13 research outputs found

    Introduction: Forensic Fail

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    Background: About 60% of Pheochromocytoma (PCC) and Paraganglioma (PGL) patients have either germline or somatic mutations in one of the 12 proposed disease causing genes; SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, EPAS1, RET, NF1, TMEM127, MAX and H-RAS. Selective screening for germline mutations is routinely performed in clinical management of these diseases. Testing for somatic alterations is not performed on a regular basis because of limitations in interpreting the results. Aim: The purpose of the study was to investigate genetic events and phenotype correlations in a large cohort of PCC and PGL tumours. Methods: A total of 101 tumours from 89 patients with PCC and PGL were re-sequenced for a panel of 10 disease causing genes using automated Sanger sequencing. Selected samples were analysed with Multiplex Ligation-dependent Probe Amplification and/or SNParray. Results: Pathogenic genetic variants were found in tumours from 33 individual patients (37%), 14 (16%) were discovered in constitutional DNA and 16 (18%) were confirmed as somatic. Loss of heterozygosity (LOH) was observed in 1/1 SDHB, 11/11 VHL and 3/3 NF1-associated tumours. In patients with somatic mutations there were no recurrences in contrast to carriers of germline mutations (P = 0.022). SDHx/VHL/ EPAS1 associated cases had higher norepinephrine output (P = 0.03) and lower epinephrine output (P<0.001) compared to RET/NF1/H-RAS cases. Conclusion: Somatic mutations are frequent events in PCC and PGL tumours. Tumour genotype may be further investigated as prognostic factors in these diseases. Growing evidence suggest that analysis of tumour DNA could have an impact on the management of these patients

    Maculosin, a non-toxic antioxidant compound isolated from Streptomyces sp. KTM18

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    Context Streptomyces species are prolific sources of bioactive secondary metabolites known especially for their antimicrobial and anticancer activities. Objective This study sought to isolate and characterize antioxidant molecules biosynthesized by Streptomyces sp. KTM18. The antioxidant potential of an isolated compound and its toxicity were accessed. Materials and methods The compound was purified using bioassay-guided chromatography techniques. Nuclear magnetic resonance (NMR) experiments were carried out for structure elucidation. The antioxidant potential of the isolated compound was determined using DPPH free radical scavenging assay. The toxicity of the isolated compound was measured using a brine shrimp lethality (BSL) assay. Results Ethyl acetate extract of Streptomyces sp. KTM18 showed more than 90% inhibition of DPPH free radical at 50 mu g/mL of the test concentration. These data were the strongest among 13 Streptomyces isolates (KTM12-KTM24). The active molecule was isolated and characterized as maculosin (molecular formula, C14H16N2O3 as determined by the [M + H](+) peak at 261.1259). The DPPH free radical scavenging activity of pure maculosin was higher (IC50, 2.16 +/- 0.05 mu g/mL) than that of commercial butylated hydroxyanisole (BHA) (IC50, 4.8 +/- 0.05 mu g/mL). No toxicity was observed for maculosin (LD50, <128 mu g/mL) in brine shrimp lethality assay (BSLA) up to the compound's antioxidant activity (IC50) concentration range. The commercial standard, berberine chloride, showed toxicity in BSLA with an LD50 value of 8.63 +/- 0.15 mu g/mL. Conclusions Maculosin may be a leading drug candidate in various cosmetic and therapeutic applications owing to its strong antioxidant and non-toxic properties

    New Insights in Adrenal Tumourigenesis.

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    Unilateral cortisol producing adenoma (CPA) is the most common cause of ACTH-independent Cushing’s syndrome and is surgically curable. On the other hand, adrenocortical carcinomas (ACCs) are rare and aggressive tumours. Although the overall survival of the patients with ACC is very poor, the outcome can be heterogeneous and vary significantly between the patients. This thesis comprises studies showing genetic and genomic events occurring in CPAs and ACCs, their functional impact and clinical correlations. The Wnt/β-catenin and cAMP/PKA signalling pathways are crucial in adrenal homeostasis and frequent mutations in members of these pathways (CTNNB1, GNAS, and PRKACA) are found in CPAs. Mutational analysis revealed that ~60% of the CPAs harboured mutations in either of these genes. Transcriptome signature exhibited increased expression of genes involved in steroidogenesis in PRKACA/GNAS mutated (Cluster1) tumours in comparison to CTNNB1 mutated /wildtype (Cluster2) tumours. In addition we have also observed that gain of chromosome arm 9q was the most frequent arm level copy number variation (CNV) occurring in CPAs and were exclusively present in Cluster2 tumours. We also discovered novel PRKACA mutations occurring in ACCs, causing activation of cAMP/signalling pathway.    Comprehensive analysis of Wnt/β-catenin signalling pathway in ACCs revealed novel interstitial deletions occurring in CTNNB1 leading to deletion of the N-terminus of β-catenin. This is a novel and yet another frequent event leading to activated Wnt/β-catenin signalling and downstream targets in ACCs. Both, mutations occurring in CTNNB1 and nuclear expression of its protein were associated with poor overall survival. Through multiregional sampling approach we discovered intra-tumour heterogeneity in ACC tumours. Although all the multiregions within a tumour showed presence of shared basal CNVs, they encompassed private CNVs, different ploidy levels and private mutations in known driver genes. We found intra-tumour heterogeneity in CTNNB1, PRKACA, TERT promoter and TP53 mutations as well as ZNRF3 and CDKN2A/2B homozygous deletions

    Supporting self-care in prevention of stroke disease through patient education

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    Stroke is a medical emergency that on occurrence proceeds to mortality or physical disability. Self-care is a profound tool in prevention of stroke disease. Nurses are in an ideal position to play a vital role in ongoing patient education about risk factors, signs and symptoms, and hence assist in prevention of stroke disease among adult population. The aim of this thesis was to enhance knowledge on the prevention of stroke disease through patient education. Systematic literature review was applied to conduct the study. The online databases that were systematically searched included Cinahl, Ebsco and Sage. A total 24 articles were pertinent to the thesis topic. Inductive content analysis was used to analyse the data gathered from these articles. In addition, inclusion and exclusion criteria were used to key out the information relevant in answering the research question in thesis. The research questions of this thesis were: What information is relevant in prevention of stroke disease? What is the benefit of patient education? The study resulted into a number of themes in relation to supporting self-care in prevention of stroke which includes; various aspects of prevention, patient education methods and risk factors of stroke disease. This thesis can empower nurses on how to appropriately educate the patients on prevention of stoke disease through enrichment of knowledge on risk factors and pathophysiology of the disease

    Comprehensive analysis of CTNNB1 in adrenocortical carcinomas : Identification of novel mutations and correlation to survival

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    The Wnt/β-Catenin signaling pathway is one of the most frequently altered pathways in adrenocortical carcinomas (ACCs). The aim of this study was to investigate the status of Wnt/β-Catenin signaling pathway by analyzing the expression level of β-Catenin and the mutational status of APC, AXIN2, CTNNB1, and ZNRF3 in ACCs. Mutations in APC, CTNNB1, ZNRF3 and homozygous deletions in ZNRF3 were observed in 3.8% (2/52), 11.5% (6/52), 1.9% (1/52) and 17.3% (9/52) of the cohort respectively. Novel interstitial deletions in CTNNB1 spanning intron 1 to exon 3/intron 3 were also found in 7.7% (4/52) of the tumours. All the observed alterations were mutually exclusive. Nuclear accumulation of β-Catenin, increased expression of Cyclin D1 and significantly higher expression of AXIN2 (p = 0.0039), ZNRF3 (p = 0.0032) and LEF1(p = 0.0090) observed in the tumours harbouring the deletion in comparison to tumours without CTNNB1 mutation demonstrates that the truncated β-Catenin is functionally active and erroneously activates the downstream targets. Significantly lower overall survival rate in patients with tumours harbouring alterations in APC/CTNNB1/ZNRF3 in comparison to those without mutation was observed. In conclusion, the discovery of novel large deletions in addition to the point mutations in CTNNB1 infers that activation of Wnt/β-Catenin pathway via alterations in CTNNB1 occurs frequently in ACCs. We also confirm that alterations in Wnt/β-Catenin signaling pathway members have a negative effect on overall survival of patients

    Risk of Handling Paper Currency in Circulation Chances of Potential Bacterial Transmittance

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    All sets of paper currency produced by the government of Nepal were collected from four major sources (transporters, butchers, food sellers, and banks) where paper currency is widely used. The currencies used by public transport in Nepal (micro-buses) were found to be extremely contaminated with various pathogenic bacteria followed by the currency used by butchers and food sellers. These microorganisms could be one of the major causes of widely transmitting diseases in Nepal. Eight different pathogenic bacteria were isolated that are the known to be involved in transmitting various diseases in Nepal. A lot of people loss their life every year in Nepal due to the transmittance of diseases by these kind of bacteria. Use of paper money could be one of the major sources of transmittance of such diseases in Nepal that provides platform for the growth of such bacteria. Public awareness of using paper currency in circulation became essential for the safety in human health. Key words: Escherichia coli, infections, pathogens, Staphylococcus aureus, Salmonella choleraesiu

    Integrative Genetic Characterization and Phenotype Correlations in Pheochromocytoma and Paraganglioma Tumours

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    Background: About 60% of Pheochromocytoma (PCC) and Paraganglioma (PGL) patients have either germline or somatic mutations in one of the 12 proposed disease causing genes; SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, EPAS1, RET, NF1, TMEM127, MAX and H-RAS. Selective screening for germline mutations is routinely performed in clinical management of these diseases. Testing for somatic alterations is not performed on a regular basis because of limitations in interpreting the results. Aim: The purpose of the study was to investigate genetic events and phenotype correlations in a large cohort of PCC and PGL tumours. Methods: A total of 101 tumours from 89 patients with PCC and PGL were re-sequenced for a panel of 10 disease causing genes using automated Sanger sequencing. Selected samples were analysed with Multiplex Ligation-dependent Probe Amplification and/or SNParray. Results: Pathogenic genetic variants were found in tumours from 33 individual patients (37%), 14 (16%) were discovered in constitutional DNA and 16 (18%) were confirmed as somatic. Loss of heterozygosity (LOH) was observed in 1/1 SDHB, 11/11 VHL and 3/3 NF1-associated tumours. In patients with somatic mutations there were no recurrences in contrast to carriers of germline mutations (P = 0.022). SDHx/VHL/ EPAS1 associated cases had higher norepinephrine output (P = 0.03) and lower epinephrine output (P&lt;0.001) compared to RET/NF1/H-RAS cases. Conclusion: Somatic mutations are frequent events in PCC and PGL tumours. Tumour genotype may be further investigated as prognostic factors in these diseases. Growing evidence suggest that analysis of tumour DNA could have an impact on the management of these patients

    RNA Sequencing Provides Novel Insights into the Transcriptome of Aldosterone Producing Adenomas

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    Aldosterone producing adenomas (APAs) occur in the adrenal glands of around 30% of patients with primary aldosteronism, the most common form of secondary hypertension. Somatic mutations in KCNJ5, ATP1A1, ATP2B3, CACNA1D and CTNNB1 have been described in similar to 60% of these tumours. We subjected 15 aldosterone producing adenomas (13 with known mutations and two without) to RNA Sequencing and Whole Genome Sequencing (n = 2). All known mutations were detected in the RNA-Seq reads, and mutations in ATP2B3 (G123R) and CACNA1D (S410L) were discovered in the tumours without known mutations. Adenomas with CTNNB1 mutations showed a large number of differentially expressed genes (1360 compared to 106 and 75 for KCNJ5 and ATP1A1/ATP2B3 respectively) and clustered together in a hierarchical clustering analysis. RT-PCR in an extended cohort of 49 APAs confirmed higher expression of AFF3 and ISM1 in APAs with CTNNB1 mutations. Investigation of the expression of genes involved in proliferation and apoptosis revealed subtle differences between tumours with and without CTNNB1 mutations. Together our results consolidate the notion that CTNNB1 mutations characterize a distinct subgroup of APAs.De två första författarna delar förstaförfattarskapet.</p

    Global DNA Methylation Analysis Identifies Two Discrete clusters of Pheochromocytoma with Distinct Genomic and Genetic Alterations

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    Pheochromocytomas and paragangliomas (PPGLs) are rare and frequently heritable neural-crest derived tumours arising from the adrenal medulla or extra-adrenal chromaffin cells respectively. The majority of PPGL tumours are benign and do not recur with distant metastases. However, a sizeable fraction of these tumours secrete vasoactive catecholamines into the circulation causing a variety of symptoms including hypertension, palpitations and diaphoresis. The genetic landscape of PPGL has been well characterized and more than a dozen genes have been described as recurrently mutated. Recent studies of DNA-methylation have revealed distinct clusters of PPGL that share DNA methylation patterns and driver mutations, as well as identified potential biomarkers for malignancy. However, these findings have not been adequately validated in independent cohorts. In this study we use an array-based genome-wide approach to study the methylome of 39 PPGL and 4 normal adrenal medullae. We identified two distinct clusters of tumours characterized by different methylation patterns and different driver mutations. Moreover, we identify genes that are differentially methylated between tumour subcategories, and between tumours and normal tissue

    Clinical characteristics and carrier status.

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    <p>Statistical correlation of clinical variables and carriers status. Multifocal tumours was defined as bilateral pheochromocytoma or multiple paraganglioma tumours.</p>*<p>Patients with no available germline DNA were excluded.</p>**<p>Included 14 germline variants and 4 patients with clinical criteria of Neurofibromatosis type 1.</p>***<p>Nine patients had metastatic disease, one of these had metastatic disease at the time of diagnosis and the remaining had metastatic recurrences later on in the disease course. §Mann-Whitney U Test and §§Chi Square test.</p
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