788 research outputs found
Novel APC promoter and exon 1B deletion and allelic silencing in three mutation-negative classic familial adenomatous polyposis families
BACKGROUND: The overwhelming majority (approximately 80%) of individuals with classic familial adenomatous polyposis (FAP) exhibit mutations in the coding sequence of the adenomatous polyposis coli (APC) tumor suppressor gene. Families without detectable APC mutations are unable to benefit from the use of genetic testing for clinical management of this autosomal dominant syndrome. METHODS: We used exome sequencing and linkage analysis, coupled with second-generation sequencing of the APC locus including non-coding regions to investigate three APC mutation-negative classical FAP families. RESULTS: We identified a novel ~11 kb deletion localized 44 kb upstream of the transcription start site of APC that encompasses the APC 1B promoter and exon. This deletion was present only in affected family members of one kindred with classical FAP. Furthermore, this same deletion with identical breakpoints was found in the probands of two additional APC mutation-negative classical FAP kindreds. Phasing analysis of single nucleotide polymorphisms (SNPs) around the deletion site in the three probands showed evidence of a shared haplotype, suggesting a common founder deletion in the three kindreds. SNP analysis within the coding sequence of APC, revealed that this ~11 kb deletion was accompanied by silencing of one of the APC alleles in blood-derived RNA of affected individuals. CONCLUSIONS: These results support the causal role of a novel promoter deletion in FAP and suggest that non-coding deletions, identifiable using second-generation sequencing methods, may account for a significant fraction of APC mutation-negative classical FAP families
MLH1-methylated endometrial cancer under 60 years of age as the “sentinel” cancer in female carriers of high-risk constitutional MLH1 epimutation
Objective. Universal screening of endometrial carcinoma (EC) for mismatch repair deficiency (MMRd) and Lynch syndrome uses presence of MLH1 methylation to omit common sporadic cases from follow-up germline testing. However, this overlooks rare cases with high-risk constitutional MLH1 methylation (epimutation), a poorly-recognized mechanism that predisposes to Lynch-type cancers with MLH1 methylation. We aimed to de-termine the role and frequency of constitutional MLH1 methylation among EC cases with MMRd, MLH1- methylated tumors.Methods. We screened blood for constitutional MLH1 methylation using pyrosequencing and real-time methylation-specific PCR in patients with MMRd, MLH1-methylated EC ascertained from (i) cancer clinics (n = 4, <60 years), and (ii) two population-based cohorts; Columbus-area (n = 68, all ages) and Ohio Colo-rectal Cancer Prevention Initiative (OCCPI) (n = 24, <60 years).Results. Constitutional MLH1 methylation was identified in three out of four patients diagnosed between 36 and 59 years from cancer clinics. Two had mono-/hemiallelic epimutation (similar to 50% alleles methylated). One with multiple primaries had low-level mosaicism in normal tissues and somatic second-hits affecting the unmethylated allele in all tumors, demonstrating causation. In the population-based cohorts, all 68 cases from the Columbus-area cohort were negative and low-level mosaic constitutional MLH1 methylation was identified in one patient aged 36 years out of 24 from the OCCPI cohort, representing one of six (similar to 17%) patients <50 years and one of 45 patients (similar to 2%) <60 years in the combined cohorts. EC was the first/dual-first cancer in three pa-tients with underlying constitutional MLH1 methylation.Conclusions. A correct diagnosis at first presentation of cancer is important as it will significantly alter clinical management. Screening for constitutional MLH1 methylation is warranted in patients with early-onset EC or syn-chronous/metachronous tumors (any age) displaying MLH1 methylation.(c) 2023 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/)
Multiple Sclerosis risk variants regulate gene expression in innate and adaptive immune cells
At least 200 single-nucleotide polymorphisms (SNPs) are associated with multiple sclerosis (MS) risk. A key function that could mediate SNP-encoded MS risk is their regulatory effects on gene expression. We performed microarrays using RNA extracted from purified immune cell types from 73 untreated MS cases and 97 healthy controls and then performed Cis expression quantitative trait loci mapping studies using additive linear models. We describe MS risk expression quantitative trait loci associations for 129 distinct genes. By extending these models to include an interaction term between genotype and phenotype, we identify MS risk SNPs with opposing effects on gene expression in cases compared with controls, namely, rs2256814 MYT1 in CD4 cells (q = 0.05) and rs12087340 RF00136 in monocyte cells (q = 0.04). The rs703842 SNP was also associated with a differential effect size on the expression of the METTL21B gene in CD8 cells of MS cases relative to controls (q = 0.03). Our study provides a detailed map of MS risk loci that function by regulating gene expression in cell types relevant to MS
Individual correlates of podoconiosis in areas of varying endemicity: a case-control study
BACKGROUND
Podoconiosis is a non-filarial form of elephantiasis resulting in lymphedema of the lower legs. Previous studies have suggested that podoconiosis arises from the interplay of individual and environmental factors. Here, our aim was to understand the individual-level correlates of podoconiosis by comparing 460 podoconiosis-affected individuals and 707 unaffected controls.
METHODS/PRINCIPAL FINDINGS
This was a case-control study carried out in six kebeles (the lowest governmental administrative unit) in northern Ethiopia. Each kebele was classified into one of three endemicity levels: 'low' (prevalence 5%). A total of 142 (30.7%) households had two or more cases of podoconiosis. Compared to controls, the majority of the cases, especially women, were less educated (OR = 1.7, 95% CI = 1.3 to 2.2), were unmarried (OR = 3.4, 95% CI = 2.6-4.6) and had lower income (t = -4.4, p<0.0001). On average, cases started wearing shoes ten years later than controls. Among cases, age of first wearing shoes was positively correlated with age of onset of podoconiosis (r = 0.6, t = 12.5, p<0.0001). Among all study participants average duration of shoe wearing was less than 30 years. Between both cases and controls, people in 'high' and 'medium' endemicity kebeles were less likely than people in 'low' endemicity areas to 'ever' have owned shoes (OR = 0.5, 95% CI = 0.4-0.7).
CONCLUSIONS
Late use of shoes, usually after the onset of podoconiosis, and inequalities in education, income and marriage were found among cases, particularly among females. There were clustering of cases within households, thus interventions against podoconiosis will benefit from household-targeted case tracing. Most importantly, we identified a secular increase in shoe-wearing over recent years, which may give opportunities to promote shoe-wearing without increasing stigma among those at high risk of podoconiosis
A targeted metabolomic protocol for short-chain fatty acids and branched-chain amino acids
Research in obesity and metabolic disorders that involve intestinal microbiota demands reliable methods for the precise measurement of the short-chain fatty acids (SCFAs) and branched-chain amino acids (BCAAs) concentration. Here, we report a rapid method of simultaneously determining SCFAs and BCAAs in biological samples using propyl chloroformate (PCF) derivatization followed by gas chromatography mass spectrometry (GC-MS) analysis. A one-step derivatization using 100 µL of PCF in a reaction system of water, propanol, and pyridine (v/v/v = 8:3:2) at pH 8 provided the optimal derivatization efficiency. The best extraction efficiency of the derivatized products was achieved by a two-step extraction with hexane. The method exhibited good derivatization efficiency and recovery for a wide range of concentrations with a low limit of detection for each compound. The relative standard deviations (RSDs) of all targeted compounds showed good intra- and inter-day (within 7 days) precision (< 10%), and good stability (< 20%) within 4 days at room temperature (23–25 °C), or 7 days when stored at −20 °C. We applied our method to measure SCFA and BCAA levels in fecal samples from rats administrated with different diet. Both univariate and multivariate statistics analysis of the concentrations of these target metabolites could differentiate three groups with ethanol intervention and different oils in diet. This method was also successfully employed to determine SCFA and BCAA in the feces, plasma and urine from normal humans, providing important baseline information of the concentrations of these metabolites. This novel metabolic profile study has great potential for translational research
Physical activity as a treatment for depression: the TREAD randomised trial protocol
Depression is one of the most common reasons for consulting a General Practitioner (GP) within the UK. Whilst antidepressants have been shown to be clinically effective, many patients and healthcare professionals would like to access other forms of treatment as an alternative or adjunct to drug therapy for depression. A recent systematic review presented some evidence that physical activity could offer one such option, although further investigation is needed to test its effectiveness within the context of the National Health Service.The aim of this paper is to describe the protocol for a randomised, controlled trial (RCT) designed to evaluate an intervention developed to increase physical activity as a treatment for depression within primary care
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
If you build it, they still may not come: outcomes and process of implementing a community-based integrated knowledge translation mapping innovation
<p>Abstract</p> <p>Background</p> <p>Maps and mapping tools through geographic information systems (GIS) are highly valuable for turning data into useful information that can help inform decision-making and knowledge translation (KT) activities. However, there are several challenges involved in incorporating GIS applications into the decision-making process. We highlight the challenges and opportunities encountered in implementing a mapping innovation as a KT strategy within the non-profit (public) health sector, reflecting on the processes and outcomes related to our KT innovations.</p> <p>Methods</p> <p>A case study design, whereby the case is defined as the data analyst and manager dyad (a two-person team) in selected Ontario Early Year Centres (OEYCs), was used. Working with these paired individuals, we provided a series of interventions followed by one-on-one visits to ensure that our interventions were individually tailored to personal and local decision-making needs. Data analysis was conducted through a variety of qualitative assessments, including field notes, interview data, and maps created by participants. Data collection and data analysis have been guided by the Ottawa Model of Research Use (OMRU) conceptual framework.</p> <p>Results</p> <p>Despite our efforts to remove all barriers associated with our KT innovation (maps), our results demonstrate that both individual level and systemic barriers pose significant challenges for participants. While we cannot claim a causal association between our project and increased mapping by participants, participants did report a moderate increase in the use of maps in their organization. Specifically, maps were being used in decision-making forums as a way to allocate resources, confirm tacit knowledge about community needs, make financially-sensitive decisions more transparent, evaluate programs, and work with community partners.</p> <p>Conclusions</p> <p>This project highlights the role that maps can play and the importance of communicating the importance of maps as a decision support tool. Further, it represents an integrated knowledge project in the community setting, calling to question the applicability of traditional KT approaches when community values, minimal resources, and partners play a large role in decision making. The study also takes a unique perspective--where research producers and users work as dyad-pairs in the same organization--that has been under-explored to date in KT studies.</p
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