15 research outputs found
Incidence of Genotypes of Helicobacter Pylori in Oropharyngeal SCC
Helicobacter pylori (HP) is a well known gastric pathogen which has been recently detected in the oral cavity and saliva an also in oropharynx, especially in adenoid and tonsillar tissue (WladayerĂ´s ring tissue). Presented research has been focused on real-time PCR analyzing cagA and vacA genotypes of HP strains in tonsills and oropharyngeal cancer.
Methods The study was approved by the appropriate ethics committee.The tissue specimens of tonsillar cancer or tonsils were collected using sterile instruments at the beginning of surgery.Biopsies were immersed into Remel MicrotestR M4RT and transported to the laboratory for real-time PCR analysis. TaqManTM hybridisation probes were developed for cagA , , vacA m1 and vacA m2, LC hybridization probes for vacA s1a, vacA s1b, vacA s2 specific sequence detection.
Findings
Majority of isolates lacking cagA gene coding CagA protein as the main factor of Helicobacter pylori pathogenicity as well as one type of vacA gene s1b m2 found in 17 from a total of 41 isolates (41.46 %) and in 66.66 % of tonsillar cancer.
Interpretation
Colonization of lymphoid tissue and malignancies in oropharyngeal area by different genotypes of Helicobacter pylori seems to be evident. Long-term survival of bacteria in deep tissue structures may influence immune system
Potential of Advanced Consolidants for the Application on Sandstone
Alkoxy-based consolidants are widely used for conservation of cultural heritage objects made from sandstones. Even if such consolidants were introduced into practice already in the 19th century, their performance has been enhanced by several modifications to their composition only recently. To obtain a relevant comparison of their application potential, both commercial (Remmers KSE OH and SurfaPore FX SB) and a self-developed particle-modified ethyl silicate consolidant supplemented with two phosphate-based ones, were assessed. Importantly, the potential toxicity of our novel consolidants was considered. Since the stone substrate should mimic the properties of naturally weathered stone, sandstone from the Msene quarry in Central Bohemia, characterized by a high porosity and relatively low mechanical strength, is selected. From practical point of view, the long-term durability of the consolidation effect is crucial compared to the initial level of consolidation. Regarding the determination of durability of the sandstone consolidation according to an American Society for Testing and Materials (ASTM) accelerated weathering test, we performed mechanical tests in micro- (nanoindentation) and macroscale (drilling resistance measurements). The cohesion of the consolidant xerogels in the pores were determined by sorption experiments in gas phase. The durability of our TiO2 and ZnO particle-modified consolidants is superior to that of the commercial products. The aqueous diammonium hydrogen phosphate-based consolidant, which also shows exceptional durability, reveals itself to be a promising product for not only carbonate but also sandstone materials
The Role of NBI HDTV Magnifying Endoscopy in the Prehistologic Diagnosis of Laryngeal Papillomatosis and Spinocellular Cancer
Narrow band imaging (NBI) HDTV (high definition television) magnifying endoscopy is considered to be superior for the accurate display of the microvascular patterns of superficial mucosal lesions. Observation of changes in intraepithelial papillary capillary loops (IPCL) can help distinguish benign from malignant lesions as part of an âoptical biopsy.â However, IPCL changes in papillomas may be mistaken for spinocellular cancer (SCC). The aim of the study was to determine whether observing microvascular changes alone is sufficient for discriminating between laryngeal SCC and papillomatosis. An additional aim was to identify associated characteristics that could clarify the diagnosis. The study included 109 patients with a suspected laryngeal tumor or papilloma. HDTV NBI magnifying endoscopy was performed during direct laryngoscopy. It was possible to visualize IPCL changes in 82 out of 109 patients (75.2%). In 71 (86.6%) patients, the diagnosis was correctly determined. In 4 (4.9%) cases, the diagnosis of SCC was expressed on the basis of finding pathologic IPCL, but histology did not demonstrate malignancy. To achieve a correct diagnosis using HDTV NBI magnifying endoscopy, it is important not only to observe changes in the shape of IPCL but also to note possible papillary structures with central-axis capillaries typical of papillomatosis
Physico-chemical properties of PDMS surfaces suitable as substrates for cell cultures
Elastic properties of the substrate have profound effect on adhesion and proliferation of cells. Here, we introduce a method to produce polydimethylsiloxane (PDMS) substrates with stiffness tuned monotonically from 1.67 to 0.24 MPa, by the time of UV irradiation adjusted up to 5 h. The Youngâs modulus (determined by using nanoindenter) scales linearly with stiffness calculated using AFM-based force spectroscopy data. Such a relation enables the determination of the Young modulus from AFM force â distance curves also when the Herz model is not applicable. Our findings demonstrate that surface properties of PDMS substrates are not affected by the applied methodology of tuning substrate elasticity. Finally, the colorimetric proliferation assay (MTT) carried out for non-malignant (HCV29) and cancerous (T24) bladder cancer cells depicted a significant contribution of PDMS substrate elasticity to the behavior of cells. The softer PDMS substrate demonstrated excellent cytocompatibility whereas the stiff one is more cell-repellent