373 research outputs found
Chromosomal aberration frequency in lymphocytes predicts the risk of cancer: results from a pooled cohort study of 22 358 subjects in 11 countries
Mechanistic evidence linking chromosomal aberration (CA) to early stages of cancer has been recently supported by the results of epidemiological studies that associated CA frequency in peripheral lymphocytes of healthy individuals to future cancer incidence. To overcome the limitations of single studies and to evaluate the strength of this association, a pooled analysis was carried out. The pooled database included 11 national cohorts and a total of 22 358 cancer-free individuals who underwent genetic screening with CA for biomonitoring purposes during 1965–2002 and were followed up for cancer incidence and/or mortality for an average of 10.1 years; 368 cancer deaths and 675 incident cancer cases were observed. Subjects were classified within each laboratory according to tertiles of CA frequency. The relative risk (RR) of cancer was increased for subjects in the medium [RR = 1.31, 95% confidence interval (CI) = 1.07–1.60] and in the high (RR = 1.41; 95% CI = 1.16–1.72) tertiles when compared with the low tertile. This increase was mostly driven by chromosome-type aberrations. The presence of ring chromosomes increased the RR to 2.22 (95% CI = 1.34–3.68). The strongest association was found for stomach cancer [RRmedium = 1.17 (95% CI = 0.37–3.70), RRhigh = 3.13 (95% CI = 1.17–8.39)]. Exposure to carcinogens did not modify the effect of CA levels on overall cancer risk. These results reinforce the evidence of a link between CA frequency and cancer risk and provide novel information on the role of aberration subclass and cancer type
Mumificaçao fetal em suínos associada à toxoplasmose.
bitstream/item/58346/1/CUsersPiazzonDocuments271.pd
Bayes and Big Data: The Consensus Monte Carlo Algorithm
A useful definition of ‘big data’ is data that is too big to process comfortably on a single machine, either because of processor, memory, or disk bottlenecks. Graphics processing units can alleviate the processor bottleneck, but memory or disk bottlenecks can only be eliminated by splitting data across multiple machines. Communication between large numbers of machines is expensive (regardless of the amount of data being communicated), so there is a need for algorithms that perform distributed approximate Bayesian analyses with minimal communication. Consensus Monte Carlo operates by running a separate Monte Carlo algorithm on each machine, and then averaging individual Monte Carlo draws across machines. Depending on the model, the resulting draws can be nearly indistinguishable from the draws that would have been obtained by running a single-machine algorithm for a very long time. Examples of consensus Monte Carlo are shown for simple models where single-machine solutions are available, for large single-layer hierarchical models, and for Bayesian additive regression trees (BART)
Genetic susceptibility to malignant pleural mesothelioma and other asbestos-associated diseases.
Exposure to asbestos fibers is a major risk factor for malignant pleuralmesothelioma (MPM), lung cancer,
and other non-neoplastic conditions, such as asbestosis and pleural plaques. However, in the last decade
many studies have shown that polymorphism in the genes involved in xenobiotic and oxidative
metabolism or in DNA repair processes may play an important role in the etiology and pathogenesis of
these diseases. To evaluate the association between diseases linked to asbestos and genetic variability we
performed a review of studies on this topic included in the PubMed database. One hundred fifty-nine
citations were retrieved; 24 of them met the inclusion criteria and were evaluated in the review. The most
commonly studied GSTM1 polymorphism showed for all asbestos-linked diseases an increased risk in
association with the null genotype, possibly linked to its role in the conjugation of reactive oxygen
species. Studies focused on GSTT1 null and SOD2 Ala16Val polymorphisms gave conflicting results, while
promising results came from studies on a1-antitrypsin in asbestosis and MPO in lung cancer. Among
genetic polymorphisms associated to the risk of MPM, the GSTM1 null genotype and two variant alleles of
XRCC1 and XRCC3 showed increased risks in a subset of studies. Results for the NAT2 acetylator status,
SOD2 polymorphism and EPHX activity were conflicting. Major limitations in the study design, including
the small size of study groups, affected the reliability of these studies. Technical improvements such as
the use of high-throughput techniques will help to identify molecular pathways regulated by candidate
genes
Emissions generated by sugarcane burning promote genotoxicity in rural workers: a case study in Barretos, Brazil
Background: To determine the possible genotoxic effect of exposure to the smoke generated by biomass burning on workers involved in manual sugar cane harvesting.
Methods: The frequency of micronuclei in exfoliated buccal cells and peripheral blood lymphocytes was determined in sugarcane workers in the Barretos region of Brazil, during the harvest season and compared to a control population, comprised of administrative employees of Barretos Cancer Hospital.
Results: The frequency of micronuclei was higher in the sugar cane workers. The mean frequency in blood lymphocytes (micronuclei/1000 cells) in the test group was 8.22 versus 1.27 in the control group. The same effect was observed when exfoliated buccal cells were considered (22.75 and 9.70 micronuclei/1000 cells for sugar cane workers and controls, respectively).
Conclusion: Exposure to emissions produced by the burning of sugar cane during harvesting induces genomic instability in workers, indicating the necessity of adopting more advanced techniques of harvesting sugar cane to preserve human health.We thank the Researcher Support Center of Barretos Cancer Hospital, especially the statistician Zanardo C. for assisting in the statistical analysis. We thank Oliveira R. for technical support, and we acknowledge financial support from FAPESP Proc. 2010/10192-6
Association between Frequency of Chromosomal Aberrations and Cancer Risk Is Not Influenced by Genetic Polymorphisms in GSTM1 and GSTT1
To evaluate the role of polymorphisms in glutathione S-transferase M1 (GSTM1) and theta 1 (GSTT1) as effect modifiers of the association between CA and cancer risk. A case-control study was performed pooling data from cytogenetic studies carried out in 1974-1995 in three laboratories in Italy, Norway, and Denmark. The subjects were classified as low, medium, and high by tertile of CA frequency. The data were analysed by setting up a Bayesian model which included prior information about cancer risk by CA frequency
The Influence of Thermal Comfort on the Quality of Life of Nursing Home Residents
Thermal comfort (TC) parameters were measured in 130 rooms from nursing homes (NH), following ISO 7730:2005 in order to evaluate the influence of winter season TC indices on quality of life (QoL) in older individuals. Mean radiant temperature (mrT), predicted mean vote (PMV) and predicted percent of dissatisfied people (PPD) indices, and the respective measurement uncertainties were calculated using Monte Carlo Method. The WHOQOL-BREF questionnaire was conducted from September 2012 to April 2013, during the winter season TC sampling campaign. Winter PMV and PPD indices showed significant differences between seasons in median values for comfort. There were also significant differences between seasons for air temperature, air velocity, mrT, and relative humidity. The winter PMV index displayed a “slightly cool” [≤−1] to “cool” [≤−2] in thermal sensation scale [−3 to 3]. PPD index reflected this discomfort as evidenced by a high rate of predicted dissatisfied occupants (64%). The influence of winter season TC on older individual QoL results demonstrated that values of PMV above −0.7 had higher mean score of QoL (coefficient estimate: 11.13 units) compared with values of PMV below −0.7. These findings are of relevance to public health and may be useful for understanding NH indoor environment variables thus implementing preventive policies in terms of standards and guidelines for these susceptible populations.This work was supported by GERIA Project (www.geria.webnode.com): PTDC/SAU-SAP/116563/2010 and a PhD Grant (SFRH/BD/72399/2010) from Foundation for Science and Technology (Fundação para a Ciência e Tecnologia - FCT) through Operational Competitiveness Programme (COMPETE) as part of the National Strategic Reference Framework. SB work was supported by a grant funded by AIRC (Associazione Italiana per la Ricerca sul Cancro)
Acceptance and potential impact of the ewall platform for health monitoring and promotion in persons with a chronic disease or age-related impairment
Pervasive health technologies can increase the effectiveness of personal health monitoring and training, but more user studies are necessary to understand the interest for these technologies, and how they should be designed and implemented. In the present study, we evaluated eWALL, a user-centered pervasive health technology consisting of a platform that monitors users’ physical and cognitive behavior, providing feedback and motivation via an easy-to-use, touch-based user interface. The eWALL was placed for one month in the home of 48 subjects with a chronic condition (chronic obstructive pulmonary disease—COPD or mild cognitive impairment—MCI) or with an age-related impairment. User acceptance, platform use, and potential clinical effects were evaluated using surveys, data logs, and clinical scales. Although some features of the platform need to be improved before reaching technical maturity and making a difference in patients’ lives, the real-life evaluation of eWALL has shown how some features may influence patients’ intention to use this promising technology. Furthermore, this study made it clear how the free use of different health apps is modulated by the real needs of the patient and by their usefulness in the context of the patient’s clinical status
Wheat Variety Response to Seeding Rate in Kansas During the 2015–2016 and 2016– 2017 Growing Seasons
Plant density is among the major factors determining a crop’s ability to capture resources such as water, nutrients, and solar radiation; therefore, different wheat varieties might require different seeding densities to maximize yield. The objective of this project was to better understand the response of different wheat varieties to seeding rate. Two field experiments were conducted during 2015–2016 and repeated during 2016–2017, evaluating seven wheat varieties subjected to five different seeding rates (0.6, 0.95, 1.3, 1.65, and 2.0 million seeds/a). Crop was managed for a 70 bu/a yield goal and pests were controlled using commercially available pesticides. Final stand and grain yield were measured, and all statistical analyses were performed for relating emerged plants per acre to grain yield. At each individual environment and across varieties, grain yield usually was maximized at approximately 0.9 million emerged plants per acre. There were significant differences among varieties in grain yield, with Joe and Tatanka usually outperforming the remaining tested varieties. Across environments, grain yield usually was maximized at populations between 0.6 and 0.7 million plants per acre for less responsive varieties (1863, Everest, and Tatanka), at approximately 0.9 million plants per acre for average responsive varieties (Joe, Bob Dole, KanMark, and Zenda), and more than 1.05 million emerged plants per acre for more responsive varieties (Larry and AG Icon). These preliminary data suggests that there is the potential to manage each wheat variety according to its individual tillering potential; however, more data are needed to make definite conclusions about each variety’s optimum seeding rate. Thus, this experiment is currently being conducted at five sites during the 2017–18 growing season
Human amniotic mesenchymal stromal cells support the ex vivo expansion of cord blood hematopoietic stem cells
Currently over 30 000 allogeneic hematopoietic stem cell (HSC) transplantations have been performed for the treatment of hematological and nonhematological diseases using HSC from umbilical cord blood (CB). However, the wide utilization of CB as a source of HSC is limited by the low number of cells recovered. One strategy to expand ex vivo CB-HSC is represented by the use of bone marrow mesenchymal stromal cells (BM-MSCs) as a feeder to enhance HSC proliferation while maintaining HSC stemness. Indeed, BM-MSCs have been recognized as one of the most relevant players in the HSC niche. Thus, it has been hypothesized that they can support the ex vivo expansion of HSC by mimicking the physiological microenvironment present in the hematopoietic niche. Due to the role of placenta in supporting fetal hematopoiesis, MSC derived from the amniotic membrane (hAMSC) of human term placenta could represent an interesting alternative to BM-MSC as a feeder layer to enhance the proliferation and maintain HSC stemness. Therefore, in this study we investigated if hAMSC could support the ex vivo expansion of HSC and progenitor cells. The capacity of hAMSCs to support the ex vivo expansion of CB-HSC was evaluated in comparison to the control condition represented by the CB-CD34+ cells without a feeder layer. The coculture was performed at two different CD34+:MSC ratios (1:2 and 1:8) in both cell-to-cell contact and transwell setting. After 7 days, the cells were collected and analyzed for phenotype and functionality. Our results suggest that hAMSCs represent a valuable alternative to BM-MSC to support: (a) the ex vivo expansion of CB-HSC in both contact and transwell systems, (b) the colony forming unit ability, and (c) long-term culture initiating cells ability. Overall, these findings may contribute to address the unmet need of high HSC content in CB units available for transplantation
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