression profiles revealed three distinct molecular subgroups, which were not associated with anatomical location, tumor stage or grade (p > 0.05). Group 1 was enriched for pathways involved in cell turnover, Group 2 was enriched for metabolic processes and Group 3 for immune‐response pathways. Patients in group 1 showed the worst overall survival (p = 0.019). Key genes for the three subtypes were confirmed by immunohistochemistry. The newly defined intrinsic subtypes were analyzed in four independent datasets of gastric and esophageal adenocarcinomas with transcriptomic data available (RNAseq data: OCCAMS cohort, n = 158; gene expression arrays: Belfast, n = 63; Singapore, n = 191; Asian Cancer Research Group, n = 300). The subgroups were represented in the independent cohorts and pooled analysis confirmed the prognostic effect of the new subtypes. In conclusion, adenocarcinomas at the GEJ comprise three distinct molecular phenotypes which do not reflect anatomical location but rather inform our understanding of the key pathways expressed
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