| 21. |
- Osorio, Ana, et al.
(författare)
-
DNA Glycosylases Involved in Base Excision Repair May Be Associated with Cancer Risk in BRCA1 and BRCA2 Mutation Carriers.
- 2014
-
Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 10:4
-
Tidskriftsartikel (refereegranskat)abstract
- Single Nucleotide Polymorphisms (SNPs) in genes involved in the DNA Base Excision Repair (BER) pathway could be associated with cancer risk in carriers of mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of the components of the BER pathway, PARP1 (poly ADP ribose polymerase), and both BRCA1 and BRCA2. In the present study, we have performed a comprehensive analysis of 18 genes involved in BER using a tagging SNP approach in a large series of BRCA1 and BRCA2 mutation carriers. 144 SNPs were analyzed in a two stage study involving 23,463 carriers from the CIMBA consortium (the Consortium of Investigators of Modifiers of BRCA1 and BRCA2). Eleven SNPs showed evidence of association with breast and/or ovarian cancer at p<0.05 in the combined analysis. Four of the five genes for which strongest evidence of association was observed were DNA glycosylases. The strongest evidence was for rs1466785 in the NEIL2 (endonuclease VIII-like 2) gene (HR: 1.09, 95% CI (1.03-1.16), p = 2.7×10-3) for association with breast cancer risk in BRCA2 mutation carriers, and rs2304277 in the OGG1 (8-guanine DNA glycosylase) gene, with ovarian cancer risk in BRCA1 mutation carriers (HR: 1.12 95%CI: 1.03-1.21, p = 4.8×10-3). DNA glycosylases involved in the first steps of the BER pathway may be associated with cancer risk in BRCA1/2 mutation carriers and should be more comprehensively studied.
|
|
| 22. |
- Quétel, C. R., et al.
(författare)
-
Methylmercury in tuna: demonstrating measurement capabilities and evaluating comparability of results worldwide from the CCQM P-39 comparison
- 2005
-
Ingår i: Journal of Analytical Atomic Spectrometry. - : Royal Society of Chemistry (RSC). - 0267-9477 .- 1364-5544. ; 20, s. 1058-66
-
Tidskriftsartikel (refereegranskat)abstract
- Six metrology institutes (NMIs) representing at the Comité International des Poids et Mesures (CIPM) 4 Member States of the Metre Convention and 2 international organisations, and 8 expert laboratories selected outside CIPM have compared their capabilities to quantitatively measure methylmercury (MeHg) in a prepared tuna material containing approximately 4.3 mg kg–1 Hg. This comparison was the object of the CIPM–Comité Consultatif pour la Quantité de Matière (CCQM) Pilot Study 39, organised by the Institute for Reference Materials and Measurements (IRMM), from the European Commission—Joint Research Centre. Beside the test material itself, a bottle of the BCR-464 tuna Certified Reference Material (CRM) and an ampoule of IRMM-670, a 202Hg isotope enriched MeHg candidate isotopic CRM, were distributed to all participants, who were free to apply the measurement strategy of their choice. Four, including 1 NMI, relied on external calibration or the method of standard additions, whereas the other 10 implemented an isotope dilution mass spectrometry (IDMS) approach and chose to use the IRMM-670 for their measurements. Alkaline digestion at room temperature (with manual shaking) or high temperature (under sonication, oven or hot plate conditions) was employed by most participants, with hydrochloric acid leaching the second most popular choice. Alkylation (4 phenylations, 4 ethylations and 3 propylations) in the aqueous phase was preferred by a large majority over butylation by the Grignard reaction. All participants were requested to estimate the uncertainty associated with their results and 9 out of 14 stated relative combined uncertainties below 6%(k= 2). Despite this apparent consensus, the perception of which factor caused the largest contribution to this estimation differed among participants because of the differences in the analytical methodologies deployed but also because of wide differences of the concepts of uncertainty estimation. The mixture mode(MM) median, calculated also from the measurement uncertainties stated by the participants, was 1.967 ± 0.204 × 10–5 mol kg–1(95% confidence). Twelve of the results were re-grouped within a range of less than 0.3 × 10–5 mol kg–1(MM median = 1.967 ± 0.162 × 10–5 mol kg–1, 95% confidence): they nearly all (1 exception) overlapped with each other within k= 2 stated uncertainties. For the other 2 results the uncertainty seemed to have been particularly underestimated as they lay, respectively, at more than 20% above and less than –40% below the overall average. The relative standard deviation of the results of 9 laboratories out of the 10 that applied IDMS was about 2.6%. It can be assumed from the degree of equivalence shown by 12 out of 14 study participants that, at present, laboratories worldwide are potentially able to supply accurate results for MeHg in fish-type matrices (containing about 2 × 10–5 mol kg–1) within ±10% uncertainty. This encouraging outcome permitted scheduling of a follow-up CCQM-K43 key comparison for a lower MeHg content level in salmon tissues.
|
|
| 23. |
|
|
| 24. |
- Sitkauskiene, Brigita, et al.
(författare)
-
Screening for alpha1-antitrypsin deficiency in Lithuanian patients with COPD
- 2008
-
Ingår i: Respiratory Medicine. - : Elsevier BV. - 1532-3064 .- 0954-6111. ; 102:11, s. 1654-1658
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Alphal-antitrypsin (AAT) deficiency is an under-diagnosed condition in patients with chronic obstructive pulmonary disease (COPD). The objective of the present screening was to estimate the AAT gene frequency and prevalence and to identify AAT deficiency cases in a large cohort of Lithuanian patients with COPD. Methods: A nationwide program of AAT deficiency was conducted in 1167 COPD patients, defined according to the GOLD criteria. Patients were collected from outpatient clinics in five different Lithuanian regions (Kaunas, Vilnius, Siauliai, Klaipeda and Alytus). AAT serum concentrations were measured by nephelometry; PI-phenotypes characterized by isoelectric-focusing. Results: Mean age and FEV1 were 62.0 (10.3) and 54.7% (10.9), respectively. Ninety-one AAT deficiency genotypes (40 MZ, 39 MS, 1 SS, 3 SZ and 8 ZZ) were identified. Catculated PI*S and PI*Z frequencies, expressed in per 1000, were 18.8 (95% CI: 13.9-25) and 25.3 (95% CI: 19.4-32.7), respectively. The calculated AAT gene prevalence (Hardy-Weinberg principle) was: 1/1.09 for MM, 1/28 for MS, 1/2814 for SS, 1/20 for MZ, 1/1049 for SZ and 1/1565 for ZZ. Calculated Odds ratio (OR) for PI*Z in COPD vs. Lithuanian healthy people was of 1.87 (P = 0.004). Conclusion: The OR for each genotypic class demonstrated a significant increase of MZ, SZ and ZZ genotypes in COPD patients. The results of the present study, with a significant number of ZZ individuals detected, support the general concept of targeted screening for AAT deficiency in countries like Lithuania, with a large population of COPD patients and tow awareness among care-givers about this genetic condition. (C) 2008 Elsevier Ltd. All rights reserved.
|
|
