64 research outputs found
Land use planning using Geographical Information System (GIS) techniques (Case study: Kalaleh & Darana watershed, North of Iran)
Flooding prioritization of Pol-Doab Shazand sub-catchments using hydrologic and statistical models
COX2 genetic variation, NSAIDs, and advanced prostate cancer risk
Collective evidence suggests that cyclooxygenase 2 (COX2) plays a role in prostate cancer risk. Cyclooxygenase 2 is the major enzyme that converts arachidonic acid to prostaglandins, which are potent mediators of inflammation. Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the enzymatic activity of COX2 and long-term use of NSAIDs appears to modestly lower the risk of prostate cancer. We investigated whether common genetic variation in COX2 influences the risk of advanced prostate cancer. Nine single-nucleotide polymorphisms (SNPs) in COX2 were genotyped among 1012 men in our case–control study of advanced prostate cancer. Gene–environment interactions between COX2 polymorphisms and NSAID use were also evaluated. Information on NSAID use was obtained by questionnaire. Three SNPs demonstrated nominally statistically significant associations with prostate cancer risk, with the most compelling polymorphism (rs2745557) associated with a lower risk of disease (odds ratio (OR) GC vs GG=0.64; 95% confidence interval (CI): 0.49–0.84; P=0.002). We estimated through permutation analysis that a similarly strong result would occur by chance 2.7% of the time. Nonsteroidal anti-inflammatory drug use was associated with a lower risk of disease in comparison to no use (OR=0.67; 95% CI: 0.52–0.87). No significant statistical interaction between NSAID use and rs2745557 was observed (P=0.12). Our findings suggest that variation in COX2 is associated with prostate cancer risk
Prophylactic Mastectomy in BRCA1/2 Mutation Carriers and Women at Risk of Hereditary Breast Cancer: Long-Term Experiences at the Rotterdam Family Cancer Clinic
Background BRCA1/2 mutation carriers and women from a hereditary breast(/ovarian) cancer family have a highly increased risk of developing
breast cancer (BC). Prophylactic mastectomy (PM) results in the greatest BC risk reduction. Long-term data on the efficacy
and sequels of PM are scarce.
Methods From 358 high-risk women (including 236 BRCA1/2 carriers) undergoing PM between 1994 and 2004, relevant data on the occurrence
of BC in relation to PM, complications in relation to breast reconstruction (BR), mutation status, age at PM and preoperative
imaging examination results were extracted from the medical records, and analyzed separately for women without (unaffected,
n = 177) and with a BC history (affected, n = 181).
Results No primary BCs occurred after PM (median follow-up 4.5 years). In one previously unaffected woman, metastatic BC was detected
almost 4 years after PM (primary BC not found). Median age at PM was younger in unaffected women (P < .001), affected women more frequently were 50% risk carriers (P < .001). Unexpected (pre)malignant changes at PM were found in 3% of the patients (in 5 affected, and 5 unaffected women,
respectively). In 49.6% of the women opting for BR one or more complications were registered, totaling 215 complications,
leading to 153 surgical interventions (71%). Complications were mainly related to cosmetic outcome (36%) and capsular formation
(24%).
Conclusions The risk of developing a primary BC after PM remains low after longer follow-up. Preoperative imaging and careful histological
examination is warranted because of potential unexpected (pre)malignant findings. The high complication rate after breast
reconstruction mainly concerns cosmetic issues
Assembly of Inflammation-Related Genes for Pathway-Focused Genetic Analysis
Recent identifications of associations between novel variants in inflammation-related genes and several common diseases emphasize the need for systematic evaluations of these genes in disease susceptibility. Considering that many genes are involved in the complex inflammation responses and many genetic variants in these genes have the potential to alter the functions and expression of these genes, we assembled a list of key inflammation-related genes to facilitate the identification of genetic associations of diseases with an inflammation-related etiology. We first reviewed various phases of inflammation responses, including the development of immune cells, sensing of danger, influx of cells to sites of insult, activation and functional responses of immune and non-immune cells, and resolution of the immune response. Assisted by the Ingenuity Pathway Analysis, we then identified 17 functional sub-pathways that are involved in one or multiple phases. This organization would greatly increase the chance of detecting gene-gene interactions by hierarchical clustering of genes with their functional closeness in a pathway. Finally, as an example application, we have developed tagging single nucleotide polymorphism (tSNP) arrays for populations of European and African descent to capture all the common variants of these key inflammation-related genes. Assays of these tSNPs have been designed and assembled into two Affymetrix ParAllele customized chips, one each for European (12,011 SNPs) and African (21,542 SNPs) populations. These tSNPs have greater coverage for these inflammation-related genes compared to the existing genome-wide arrays, particularly in the African population. These tSNP arrays can facilitate systematic evaluation of inflammation pathways in disease susceptibility. For additional applications, other genotyping platforms could also be employed. For existing genome-wide association data, this list of key inflammation-related genes and associated subpathways can facilitate comprehensive inflammation pathway- focused association analyses
Polymorphisms in regulatory regions of Cyclooxygenase-2 gene and breast cancer risk in Brazilians: a case-control study
<p>Abstract</p> <p>Background</p> <p>Cyclooxygenase-2 (COX-2) is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Here, we evaluate the association between single-nucleotide polymorphisms (SNPs) in the COX-2 gene (<it>PTGS2</it>) and the occurrence of breast cancer among Brazilian women.</p> <p>Methods</p> <p>The study was conducted prospectively in two steps: First, we screened the promoter region and three fragments of the 3'-untranslated region of <it>PTGS2 </it>from 67 healthy Brazilians to identify SNPs and to select those with a minor allele frequency (MAF) of at least 0.10. The MAF of these selected SNPs was further characterized in 402 healthy volunteers to evaluate potential differences related to heterogeneous racial admixture and to estimate the existence of linkage disequilibrium among the SNPs. The second step was a case-control study with 318 patients and 273 controls designed to evaluate <it>PTGS2 </it>genotype- or haplotype-associated risk of breast cancer.</p> <p>Results</p> <p>The screening analysis indicated nine SNPs with the following MAFs: rs689465 (0.22), rs689466 (0.15), rs20415 (0.007), rs20417 (0.32), rs20419 (0.015), rs5270 (0.02), rs20424 (0.007), rs5275 (0.22) and rs4648298 (0.01). The SNPs rs689465, rs689466, rs20417 and rs5275 were further studied: Their genotypic distributions followed Hardy-Weinberg equilibrium and the MAFs were not affected by gender or skin color. Strong linkage disequilibrium was detected for rs689465, rs20417 and rs5275 in the three possible pairwise combinations. In the case-control study, there was a significant increase of rs5275TC heterozygotes in cases compared to controls (OR = 1.44, 95% CI = 1.01-2.06; P = 0.043), and the haplotype formed by rs689465G, rs689466A, rs20417G and rs5275C was only detected in cases. The apparent association with breast cancer was not confirmed for rs5275CC homozygotes or for the most frequent rs5275C-containing haplotypes.</p> <p>Conclusions</p> <p>Our results indicate no strong association between the four most frequent <it>PTGS2 </it>SNPs and the risk of breast cancer.</p
WSES Guidelines for the management of acute left sided colonic diverticulitis in the emergency setting
Increased risk of contralateral breast cancers among overweight and obese women: a time-dependent association
WSES Guidelines for the management of acute left sided colonic diverticulitis in the emergency setting
Acute left sided colonic diverticulitis is one of the most common clinical conditions encountered by surgeons in acute setting. A World Society of Emergency Surgery (WSES) Consensus Conference on acute diverticulitis was held during the 3rd World Congress of the WSES in Jerusalem, Israel, on July 7th, 2015. During this consensus conference the guidelines for the management of acute left sided colonic diverticulitis in the emergency setting were presented and discussed. This document represents the executive summary of the final guidelines approved by the consensus conference.Peer reviewe
Hillslope hydrological modeling : the role of bedrock geometry and hillslope-stream interaction
Keywords: Hillslope hydrology, hydrological modeling, bedrock geometry, boundary condition, numerical solution. This thesis focuses on hillslope subsurface flow as a dominant control on the hydrological processes defining the catchment response to rainfall. Due to the difficulties associated with the three-dimensional equations, both in complexity and regarding the computational demand, focus is on 1D physically-based hillslope groundwater flow models. The main core of this research is to study how the simulated hillslope response, and specifically runoff generation, is affected by different simplifying assumptions concerning hillslope geometry and boundary conditions. Several generalizations have been made to incorporate the complexity of bedrock geometry in models of the hillslope hydrological response. In order to handle and compare these different models, a general and flexible numerical algorithm has been developed. Through the proposed numerical scheme several applications of these models are performed: (a) to investigate the role of the hillslope lower boundary condition on the groundwater response, (b) to study the role of bedrock geometry on the hillslope hydrological response, and (c) to approximate the hillslope response using the quasi-steady state approximation. Evaluation of the numerical scheme shows that it is flexible and capable to handle all these different models, which have been applied for different purposes, and that the mass balance is preserved. Evaluation of the developed models leads to the following general conclusions: (a) A head-discharge relationship as the hillslope lower boundary condition is a proper approach to model the coupled hillslope-stream system; (b) The recession characteristics of hillslopes depend on their bedrock profiles and local minima and maxima in the curved bedrock profile influence the groundwater head for small rainfall intensities; (c) The quasi-steady state approximation proves to be a simple but adequate method (both as a model and regarding computation time) to simulate the groundwater dynamics of hillslopes. In summary, this thesis aims to understand theoretically how hydrological processes (subsurface flow and water table dynamics) react to bedrock complexity and the hillslope lower boundary condition. The presented numerical scheme can be applied in many investigations of hillslope hydrology because of its generality and flexibility. <br/
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