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1.
Aging Ment Health ; 28(2): 197-206, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37667896

RESUMO

OBJECTIVES: Hospices are regarded as gold standard providers of end-of-life care. The term hospice, however, is broadly used, and can describe a type of care offered in a variety of health care services (e.g. nursing homes). It thus becomes complex for families to decide between services. We aimed to review the evidence around the experience of family carers of people with dementia accessing in-patient hospice settings for end-of-life care. METHOD: We registered the review protocol on PROSPERO. We used PerSPE(C)TiF to systematically organise our search strategy. The evidence was reviewed across six databases: PubMed, EMBASE, PsycINFO, ASSIA, ISI Web, and CINAHL. We used meta-ethnography as per the eMERGe guidance for data interpretation. RESULTS: Four studies were included. Two third-order constructs were generated through meta-ethnography: expectations of care and barriers to quality of care. We found that carers had expectations of care, and these could change over time. If discussion was not held with hospice staff early on, the carers could experience reduced care quality due to unmatched expectations. Unmatched expectations acted as barriers to care and these were found in terms of carers not feeling adequately supported, and/or having the person discharged from hospice, which would entail increased care responsibility for carers. CONCLUSION: In view of an increase in new dementia cases over time and with hospice services being under pressure, integrating palliative care services within community-based models of care is key to reducing the risk of having inadequate and under resourced services for people with dementia.


Assuntos
Demência , Hospitais para Doentes Terminais , Assistência Terminal , Humanos , Cuidadores , Antropologia Cultural , Demência/terapia
2.
Br J Surg ; 110(4): 471-480, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-36785496

RESUMO

BACKGROUND: Faecal immunochemical test (FIT)-directed pathways based on a single test have been implemented for symptomatic patients. However, with a single test, the sensitivity is 87 per cent at 10 µg haemoglobin (Hb) per g faeces. This aims of this study were to define the diagnostic performance of a single FIT, compared with double FIT in symptomatic populations. METHODS: Two sequential prospective patient cohorts referred with symptoms from primary care were studied. Patients in cohort 1 were sent a single FIT, and those in cohort 2 received two tests in succession before investigation. All patients were investigated, regardless of having a positive or negative test (threshold 10 µg Hb per g). RESULTS: In cohort 1, 2260 patients completed one FIT and investigation. The sensitivity of single FIT was 84.1 (95 per cent c.i. 73.3 to 91.8) per cent for colorectal cancer and 67.4 (61.0 to 73.4) per cent for significant bowel pathology. In cohort 2, 3426 patients completed at least one FIT, and 2637 completed both FITs and investigation. The sensitivity of double FIT was 96.6 (90.4 to 99.3) per cent for colorectal cancer and 83.0 (77.4 to 87.8) per cent for significant bowel pathology. The second FIT resulted in a 50.0 per cent reduction in cancers missed by the first FIT, and 30.0 per cent for significant bowel pathology. Correlation between faecal Hb level was only modest (rs = 0.58), and 16.8 per cent of double tests were discordant, 11.4 per cent in patients with colorectal cancer and 18.3 per cent in those with significant bowel pathology. CONCLUSION: FIT in patients with high-risk symptoms twice in succession reduces missed significant colorectal pathology and has an acceptable workload impact.


Assuntos
Neoplasias Colorretais , Humanos , Sensibilidade e Especificidade , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Estudos Prospectivos , Hemoglobinas/análise , Fezes/química , Sangue Oculto , Detecção Precoce de Câncer/métodos , Colonoscopia
3.
BMC Med ; 19(1): 174, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34340708

RESUMO

BACKGROUND: The risk for several common cancers is influenced by the transcriptomic landscape of the respective tissue-of-origin. Vitamin D influences in vitro gene expression and cancer cell growth. We sought to determine whether oral vitamin D induces beneficial gene expression effects in human rectal epithelium and identify biomarkers of response. METHODS: Blood and rectal mucosa was sampled from 191 human subjects and mucosa gene expression (HT12) correlated with plasma vitamin D (25-OHD) to identify differentially expressed genes. Fifty subjects were then administered 3200IU/day oral vitamin D3 and matched blood/mucosa resampled after 12 weeks. Transcriptomic changes (HT12/RNAseq) after supplementation were tested against the prioritised genes for gene-set and GO-process enrichment. To identify blood biomarkers of mucosal response, we derived receiver-operator curves and C-statistic (AUC) and tested biomarker reproducibility in an independent Supplementation Trial (BEST-D). RESULTS: Six hundred twenty-nine genes were associated with 25-OHD level (P < 0.01), highlighting 453 GO-term processes (FDR<0.05). In the whole intervention cohort, vitamin D supplementation enriched the prioritised mucosal gene-set (upregulated gene-set P < 1.0E-07; downregulated gene-set P < 2.6E-05) and corresponding GO terms (P = 2.90E-02), highlighting gene expression patterns consistent with anti-tumour effects. However, only 9 individual participants (18%) showed a significant response (NM gene-set enrichment P < 0.001) to supplementation. Expression changes in HIPK2 and PPP1CC expression served as blood biomarkers of mucosal transcriptomic response (AUC=0.84 [95%CI 0.66-1.00]) and replicated in BEST-D trial subjects (HIPK2 AUC=0.83 [95%CI 0.77-0.89]; PPP1CC AUC=0.91 [95%CI 0.86-0.95]). CONCLUSIONS: Higher plasma 25-OHD correlates with rectal mucosa gene expression patterns consistent with anti-tumour effects, and this beneficial signature is induced by short-term vitamin D supplementation. Heterogenous gene expression responses to vitamin D may limit the ability of randomised trials to identify beneficial effects of supplementation on CRC risk. However, in the current study blood expression changes in HIPK2 and PPP1CC identify those participants with significant anti-tumour transcriptomic responses to supplementation in the rectum. These data provide compelling rationale for a trial of vitamin D and CRC prevention using easily assayed blood gene expression signatures as intermediate biomarkers of response.


Assuntos
Transcriptoma , Vitamina D , Proteínas de Transporte , Colecalciferol , Suplementos Nutricionais , Humanos , Mucosa , Proteínas Serina-Treonina Quinases , Reto , Reprodutibilidade dos Testes
4.
Gut ; 69(1): 103-111, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31023832

RESUMO

OBJECTIVE: We assessed the effect of surgical resection of colorectal cancer (CRC) on perioperative plasma vitamin D (25OHD) and C-reactive protein (CRP) level. We investigated the relationship between circulating vitamin D level and CRC survival. DESIGN: We sequentially sampled 92 patients undergoing CRC resection, and measured plasma 25OHD and CRP. For survival analyses, we assayed 25OHD and CRP in two temporally distinct CRC patient cohorts (n=2006, n=2100) and investigated the association between survival outcome, circulating vitamin D and systemic inflammatory response. RESULTS: Serial sampling revealed a postoperative fall (mean 17.3 nmol/L; p=3.6e-9) in plasma 25OHD (nadir days 1-2). CRP peaked 3-5 days postoperatively (143.1 mg/L; p=1.4e-12), yet the postoperative fall in 25OHD was independent of CRP. In cohort analyses, 25OHD was lower in the 12 months following operation (mean=48.8 nmol/L) than preoperatively (54.8 nmol/L; p=1.2e-5) recovering after 24 months (52.2 nmol/L; p=0.002). Survival analysis in American Joint Committee on Cancer stages I-III demonstrated associations between 25OHD tertile and CRC mortality (HR=0.69; 95% CI 0.46 to 0.91) and all-cause mortality (HR=0.68; 95% CI 0.50 to 0.85), and was independent of CRP. We observed interaction effects between plasma 25OHD and rs11568820 genotype (functional VDR polymorphism) with a strong protective effect of higher 25OHD only in patients with GG genotype (HR=0.51; 95% CI 0.21 to 0.81). We developed an online tool for predicted survival (https://apps.igmm.ed.ac.uk/mortalityCalculator/) that incorporates 25OHD with clinically useful predictive performance (area under the curve 0.77). CONCLUSIONS: CRC surgery induces a fall in circulating 25OHD. Plasma 25OHD level is a prognostic biomarker with low 25OHD associated with poorer survival, particularly in those with rs11568820 GG genotype. A randomised trial of vitamin D supplementation after CRC surgery has compelling rationale.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias Colorretais/cirurgia , Vitamina D/análogos & derivados , Idoso , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Feminino , Seguimentos , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Prognóstico , Receptores de Calcitriol/genética , Análise de Sobrevida , Síndrome de Resposta Inflamatória Sistêmica/sangue , Vitamina D/sangue
5.
Colorectal Dis ; 20 Suppl 8: 3-117, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30508274

RESUMO

AIM: There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology. METHODS: Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines. RESULTS: All aspects of surgical care for IBD have been included along with 157 recommendations for management. CONCLUSION: These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.


Assuntos
Cirurgia Colorretal/normas , Gastroenterologia/normas , Doenças Inflamatórias Intestinais/cirurgia , Consenso , Humanos , Sociedades Médicas , Reino Unido
6.
Br J Cancer ; 116(8): 1092-1110, 2017 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-28301870

RESUMO

BACKGROUND: Vitamin D has been linked with improved cancer outcome. This systematic review and meta-analysis investigates the relationship between cancer outcomes and both vitamin D-related genetic variation and circulating 25-hydroxyvitamin D (25OHD) concentration. METHODS: A systematic review and meta-analysis of papers until November 2016 on PubMed, EMBASE and Web of Science pertaining to association between circulating vitamin D level, functionally relevant vitamin D receptor genetic variants and variants within vitamin D pathway genes and cancer survival or disease progression was performed. RESULTS: A total of 44 165 cases from 64 studies were included in meta-analyses. Higher 25OHD was associated with better overall survival (hazard ratio (HR=0.74, 95% CI: 0.66-0.82) and progression-free survival (HR=0.84, 95% CI: 0.77-0.91). The rs1544410 (BsmI) variant was associated with overall survival (HR=1.40, 95% CI: 1.05-1.75) and rs7975232 (ApaI) with progression-free survival (HR=1.29, 95% CI: 1.02-1.56). The rs2228570 (FokI) variant was associated with overall survival in lung cancer patients (HR=1.29, 95% CI: 1.0-1.57), with a suggestive association across all cancers (HR=1.26, 95% CI: 0.96-1.56). CONCLUSIONS: Higher 25OHD concentration is associated with better cancer outcome, and the observed association of functional variants in vitamin D pathway genes with outcome supports a causal link. This analysis provides powerful background rationale to instigate clinical trials to investigate the potential beneficial effect of vitamin D in the context of stratification by genotype.


Assuntos
Variação Genética/genética , Neoplasias/sangue , Neoplasias/genética , Receptores de Calcitriol/genética , Vitamina D/análogos & derivados , Predisposição Genética para Doença , Humanos , Prognóstico , Vitamina D/sangue
7.
Phys Rev Lett ; 116(17): 172501, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27176517

RESUMO

Precision measurements of superallowed Fermi ß-decay transitions, particularly for the lightest superallowed emitters ^{10}C and ^{14}O, set stringent limits on possible scalar current contributions to the weak interaction. In the present work, a discrepancy between recent measurements of the ^{10}C half-life is addressed through two high-precision half-life measurements, via γ-ray photopeak and ß counting, that yield consistent results for the ^{10}C half-life of T_{1/2}=19.2969±0.0074 s and T_{1/2}=19.3009±0.0017 s, respectively. The latter is the most precise superallowed ß-decay half-life measurement reported to date and the first to achieve a relative precision below 10^{-4}. A fit to the world superallowed ß-decay data including the ^{10}C half-life measurements reported here yields b_{F}=-0.0018±0.0021 (68% C.L.) for the Fierz interference term and C_{S}/C_{V}=+0.0009±0.0011 for the ratio of the weak scalar to vector couplings assuming left-handed neutrinos.

8.
Br J Dermatol ; 174(5): 1068-78, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26581342

RESUMO

BACKGROUND: Solar ultraviolet B (UVB) radiation is the major source of vitamin D (vitD) for humans. OBJECTIVES: To describe ambient UVB radiation at wavelengths that induce vitD synthesis (vitD-UVB) in Scotland, and to examine the relationship to serum 25-hydroxyvitamin D (25OHD). METHODS: We estimated the average vitD-UVB dose for each day of the year and for each postcode area in Scotland, using the Tropospheric Emission Monitoring Internet Service database. Cumulative and weighted vitD-UVB (CW-vitD-UVB) exposure at place of residence was calculated for each participant. Plasma 25OHD was assayed in 1964 healthy participants. RESULTS: Significant seasonal and geographical variation in vitD-UVB was observed. Ambient vitD-UVB exposure at place of residence was significantly associated with plasma 25OHD (P < 0·01). An average increase in 25OHD of 1 ng mL(-1) was observed for every 1000 mJ cm(-2) higher CW-vitD-UVB dose or for every 2·5 µg of daily supplement taken. Adequate 25OHD concentration (> 16 ng mL(-1)) was observed in the majority when CW-vitD-UVB dose was > 6000 mJ cm(-2), a level of ambient radiation achieved only in summer months in Scotland. When predicting vitD deficiency, dramatic improvement in the area under the curve was observed (from 0·55 to 0·70) after CW-vitD-UVB dose was added to the model, in addition to a range of other covariates. CONCLUSIONS: Ambient vitD-UVB can be a useful predictor of vitD status. Geotemporally mapped measurements of vitD-UVB can be used as a proxy for vitD status or as a covariate in epidemiological research, particularly if 25OHD is unavailable.


Assuntos
Raios Ultravioleta , Vitamina D/análogos & derivados , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Criança , Pré-Escolar , Suplementos Nutricionais , Relação Dose-Resposta à Radiação , Exposição Ambiental/análise , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Características de Residência , Estudos Retrospectivos , Escócia/epidemiologia , Estações do Ano , Vitamina D/administração & dosagem , Vitamina D/metabolismo , Deficiência de Vitamina D/sangue , Vitaminas/administração & dosagem , Adulto Jovem
10.
Colorectal Dis ; 17(4): 329-34, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25359603

RESUMO

AIM: Symptomatic diverticular disease (DD) may be increasing in incidence in western society particularly in younger age groups. This study aimed to describe hospital admission rates and management for DD in Scotland between 2000 and 2010. METHOD: Data were obtained from the Scottish Morbidity Records (SMR01). The study cohort included all patients with a hospital admission and a primary diagnosis of DD of the large intestine (ICD-10 primary code K57). RESULTS: Scottish NHS hospitals reported 90 990 admissions for DD (in 87 314 patients) from 2000 to 2010. The annual number of admissions increased by 55.2% from 6591 in 2000 to 10,228 in 2010, an average annual increase per year of 4.5%. Most of the increase attributable to DD was due to elective day cases (3618 in 2000; 6925 in 2010) a likely consequence of a greater proportion of the population accessing colonoscopy over that time period. There was an 11% increase in inpatient admissions (2973-3303), 60% of these patients being women. Admissions in younger age groups increased proportionally in the later years of the study, and there was an association between DD admissions and greater deprivation. Despite an increase in complicated DD from 22.9% in 2000 to 27.1% in 2010 and a 16.8% increase in emergency inpatient admissions, the rate of surgery fell during the period of study. CONCLUSION: This report supports findings of other population-based studies of western countries indicating that DD is an increasing burden on health service resources, particularly in younger age groups.


Assuntos
Doença Diverticular do Colo/epidemiologia , Hospitalização/estatística & dados numéricos , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Colectomia , Colonoscopia , Doença Diverticular do Colo/diagnóstico , Doença Diverticular do Colo/terapia , Feminino , Humanos , Incidência , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Escócia/epidemiologia , Distribuição por Sexo
11.
Clin Genet ; 84(3): 244-50, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23170986

RESUMO

The MSH2 c.388_389del mutation has occasionally been described in Lynch families worldwide. At the Portuguese Oncology Institute in Porto, Portugal, we have identified 16 seemingly unrelated families with this germline mutation. To evaluate if this alteration is a founder or a recurrent mutation we performed haplotype analysis in the 16 Portuguese index cases and 55 relatives, as well as in four index cases and 13 relatives reported from Germany, Scotland, England, and Argentina. In the Portuguese families we observed a shared haplotype of approximately 10 Mb and all were originated from the north of Portugal. These results suggest that this alteration is a founder mutation in Portugal with a relatively recent origin. In the reported families outside Portugal with this mutation different haplotype backgrounds were observed, supporting the hypothesis that it occurred de novo on multiple occasions. We also conclude that the high proportion of families with the MSH2 c.388_389del mutation indicates that screening for this alteration as a first step may be cost-effective in the genetic testing of Lynch syndrome suspects of Portuguese ancestry, especially those originating from the north of Portugal.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Efeito Fundador , Proteína 2 Homóloga a MutS/genética , Deleção de Sequência , Argentina , Sequência de Bases , Inglaterra , Mutação em Linhagem Germinativa , Alemanha , Haplótipos , Humanos , Repetições de Microssatélites , Motivos de Nucleotídeos , Polimorfismo de Nucleotídeo Único , Portugal
12.
Gut ; 61(2): 248-54, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21708826

RESUMO

BACKGROUND AND AIMS: Shorter telomeres have been associated with increased risk of malignancy, including colorectal cancer (CRC). Telomere length is heritable and may be an intermediate phenotype linked to genetic susceptibility to CRC. METHODS: In a large sample, the study investigated whether candidate single nucleotide polymorphisms (SNP) in 'telomere biology' genes were associated with telomere length in leucocytes. SNP associated with an increased risk of CRC were searched for separately. RESULTS: Carriers of the common allele at SNP rs10936599, near the telomerase RNA component (TERC) locus, had significantly longer telomeres. It was independently found that the same rs10936599 allele was associated with increased risk of both CRC and colorectal adenomas. Neither telomere length nor CRC risk was associated with variation near telomerase reverse transcriptase or other telomere biology genes. In silico analysis showed that SNP rs2293607 was strongly correlated with rs10936599, mapped within TERC transcripts, had a predicted effect on messenger RNA folding and lay at a reported transcription factor binding site. TERC mRNA were expressed, differing only at the alleles of rs2293607, in CRC cell line HCT116. The long-telomere/CRC-risk allele was associated with higher levels of TERC mRNA and the formation of longer telomeres. CONCLUSIONS: Common genetic variation at TERC is associated with both longer telomeres and an increased risk of CRC, a potential mechanism being reduced levels of cell senescence or death. This finding is somewhat paradoxical, given retrospective studies reporting that CRC cases have shorter telomeres than controls. One possibility is that that association actually results from poorer survival in patients with longer telomeres.


Assuntos
Neoplasias Colorretais/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , RNA/genética , Telomerase/genética , Telômero/química , Adenoma/genética , Idoso , Carcinoma/genética , Estudos de Casos e Controles , Feminino , Técnicas de Genotipagem , Células HCT116 , Humanos , Leucócitos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Telômero/genética
13.
PLoS One ; 18(11): e0286493, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37930977

RESUMO

BACKGROUND: Nearly 50 million people worldwide have dementia and the increasing numbers requiring end-of-life and palliative care, has led to national efforts to define standards of care for this patient group. Little research, however, has been done to date about the experience of hospice care for people with dementia accessing these services. This study explores the views of hospice dementia care for bereaved carers of people with dementia and hospice clinicians. METHODS: We used purposive sampling for participant recruitment. Semi-structured qualitative interviews were conducted with bereaved carers and hospice clinical staff. Interviews were audio recorded and the transcriptions were analysed through thematic analysis. A total of 12 participants were interviewed from one service in the Northwest region in the UK. All were female and white British. RESULTS: Participants described their experience of hospice dementia care in three main themes: Pre-access to service, roles and responsibility within hospice care, ease and difficulty of last period of end-of-life care. CONCLUSION: Rapid response teams delivering hospice home care could represent a better option to inpatient care and may be preferred by patients. This type of service, however, may require joined-up care with other community services, and this type of care needs to be considered and planned. Future studies should evaluate this type of community care.


Assuntos
Demência , Cuidados Paliativos na Terminalidade da Vida , Hospitais para Doentes Terminais , Humanos , Feminino , Masculino , Cuidadores , Cuidados Paliativos , Pesquisa Qualitativa
14.
Front Nutr ; 10: 1106431, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063332

RESUMO

Background: Vitamin D supplementation improves colorectal cancer (CRC) survival outcomes in randomized trials. The aim of this study was to test the feasibility, safety and efficacy of vitamin D supplementation in the pre- and perioperative period in patients undergoing CRC surgery. Methods: Patients were given 3200IU oral cholecalciferol (D3) per day perioperatively. Serial serum 25-hydroxyvitamin (25OHD) was measured by liquid chromatography tandem mass spectrometry and compared to untreated CRC controls. 25OHD and C-reactive protein (CRP) levels were compared using adjusted generalized linear mixed-effects models. Results: A total of 122 patients underwent serial perioperative sampling, including 41 patients given high-dose perioperative supplementation. Supplementation was well-tolerated with no adverse or serious adverse events related to supplementation reported. Pre-operative supplementation increased 25OHD levels on the day of surgery (103.9 vs. 42.5 nmol/l, P = 8.2E-12). Supplementation increased 25OHD levels at all post-operative timepoints (P < 0.001) and attenuated the post-operative drop in 25OHD (46 vs. 24% drop, P = 3.0E-4). Rate of vitamin D peri-operative insufficiency was significantly less in those on supplementation (e.g., day 3-5, 14 vs. 84%, P = 1.41E-08), with multivariate modeling across all timepoints indicating a ∼59 nmol/l higher 25OHD compared to control patients (P = 3.7E-21). Post-operative CRP was lower in patients taking supplementation (e.g., day 3-5 timepoint; 129 vs. 81 mg/l, P = 0.04). Conclusion: High dose pre-operative vitamin D supplementation is associated with higher perioperative 25OHD levels, lower rates of vitamin D insufficiency and reduced early post-operative CRP. Alongside published evidence for a beneficial effect of vitamin D on CRC survival outcomes, these novel findings provide strong rationale for early initiation of vitamin D supplementation after a diagnosis of CRC.

15.
Genet Epidemiol ; 35(5): 423-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21254221

RESUMO

Using genome-wide association studies to identify genetic variants contributing to disease has been highly successful with many novel genetic predispositions identified and biological pathways revealed. Several pitfalls for spurious association or non-replication have been highlighted: from population structure, automated genotype scoring for cases and controls, to age-varying association. We describe an important yet unreported source of bias in case-control studies due to variations in chip technology between different commercial array releases. As cases are commonly genotyped with newer arrays and freely available control resources are frequently used for comparison, there exists an important potential for false associations which are robust to standard quality control and replication design.


Assuntos
Estudo de Associação Genômica Ampla/estatística & dados numéricos , Genótipo , Polimorfismo de Nucleotídeo Único , Viés , Estudos de Casos e Controles , Análise por Conglomerados , Humanos , Análise de Sequência com Séries de Oligonucleotídeos/estatística & dados numéricos
17.
Br J Cancer ; 107(6): 1001-8, 2012 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-22878375

RESUMO

BACKGROUND: Polymorphic variation at the 5p15.33 (TERT-CLPTM1L) locus is associated with the risk of many cancers but a relationship with colorectal cancer (CRC) risk has yet to be defined. METHODS: We used data from six genome-wide association studies (GWAS) of CRC, linkage disequilibrium mapping and imputation, to examine the relationship between 73 single-nucleotide polymorphisms at 5p15.33 and CRC risk in detail. RESULTS: rs2736100, which localises to intron 2 of TERT, provided the strongest evidence of an association with CRC (P=2.28 × 10⁻4). The association was also shown in an independent series of 10 047 CRC cases and 6918 controls (P=0.02). A meta-analysis of all seven studies (totalling 16 039 cases, 16 430 controls) provided increased evidence of association (P=2.49 × 10⁻5; per allele odds ratio=1.07). The association of rs2736100 on CRC risk was shown to be independent of 15 low-penetrance variants previously identified. CONCLUSION: The rs2736100 association demonstrates an influence of variation at 5p15.33 on CRC risk and further evidence that the 5p15.33 (TERT-CLPTM1L) locus has pleiotropic effects (reflecting generic or lineage-specific effects) on cancer risk.


Assuntos
Cromossomos Humanos Par 5 , Neoplasias Colorretais/genética , Desequilíbrio de Ligação , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Telomerase/genética , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Medição de Risco , Fatores de Risco
18.
Phys Rev Lett ; 107(2): 025004, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21797615

RESUMO

The extent of where magnetic reconnection (MR), the dominant process responsible for energy and plasma transport into the magnetosphere, operates across Earth's dayside magnetopause has previously been only indirectly shown by observations. We report the first direct evidence of X-line structure resulting from the operation of MR at each of two widely separated locations along the tilted, subsolar line of maximum current on Earth's magnetopause, confirming the operation of MR at two or more sites across the extended region where MR is expected to occur. The evidence results from in-situ observations of the associated ion and electron plasma distributions, present within each magnetic X-line structure, taken by two spacecraft passing through the active MR regions simultaneously.

19.
Nat Med ; 1(4): 348-52, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7585065

RESUMO

Replication errors (RER) associated with genetic instability have been found in cancers of several different types and particularly in the tumours of patients with hereditary non-polyposis colorectal cancer (HNPCC). We have here determined the prevalence of such instability in relation to age among patients without HNPCC. Colorectal cancers (CRCs) in the majority of patients 35 years of age or younger exhibited instability (58% of 31 patients), whereas CRCs from patients older than 35 uncommonly did (12% of 158, p < 0.0001). Twelve of the patients under 35 with instability were evaluated for alterations of mismatch repair genes, and five were found to harbour germline mutations. These data suggest that the mechanisms underlying tumour development in young CRC patients differ from those in most older patients, regardless of HNPCC status. The results have important implications for genetic testing and management of young CRC patients and their families.


Assuntos
Neoplasias Colorretais/genética , Replicação do DNA/genética , DNA Satélite/genética , Proteínas Fúngicas , Adulto , Idoso , Envelhecimento/genética , Sequência de Bases , Primers do DNA/química , DNA de Neoplasias/análise , Proteínas de Ligação a DNA/genética , Mutação em Linhagem Germinativa , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteína 2 Homóloga a MutS , Prevalência
20.
Nat Med ; 2(2): 169-74, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8574961

RESUMO

Hereditary non-polyposis colorectal cancer (HNPCC) is an autosomal dominant disorder characterized by the early onset of colorectal cancer and linked to germline defects in at least four mismatch repair genes. Although much has been learned about the molecular pathogenesis of this disease, questions related to effective presymptomatic diagnosis are largely unanswered because of its genetic complexity. In this study, we evaluated tumors from 74 HNPCC kindreds for genomic instability characteristic of a mismatch repair deficiency and found such instability in 92% of the kindreds. The entire coding regions of the five known human mismatch repair genes were evaluated in 48 kindreds with instability, and mutations were identified in 70%. This study demonstrates that a combination of techniques can be used to genetically diagnose tumor susceptibility in the majority of HNPCC kindreds and lays the foundation for genetic testing of this relatively common disease.


Assuntos
Biomarcadores Tumorais , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA , Genes Neoplásicos , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Sequência de Bases , Família , Genes Dominantes , Humanos , Dados de Sequência Molecular , Proteína 3 Homóloga a MutS , Mutação , Proteínas/genética
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