Magnetically modified TiO2 powders - microstructure and magnetic properties

AbstractThe anatase (TiO2) particles magnetically modified by iron oxides and prepared by an innovating technological procedure are studied from the viewpoint of microstructure and a complex analysis of magnetic behaviour at room and elevated temperatures. Scanning electron microscopy observations have yielded variable shapes of particles in the composite powder whereas the iron oxide particles of diameter bellow 1μm were detected on the surface of the TiO2. The dominant magnetite (Fe3O4) accompanied by a small amount of maghemite (γ-Fe2O3) and/or hematite (α- Fe2O3) were analysed by X-ray powder diffraction. A relatively high saturation magnetization (3.38 Am2/kg), negative dipolar interactions, and the low values of reversible and irreversible part of magnetic susceptibility were found out from magnetic measurements at room temperature. During a thermomagnetic treatment the composite sample has been going through a few magnetic phase transitions and transforms into a fully paramagnetic state around 850K. After its cooling to the room temperature an undesirable magnetic hardening of the sample has occurred

Double-strand break repair and colorectal cancer: gene variants within 3' UTRs and microRNAs binding as modulators of cancer risk and clinical outcome

Genetic variations in 3' untranslated regions of target genes may affect microRNA binding, resulting in differential protein expression. microRNAs regulate DNA repair, and single-nucleotide polymorphisms in miRNA binding sites (miRSNPs) may account for interindividual differences in the DNA repair capacity. Our hypothesis is that miRSNPs in relevant DNA repair genes may ultimately affect cancer susceptibility and impact prognosis.In the present study, we analysed the association of polymorphisms in predicted microRNA target sites of double-strand breaks (DSBs) repair genes with colorectal cancer (CRC) risk and clinical outcome. Twenty-one miRSNPs in non-homologous end-joining and homologous recombination pathways were assessed in 1111 cases and 1469 controls. The variant CC genotype of rs2155209 in MRE11A was strongly associated with decreased cancer risk when compared with the other genotypes (OR 0.54, 95% CI 0.38-0.76, p = 0.0004). A reduced expression of the reporter gene was observed for the C allele of this polymorphism by in vitro assay, suggesting a more efficient interaction with potentially binding miRNAs. In colon cancer patients, the rs2155209 CC genotype was associated with shorter survival while the TT genotype of RAD52 rs11226 with longer survival when both compared with their respective more frequent genotypes (HR 1.63, 95% CI 1.06-2.51, p = 0.03 HR 0.60, 95% CI 0.41-0.89, p = 0.01, respectively). miRSNPs in DSB repair genes involved in the maintenance of genomic stability may have a role on CRC susceptibility and clinical outcome

Fusobacterium nucleatum tumor DNA levels are associated with survival in colorectal cancer patients

Made available in DSpace on 2019-10-06T17:16:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01There is increasing evidence indicating a role for Fusobacterium nucleatum (F. nucleatum) in colorectal cancer (CRC) development and prognosis. This study evaluated F. nucleatum as a prognostic biomarker, by assessing its association with post-diagnosis survival from CRC. From September 2008 to April 2012 CRC patients (n = 190) were recruited from three hospitals within the Czech Republic. F. nucleatum DNA copies were measured in adjacent non-malignant and colorectal tumor tissues using quantitative real-time PCR. Cox Proportional Hazards (HR) models were applied to evaluate the association between F. nucleatum DNA and overall survival, adjusting for key confounders. Risk prediction modeling was conducted to evaluate the ability to predict survival based on F. nucleatum status. High, compared with low, levels of F. nucleatum in colorectal tumor tissues were associated with poorer overall survival (adjusted HR 1.68, 95% CI 1.02–2.77), which was slightly attenuated after additional adjustment for microsatellite instability status. However, inclusion of F. nucleatum in risk prediction models did not improve the ability to identify patients who died beyond known prognostic factors such as disease pathology staging. Although the increased presence of F. nucleatum was associated with poorer prognosis in CRC patients, this may have limited clinical relevance as a prognostic biomarker.Centre for Public Health Queen’s University BelfastDepartment of Biology São Paulo State University UNESPInstitute of Biology and Medical Genetics First Faculty of Medicine Charles UniversityDepartment of Molecular Biology of Cancer Institute of Experimental Medicine of the Czech Academy of SciencesDepartment of Surgery General University Hospital in PragueDepartment of Surgery First Faculty of Medicine Charles University and Thomayer HospitalBiomedical Centre Faculty of Medicine in Pilsen Charles UniversityDepartment of Oncology First Faculty of Medicine Charles University and Thomayer HospitalCancer Biology and Therapeutics Group School of Biomolecular and Biomedical Science UCD Conway Institute University College DublinDepartment of Biology São Paulo State University UNES

Dysbiosis of Skin Microbiota in Psoriatic Patients: Co-occurrence of Fungal and Bacterial Communities

Psoriasis is a chronic inflammatory skin disease, whose pathogenesis involves dysregulated interplay among immune cells, keratinocytes and environmental triggers, including microbiota. Bacterial and fungal dysbiosis has been recently associated with several chronic immune-mediated diseases including psoriasis. In this comprehensive study, we investigated how different sampling sites and methods reflect the uncovered skin microbiota composition. After establishing the most suitable approach, we further examined correlations between bacteria and fungi on the psoriatic skin. We compared microbiota composition determined in the same sample by sequencing two distinct hypervariable regions of the 16S rRNA gene. We showed that using the V3V4 region led to higher species richness and evenness than using the V1V2 region. In particular, genera, such as Staphylococcus and Micrococcus were more abundant when using the V3V4 region, while Planococcaceae, on the other hand, were detected only by the V1V2 region. We performed a detailed analysis of skin microbiota composition of psoriatic lesions, unaffected psoriatic skin, and healthy control skin from the back and elbow. Only a few discriminative features were uncovered, mostly specific for the sampling site or method (swab, scraping, or biopsy). Swabs from psoriatic lesions on the back and the elbow were associated with increased abundance of Brevibacterium and Kocuria palustris and Gordonia, respectively. In the same samples from psoriatic lesions, we found a significantly higher abundance of the fungus Malassezia restricta on the back, while Malassezia sympodialis dominated the elbow mycobiota. In psoriatic elbow skin, we found significant correlation between occurrence of Kocuria, Lactobacillus, and Streptococcus with Saccharomyces, which was not observed in healthy skin. For the first time, we showed here a psoriasis-specific correlation between fungal and bacterial species, suggesting a link between competition for niche occupancy and psoriasis. However, it still remains to be elucidated whether observed microbial shift and specific inter-kingdom relationship pattern are of primary etiological significance or secondary to the disease

Coding variants in NOD-like receptors: An association study on risk and survival of colorectal cancer

Nod-like receptors (NLRs) are important innate pattern recognition receptors and regulators of inflammation or play a role during development. We systematically analysed 41 non-synonymous single nucleotide polymorphisms (SNPs) in 21 NLR genes in a Czech discovery cohort of sporadic colorectal cancer (CRC) (1237 cases, 787 controls) for their association with CRC risk and survival. Five SNPs were found to be associated with CRC risk and eight with survival at 5% significance level. In a replication analysis using data of two large genome-wide association studies (GWASs) from Germany (DACHS: 1798 cases and 1810 controls) and Scotland (2210 cases and 9350 controls) the associations found in the Czech discovery set were not confirmed. However, expression analysis in human gut-related tissues and immune cells revealed that the NLRs associated with CRC risk or survival in the discovery set were expressed in primary human colon or rectum cells, CRC tissue and/or cell lines, providing preliminary evidence for a potential involvement of NLRs in general in CRC development and/or progression. Most interesting was the finding that the enigmatic development-related NLRP5 (also known as MATER) was not expressed in normal colon tissue but in colon cancer tissue and cell lines. Future studies may show whether regulatory variants instead of coding variants might affect the expression of NLRs and contribute to CRC risk and survival

Genotype and Haplotype Analyses of <i>TP53</i> Gene in Breast Cancer Patients: Association with Risk and Clinical Outcomes

<div><p>Variations in the <i>TP53</i> gene have been suggested to play a role in many cancers, including breast. We previously observed an association between <i>TP53</i> haplotypes based on four polymorphisms (rs17878362, rs1042522, rs12947788, and rs17884306) and the risk of colorectal and pancreatic cancer. Based on these results, in the present study, we have investigated the same polymorphisms and their haplotypes in 705 breast cancer cases and 611 healthy controls in relation to the disease risk, histopathological features of the tumor and clinical outcomes. In comparison to the most common haplotype A₁-G-C-G, all the other identified haplotypes were globally associated with a significantly decreased breast cancer risk (P = 0.006). In particular, the A₂-G-C-G haplotype was associated with a marked decreased risk of breast cancer when compared with the common haplotype (P = 0.0001). Moreover, rs1042522 in patients carrying the GC genotype and receiving only the anthracycline-based chemotherapy was associated with both overall and disease-free survival (recessive model for overall survival HR = 0.30 95% CI 0.11–0.80, P = 0.02 and for disease-free survival HR = 0.42 95% CI 0.21–0.84, P = 0.01). Present results suggest common genetic features in the susceptibility to breast and gastrointestinal cancers in respect to <i>TP53</i> variations. In fact, similar haplotype distributions were observed for breast, colorectal, and pancreatic patients in associations with cancer risk. Rs1042522 polymorphism (even after applying the Dunn-Bonferroni correction for multiple testing) appears to be an independent prognostic marker in breast cancer patients.</p></div

Short article : Influence of regulatory NLRC5 variants on colorectal cancer survival and 5-fluorouracil-based chemotherapy

Background NLRC5 is an interferon γ-inducible protein, which plays a role in immune surveillance with a potential influence on cancer survival. Objective We aimed to evaluate the effect of potential regulatory variants in NLRC5 on overall survival and survival after 5-fluorouracil (5-FU)-based therapy of colorectal cancer (CRC) patients. Patients and methods We carried out a case-only study in a Czech population of 589 cases; 232 received 5-FU-based therapy. Eleven variants within NLRC5 were selected using in-silico tools. Associations between polymorphisms and survival were assessed by Cox regression analysis adjusting for age at diagnosis, sex, and TNM stage. Survival curves were derived using the Kaplan-Meier method. Results Two variants showed a significant association with survival. All patients and metastasis-free patients at the time of diagnosis (pM0) who were homozygous carriers of the minor allele of rs27194 had a decreased overall survival (OS all and OS pM0) and event-free survival (EFS pM0) under a recessive model (OS all P=0.003, OS pM0 P=0.005, EFS pM0 P=0.01, respectively). OS was also decreased for all patients and for pM0 patients who carried at least one minor allele of rs289747 (OS all P=0.03 and OS pM0 P=0.003, respectively). Among CRC patients, who underwent a 5-FU-based adjuvant regimen, rs12445252 was associated with OS all, OS pM0 and EFS pM0, according to the dosage of the minor allele T (OS all P=0.0004, OS pM0 P=0.0001, EFS pM0 P=0.008, respectively). Conclusion Our results showed that polymorphisms in NLRC5 may be used as prognostic markers of survival of CRC patients, as well as for survival in response to 5-FU treatment

OS and DFS in relation to haplotype distributions (Cox regression).

<p>^aLoci rs17878362, rs1042522, rs12947788, rs17884306.</p><p>^b Number of alleles are reported. Because each individual has two alleles, the total number of alleles is twice the total number of individuals. Individuals with missing haplotype data were not included in the analyses.</p><p>^cAllele A₂ carries the 16-bp insertion within intron 3</p><p>HR, hazard ratio; 95% CI, confidence interval. Significant results in bold.</p><p>OS and DFS in relation to haplotype distributions (Cox regression).</p

<i>TP53</i> haplotype distribution between BC patients and controls.

<p>^aLoci rs17878362, rs1042522, rs12947788, rs17884306.</p><p>^bNumber of alleles are reported. Because each individual has two alleles, the total number of alleles will be twice the total number of individuals. Individuals with missing haplotype data were not included in the analyses.</p><p>^cAdjusted for age.</p><p>^dAllele A₂ carries the 16-bp insertion within intron 3</p><p>OR, odds ratio; CI, confidence interval. Significant P-values are in bold.</p><p><i>TP53</i> haplotype distribution between BC patients and controls.</p