743 research outputs found
Long-term prognosis of early-onset breast cancer in a population-based cohort with a known BRCA1/2 mutation status.
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This article is open access.All women in the South Sweden Health Care Region with breast cancer diagnosed aged less than 41 during the period between 1990 and 1995 were contacted in 1996 and offered germline mutation analysis of the BRCA1 and BRCA2 genes. Mutation carriers (n = 20) were compared with noncarriers (n = 201) for overall survival (OS) and risk of contralateral breast cancer (CBC). Mutation carriers were younger at diagnosis and more likely to have ER-negative, PgR-negative and grade III tumors. Median follow-up was 19 years. The 5-, 10-, 15-, and 20-year OS were 60, 45, 39, and 39 % for mutation carriers and 82, 70, 59, and 53 % for noncarriers, respectively (5-year log-rank P = 0.013; 10-year P = 0.008; 15-year P = 0.020; and 20-year P = 0.046). In univariable analysis, there was a trend for an inferior OS for mutation carriers (HR 1.8; 95 % CI 1.0-3.3). When stratified for use of (neo)adjuvant chemotherapy, an inferior OS was significant only for the subgroup of patients who did not receive chemotherapy (HR 3.0; 95 % CI 1.2-7.7). In multivarible analysis, BRCA1/2 mutation status was a significant predictor of OS when adjusting for tumor stage, age, and use of chemotherapy, but not when ER status was also included in the model. The 15-year cumulative risk of CBC was 53 % for mutation carriers and 10 % for noncarriers (HR 5.9; 95 % CI 1.9-18.6); among the noncarriers the risks were 5, 22, and 30 % for patients without close relatives having breast cancer, with second-degree relatives having breast cancer, and with firstdegree relatives with breast cancer, respectively. In conclusion, the poor prognosis of young BRCA1/2 mutation carriers with breast cancer is mainly explained by the prevalent occurrence of negative prognostic factors rather than mutation status per se, and can to at least some extent be abrogated by the use of chemotherapy.Skane County Counsil's Research and Development Foundation
The Swedish Breast Cancer Association (BRO)
BioCAR
The distinct features of microbial 'dysbiosis' of Crohn's disease do not occur to the same extent in their unaffected, genetically linked kindred
Background/Aims:
Studying the gut microbiota in unaffected relatives of people with Crohn’s disease (CD) may advance our understanding of the role of bacteria in disease aetiology.
Methods:
Faecal microbiota composition (16S rRNA gene sequencing), genetic functional capacity (shotgun metagenomics) and faecal short chain fatty acids (SCFA) were compared in unaffected adult relatives of CD children (CDR, n = 17) and adult healthy controls, unrelated to CD patients (HUC, n = 14). The microbiota characteristics of 19 CD children were used as a benchmark of CD ‘dysbiosis’.
Results:
The CDR microbiota was less diverse (p = 0.044) than that of the HUC group. Local contribution of β-diversity analysis showed no difference in community structure between the CDR and HUC groups. Twenty one of 1,243 (1.8%) operational taxonomic units discriminated CDR from HUC. The metagenomic functional capacity (p = 0.207) and SCFA concentration or pattern were similar between CDR and HUC (p>0.05 for all SCFA). None of the KEGG metabolic pathways were different between these two groups. Both of these groups (HUC and CDR) had a higher microbiota α-diversity (CDR, p = 0.026 and HUC, p<0.001) with a community structure (β-diversity) distinct from that of children with CD.
Conclusions:
While some alterations were observed, a distinct microbial ‘dysbiosis’, characteristic of CD patients, was not observed in their unaffected, genetically linked kindred
High risk of in-breast tumor recurrence after BRCA1/2-associated breast cancer
The purpose of the study was to compare breast-conserving therapy (BCT) and mastectomy (M) in BRCA1/2 mutation carriers. Women with invasive breast cancer and a pathogenic mutation in BRCA1 or BRCA2 were included in the study (n = 162). Patients treated with BCT (n = 45) were compared with patients treated with M (n = 118). Endpoints were local recurrence as first recurrence (LR), overall survival (OS), breast cancer death, and distant recurrence. Cumulative incidence was calculated in the presence of competing risks. For calculation of hazard ratios and for multivariable analysis, cause-specific Cox proportional hazards regression was used. Compared to M, BCT was associated with an increased risk of LR in univariable analysis (HR 4.0; 95 % CI 1.6-9.8) and in multivariable analysis adjusting for tumor stage, age, and use of adjuvant chemotherapy (HR 2.9; CI 1.1-7.8). Following M, all local recurrences were seen in the first 5 years after breast cancer diagnosis. Following BCT, the rate of LR continued to be high also after the first 5 years. The cumulative incidence of LR in the BCT group was 15, 25, and 32 % after 5, 10, and 15 years, respectively. There were no significant differences between BCT and M for OS, breast cancer death, or distant recurrence. BRCA1/2 mutation carriers treated with BCT have a high risk of LR, many of which are new primary breast cancers. This must be thoroughly discussed with the patient and is an example of how rapid treatment-focused genetic testing could influence choice of treatment
High risk of in-breast tumor recurrence after BRCA1/2-associated breast cancer.
To access publisher's full text version of this article click on the hyperlink at the bottom of the pageThe purpose of the study was to compare breast-conserving therapy (BCT) and mastectomy (M) in BRCA1/2 mutation carriers. Women with invasive breast cancer and a pathogenic mutation in BRCA1 or BRCA2 were included in the study (n = 162). Patients treated with BCT (n = 45) were compared with patients treated with M (n = 118). Endpoints were local recurrence as first recurrence (LR), overall survival (OS), breast cancer death, and distant recurrence. Cumulative incidence was calculated in the presence of competing risks. For calculation of hazard ratios and for multivariable analysis, cause-specific Cox proportional hazards regression was used. Compared to M, BCT was associated with an increased risk of LR in univariable analysis (HR 4.0; 95 % CI 1.6-9.8) and in multivariable analysis adjusting for tumor stage, age, and use of adjuvant chemotherapy (HR 2.9; CI 1.1-7.8). Following M, all local recurrences were seen in the first 5 years after breast cancer diagnosis. Following BCT, the rate of LR continued to be high also after the first 5 years. The cumulative incidence of LR in the BCT group was 15, 25, and 32 % after 5, 10, and 15 years, respectively. There were no significant differences between BCT and M for OS, breast cancer death, or distant recurrence. BRCA1/2 mutation carriers treated with BCT have a high risk of LR, many of which are new primary breast cancers. This must be thoroughly discussed with the patient and is an example of how rapid treatment-focused genetic testing could influence choice of treatment.Regional Ethical Review Board in Lund
Skane County Counsil's Research and Development Foundation
Swedish Breast Cancer Association (BRO)
Swedish Cancer Society
BioCAR
Reagent and laboratory contamination can critically impact sequence-based microbiome analyses.
BACKGROUND: The study of microbial communities has been revolutionised in recent years by the widespread adoption of culture independent analytical techniques such as 16S rRNA gene sequencing and metagenomics. One potential confounder of these sequence-based approaches is the presence of contamination in DNA extraction kits and other laboratory reagents. RESULTS: In this study we demonstrate that contaminating DNA is ubiquitous in commonly used DNA extraction kits and other laboratory reagents, varies greatly in composition between different kits and kit batches, and that this contamination critically impacts results obtained from samples containing a low microbial biomass. Contamination impacts both PCR-based 16S rRNA gene surveys and shotgun metagenomics. We provide an extensive list of potential contaminating genera, and guidelines on how to mitigate the effects of contamination. CONCLUSIONS: These results suggest that caution should be advised when applying sequence-based techniques to the study of microbiota present in low biomass environments. Concurrent sequencing of negative control samples is strongly advised
Extreme genetic fragility of the HIV-1 capsid
Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies
Microevolution and maternal effects on tadpole Rana temporaria growth and development rate
Mobile real-time surveillance of Zika virus in Brazil
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Previous issue date: 2016-09-29University of Oxford. Department of Zoology. South Parks Road. Oxford, UK.University of Sao Paulo. Department of Infectious Diseases and Institute of Tropical Medicine. São Paulo, BrasilMinistry of Health. Evandro Chagas Institute. Center for Technological Innovation. Ananindeua, PA, Brasil / University of Texas Medical Branch. Department of Pathology. Galveston, USAFundação Gonçalo Moniz, Centro de Pesquisas Gonçalo Moniz. Salvador, BA, BrasilUniversity of Birmingham. Institute of Microbiology and Infection. Birmingham, UK.The World Health Organization has declared Zika virus an international public health emergency. Knowledge of Zika virus genomic epidemiology is currently limited due to challenges in obtaining and processing samples for sequencing. The ZiBRA project is a United Kingdom-Brazil collaboration that aims to improve this situation using new sequencing technologies
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