90 research outputs found
Polymorphisms of the NADPH Oxidase p22phox Gene in a Caucasian Population with Intracranial Aneurysms
Background: Vascular remodeling generated by reactive oxygen species contributes to aneurysm formation. The NADPH oxidase system is a major source of superoxide anion not only in phagocytes, but also in endothelial and vascular smooth muscle cells. Polymorphisms of p22phox, an essential component of the NADPH oxidase system, are found to be associated with atherosclerosis, while a recent study found a significant association between the 214C>T polymorphism and the occurrence of ischemic cerebrovascular disease. We conducted a case-control study to investigate the relationship of five polymorphisms of the p22phox gene and the occurrence of cerebral aneurysms. Methods: The study population consisted of 113 patients with intracranial aneurysms and 53 control subjects. The 214C>T polymorphism was investigated by restriction fragment length polymorphism analysis, while polymorphisms 381T>C, 480G>A, 521C>T, and *24A>G were analyzed by direct sequencing of exon 6 and adjacent intronic sequences. Results: The analysis of a primary study sample comprising 35 cases and 28 controls failed to show a significant association between any of the five polymorphisms and the occurrence of intracranial aneurysms using both allele frequencies and genotypes (all nominal p > 0.05). Although there was a deviation from Hardy-Weinberg equilibrium in cases at the 521C>T locus (nominal p T, 521C>T, and *24A>G); haplotype frequencies in cases and controls were not significantly different. Conclusion: Although polymorphisms of the p22phox gene located in the coding region and the 3′-untranslated region were reported to be associated with atherosclerosis and cerebrovascular disease, our data provide evidence that there is no association between these polymorphisms and the occurrence of cerebral aneurysms in Caucasians.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Association between TAS2R38 gene polymorphisms and colorectal cancer risk
Molecular sensing in the lingual mucosa and in the gastro-intestinal tract play a role in the detection of ingested harmful drugs and toxins. Therefore, genetic polymorphisms affecting the capability of initiating these responses may be critical for the subsequent efficiency of avoiding and/or eliminating possible threats to the organism. By using a tagging approach in the region of Taste Receptor 2R38 (TAS2R38) gene, we investigated all the common genetic variation of this gene region in relation to colorectal cancer risk with a case-control study in a German population (709 controls and 602 cases) and in a Czech population (623 controls and 601 cases). We found that there were no significant associations between individual SNPs of the TAS2R38 gene and colorectal cancer in the Czech or in the German population, nor in the joint analysis. However, when we analyzed the diplotypes and the phenotypes we found that the non-taster group had an increased risk of colorectal cancer in comparison to the taster group. This association was borderline significant in the Czech population, (OR = 1.28, 95% CI 0.99-1.67; P(value) = 0.058) and statistically significant in the German population (OR = 1.36, 95% CI 1.06-1.75; P(value) = 0.016) and in the joint analysis (OR = 1.34, 95% CI 1.12-1.61; P(value) = 0.001). In conclusion, we found a suggestive association between the human bitter tasting phenotype and the risk of CRC in two different populations of Caucasian origin
Проект узла гидрирования сернистых соединений
Конструирование аппарата для гидрирования сернистых соединений содержащихся в природном газе, а также исследование методов очистки природного газа.Designing an apparatus for hydrogenating sulfur compounds in natural gas, and studying methods for purifying natural gas
Value of upper gastrointestinal endoscopy for gastric cancer surveillance in patients with Lynch syndrome
In our study, we evaluated the effectiveness of upper gastrointestinal (GI) endoscopy as an instrument for early gastric cancer (GC) detection in Lynch syndrome (LS) patients by analyzing data from the registry of the German Consortium for Familial Intestinal Cancer. In a prospective, multicenter cohort study, 1128 out of 2009 registered individuals with confirmed LS underwent 5176 upper GI endoscopies. Compliance was good since 77.6% of upper GI endoscopies were completed within the recommended interval of 1 to 3 years. Forty-nine GC events were observed in 47 patients. MLH1 (n = 21) and MSH2 (n = 24) mutations were the most prevalent. GCs in patients undergoing regular surveillance were diagnosed significantly more often in an early-stage disease (UICC I) than GCs detected through symptoms (83% vs 25%; P = .0231). Thirty-two (68%) patients had a negative family history of GC. The median age at diagnosis was 51 years (range 28-66). Of all GC patients, 13 were diagnosed at an age younger than 45. Our study supports the recommendation of regular upper GI endoscopy surveillance for LS patients beginning no later than at the age of 30.
What's new?
Risk of gastric cancer (GC) is significantly increased among patients with Lynch syndrome (LS). GC screening in LS patients, however, is fraught with uncertainty, particularly regarding the use of esophagogastroduodenoscopy (EGD). The authors of this study investigated the use of EGD for regular GC surveillance in a German cohort of LS patients. Regular surveillance by EGD resulted in more frequent diagnosis and significant down-staging of GC, relative to detection via symptoms alone. In most cases, family history of GC was negative. This study supports recommendations for regular gastroscopic surveillance in LS patients starting by age 30
The apparent genetic anticipation in PMS2-associated Lynch syndrome families is explained by birth cohort effect
BACKGROUND: PMS2-associated Lynch syndrome is characterized by a relatively low colorectal cancer penetrance compared with other Lynch syndromes. However, age at colorectal cancer diagnosis varies widely, and a strong genetic anticipation effect has been suggested for PMS2 families. In this study, we examined proposed genetic anticipation in a sample of 152 European PMS2 families. METHODS: The 152 families (637 family members) that were eligible for analysis were mainly clinically ascertained via clinical genetics centers. We used weighted Cox-type random effects model, adjusted by birth cohort and sex, to estimate the generational effect on the age of onset of colorectal cancer. Probands and young birth cohorts were excluded from the analyses. Weights represented mutation probabilities based on kinship coefficients, thus avoiding testing bias. RESULTS: Family data across three generations, including 123 colorectal cancers, were analyzed. When compared with the first generation, the crude HR for anticipation was 2.242 [95% confidence interval (CI), 1.162-4.328] for the second generation and 2.644 (95% CI, 1.082-6.464) for the third generation. However, after correction for birth cohort and sex, the effect vanished [HR = 1.302 (95% CI, 0.648-2.619) and HR = 1.074 (95% CI, 0.406-2.842) for second and third generations, respectively]. CONCLUSIONS: Our study did not confirm previous reports of genetic anticipation in PMS2-associated Lynch syndrome. Birth-cohort effect seems the most likely explanation for observed younger colorectal cancer diagnosis in subsequent generations, particularly because there is currently no commonly accepted biological mechanism that could explain genetic anticipation in Lynch syndrome. IMPACT: This new model for studying genetic anticipation provides a standard for rigorous analysis of families with dominantly inherited cancer predisposition
Examination of Apoptosis Signaling in Pancreatic Cancer by Computational Signal Transduction Analysis
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer death. Changes in apoptosis signaling in pancreatic cancer result in chemotherapy resistance and aggressive growth and metastasizing. The aim of this study was to characterize the apoptosis pathway in pancreatic cancer computationally by evaluation of experimental data from high-throughput technologies and public data bases. Therefore, gene expression analysis of microdissected pancreatic tumor tissue was implemented in a model of the apoptosis pathway obtained by computational protein interaction prediction. METHODOLOGY/PRINCIPAL FINDINGS: Apoptosis pathway related genes were assembled from electronic databases. To assess expression of these genes we constructed a virtual subarray from a whole genome analysis from microdissected native tumor tissue. To obtain a model of the apoptosis pathway, interactions of members of the apoptosis pathway were analysed using public databases and computational prediction of protein interactions. Gene expression data were implemented in the apoptosis pathway model. 19 genes were found differentially expressed and 12 genes had an already known pathophysiological role in PDAC, such as Survivin/BIRC5, BNIP3 and TNF-R1. Furthermore we validated differential expression of IL1R2 and Livin/BIRC7 by RT-PCR and immunohistochemistry. Implementation of the gene expression data in the apoptosis pathway map suggested two higher level defects of the pathway at the level of cell death receptors and within the intrinsic signaling cascade consistent with references on apoptosis in PDAC. Protein interaction prediction further showed possible new interactions between the single pathway members, which demonstrate the complexity of the apoptosis pathway. CONCLUSIONS/SIGNIFICANCE: Our data shows that by computational evaluation of public accessible data an acceptable virtual image of the apoptosis pathway might be given. By this approach we could identify two higher level defects of the apoptosis pathway in PDAC. We could further for the first time identify IL1R2 as possible candidate gene in PDAC
Polymorphisms of genes coding for ghrelin and its receptor in relation to colorectal cancer risk: a two-step gene-wide case-control study
<p>Abstract</p> <p>Background</p> <p>Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHSR), has two major functions: the stimulation of the growth hormone production and the stimulation of food intake. Accumulating evidence also indicates a role of ghrelin in cancer development.</p> <p>Methods</p> <p>We conducted a case-control study to examine the association of common genetic variants in the genes coding for ghrelin (GHRL) and its receptor (GHSR) with colorectal cancer risk. Pairwise tagging was used to select the 11 polymorphisms included in the study. The selected polymorphisms were genotyped in 680 cases and 593 controls from the Czech Republic.</p> <p>Results</p> <p>We found two SNPs associated with lower risk of colorectal cancer, namely SNPs rs27647 and rs35683. We replicated the two hits, in additional 569 cases and 726 controls from Germany.</p> <p>Conclusion</p> <p>A joint analysis of the two populations indicated that the T allele of rs27647 SNP exerted a protective borderline effect (P<sub>trend </sub>= 0.004).</p
Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants: findings from the Prospective Lynch Syndrome Database
Lynch syndrome (LS) results from pathogenic variants in the mismatch repair (MMR) genes and is the most common hereditary cancer syndrome, affecting an estimated 1 in 300 individuals. Pathogenic variants in each of the MMR genes path_MLH1, path_MSH2, path_MSH6, and path_PMS2 result in different risks for cancers in organs including the colorectum, endometrium, ovaries, stomach, small bowel, bile duct, pancreas, and upper urinary tract. Accurate estimates of these risks are essential for planning appropriate approaches to the prevention or early diagnosis of cancers but the robustness of previous studies has been limited by factors including retrospective design,1,2 lack of validation in independent cohorts,3-5 and inconsistent classification of genetic variants. Unexpected findings from previous studies have included path_MLH1 and path_MSH2 carriers appearing to have a lifetime risk of colorectal cancer (CRC) of approximately 50%, despite surveillance colonoscopy,6-8 and that shorter intervals between colonoscopies do not seem to reduce the incidence of CRC in LS.9,10 These findings challenge the assumptions that CRC in LS usually develops from a noninfiltrative adenoma precursor and that CRC can be prevented by colonoscopic detection and removal of adenomas in the colon and rectum. Additionally, previous studies in the Prospective Lynch Syndrome Database (PLSD) have shown no increase in cancer risk in path_PMS2 carriers before 40 years of age and, although observation years were limited in older path_PMS2 carriers, LS-associated cancers other than endometrial and prostate were not observed.6-8 In this study we collected prospective data from a new large cohort of path_MMR carriers to validate previous findings from PLSD. We also updated information on the original cohort to ensure consistent classification of pathogenicity of MMR gene variants. We then combined both data sets, providing larger numbers that allowed us to derive more precise risk estimates for cancers in LS categorized by gene and gender
Correction:Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants: findings from the Prospective Lynch Syndrome Database
Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants:findings from the Prospective Lynch Syndrome Database
Purpose Pathogenic variants affecting MLH1, MSH2, MSH6, and PMS2 cause Lynch syndrome and result in different but imprecisely known cancer risks. This study aimed to provide age and organ-specific cancer risks according to gene and gender and to determine survival after cancer. Methods We conducted an international, multicenter prospective observational study using independent test and validation cohorts of carriers of class 4 or class 5 variants. After validation the cohorts were merged providing 6350 participants and 51,646 follow-up years. Results There were 1808 prospectively observed cancers. Pathogenic MLH1 and MSH2 variants caused high penetrance dominant cancer syndromes sharing similar colorectal, endometrial, and ovarian cancer risks, but older MSH2 carriers had higher risk of cancers of the upper urinary tract, upper gastrointestinal tract, brain, and particularly prostate. Pathogenic MSH6 variants caused a sex-limited trait with high endometrial cancer risk but only modestly increased colorectal cancer risk in both genders. We did not demonstrate a significantly increased cancer risk in carriers of pathogenic PMS2 variants. Ten-year crude survival was over 80% following colon, endometrial, or ovarian cancer. Conclusion Management guidelines for Lynch syndrome may require revision in light of these different gene and gender-specific risks and the good prognosis for the most commonly associated cancers
- …