1. Quantitative aspects of ToF-SIMS analysis of metals and alloys in a UHV, O2 and H2 atmosphereJernej Ekar, Saša Kos, Janez Kovač, 2024, izvirni znanstveni članek Povzetek: Although secondary ion mass spectrometry (SIMS) is a versatile method used in the fields of surface analysis, depth profiling and elemental and molecular mapping, it also lacks quantification capabilities. The main reason for this is the matrix effect, which influences the ionization yield of secondary ions with respect to the substrate from which the analyzed compounds originate. There are several approaches to reduce the matrix effect, and gas flooding is one of the easiest methods to apply. In this work, we have investigated the possibilities of the ToF-SIMS method for the quantification of selected metals and alloys containing these metals in different ratios by reducing the matrix effect in the presence of different atmospheres. The measurements were performed in the ultra-high vacuum (UHV) environment, H2 and O2 atmospheres. H2 flooding shows the most significant improvements compared to the UHV analysis, while O2 is also promising but has some limitations. Improvements are most evident for the transition metals Ti, Cr, Fe, Co and Ni employed in our study, while the p-block elements such as Al and Si do not change so extensively. The deviations from the true atomic ratios of selected transition metals in different alloys reach a maximum of only 46 % when analyzed in the H2 atmosphere. In contrast, these values are 66 and 228 % for the O2 atmosphere and UHV environment, respectively. Our results suggest that gas adsorption and consequent formation of a new matrix on the surface, especially in the case of hydrogen, reduces the differences between the different chemical environments and electronic structures of the surface. In this way, the quantitative aspects of the SIMS method can be improved.
Ključne besede: ToF-SIMS quantification, H2 and O2 gas flooding, matrix effect reduction, cluster secondary ions
Objavljeno v DiRROS: 15.05.2024; Ogledov: 72; Prenosov: 36
 Celotno besedilo (1,15 MB) |
2. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruptionShirley Sharabi, Bor Kos, David Last, David Guez, Dianne Daniels, Sagi Harnof, Yael Mardor, Damijan Miklavčič, 2016, izvirni znanstveni članek Ključne besede: electroporation, blood brain barrier, Peleg-Fermi
Objavljeno v DiRROS: 09.05.2024; Ogledov: 69; Prenosov: 40
Celotno besedilo (721,66 KB)
Gradivo ima več datotek! Več... |
3. |
4. Quantitative aspects of ToF-SIMS analysis of metals and alloys in a UHV, O2 and H2 atmosphereJernej Ekar, Saša Kos, Janez Kovač, 2024, izvirni znanstveni članek Ključne besede: ToF-SIMS kvantifikacija, kovine, matrični efekt, preplavljanje, atmosferski plini
Objavljeno v DiRROS: 09.05.2024; Ogledov: 71; Prenosov: 33
Celotno besedilo (1,15 MB) |
5. |
6. Gamma-enolase : a well known tumour marker, with a less-known role in cancerTjaša Vižin, Janko Kos, 2015, pregledni znanstveni članek Povzetek: Gamma-enolase, known also as neuron-specific enolase (NSE), is an enzyme of the glycolytic pathway, which is expressed predominantly in neurons and cells of the neuroendocrine system. As a tumour marker it is used in diagnosis and prognosis of cancer; however, the mechanisms enrolling it in malignant progression remain elusive. As a cytoplasmic enzyme gamma-enolase is involved in increased aerobic glycolysis, the main source of energy in cancer cells, supporting cell proliferation. However, different cellular localisation at pathophysiological conditions, proposes other cellular engagements. The C-terminal part of the molecule, which is not related to glycolytic pathway, was shown to promote survival of neuronal cells by regulating neuronal growth factor receptor dependent signalling pathways, resulting also in extensive actin cytoskeleton remodelling. This additional function could be important also in cancer cells either to protect cells from stressful conditions and therapeutic agents or to promote tumour cell migration and invasion. Gamma-enolase might therefore have a multifunctional role in cancer progression: it supports increased tumour cell metabolic demands, protects tumour cells from stressful conditions and promotes their invasion and migration.
Ključne besede: gamma-enolase, cancer, glycolysis, cell survival, tumour marker
Objavljeno v DiRROS: 23.04.2024; Ogledov: 92; Prenosov: 46
Celotno besedilo (864,48 KB)
Gradivo ima več datotek! Več... |
7. The cost of systemic therapy for metastatic colorectal carcinoma in Slovenia : discrepancy analysis between cost and reimbursementTanja Mesti, Biljana Mileva Boshkoska, Mitja Kos, Metka Tekavčič, Janja Ocvirk, 2015, izvirni znanstveni članek Povzetek: The aim of the study was to estimate the direct medical costs of metastatic colorectal cancer (mCRC) treated at the Institute of Oncology Ljubljana and to question the healthcare payment system in Slovenia. Methods. Using an internal patient database, the costs of mCRC patients were estimated in 2009 by examining (1) mCRC direct medical related costs, and (2) the cost difference between payment received by Slovenian health insurance and actual mCRC costs. Costs were analysed in the treatment phase of the disease by assessing the direct medical costs of hospital treatment with systemic therapy together with hospital treatment of side effects, without assessing radiotherapy or surgical treatment. Follow-up costs, indirect medical costs, and nonmedical costs were not included. Results. A total of 209 mCRC patients met all eligibility criteria. The direct medical costs of mCRC hospitalization with systemic therapy in Slovenia for 2009 were estimated as the cost of medications (cost of systemic therapy + cost of drugs for premedication) + labor cost (the cost of carrying out systemic treatment) + cost of lab tests + cost of imaging tests + KRAS testing cost + cost of hospital treatment due to side effects of mCRC treatment, and amounted to %3,914,697. The difference between the cost paid by health insurance and actual costs, estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009, was %1,900,757.80. Conclusions. The costs paid to the Institute of Oncology Ljubljana by health insurance for treating mCRC with systemic therapy do not match the actual cost of treatment. In fact, the difference between the payment and the actual cost estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009 was %1,900,757.80. The model Australian Refined Diagnosis Related Groups (AR-DRG) for cost assessment in oncology being currently used is probably one of the reasons for the discrepancy between pay-outs and actual costs. We propose new method for more precise cost assessment in oncology.
Ključne besede: cost of treatment, metastatic colorectal cancer, cost of targeted therapy, monitoring costs
Objavljeno v DiRROS: 17.04.2024; Ogledov: 150; Prenosov: 39
Celotno besedilo (730,95 KB) |
8. Inhibition of cathepsin X enzyme influences the immune response of THP-1 cells and dendritic cells infected with Helicobacter pyloriMiha Skvarč, David Štubljar, Andreja Nataša Kopitar, Samo Jeverica, Bojan Tepeš, Janko Kos, Alojz Ihan, 2013, izvirni znanstveni članek Povzetek: Background. The immune response to Helicobacter pylori importantly determines the outcome of infection as well as the success of eradication therapy. We demonstrate the role of a cysteine protease cathepsin X in the immune response to H. pylori infection. Materials and methods. We analysed how the inhibition of cathepsin X influenced the immune response in experiments when THP-1 cells or dendritic cells isolated from patients were stimulated with 48 strains of H. pylori isolated from gastric biopsy samples of patients which had problems with the eradication of bacteria. Results. The experiments, performed with the help of a flow cytometer, showed that the expression of Toll-like receptors (TLRs), especially TLR-4 molecules, on the membranes of THP-1 cells or dendritic cells was higher when we stimulated cells with H. pylori together with inhibitor of cathepsin X 2F12 compared to THP-1 cells or dendritic cells stimulated with H. pylori only, and also in comparison with negative control samples. We also demonstrated that when we inhibited the action of cathepsin X in THP-1 cells, the concentrations of pro-inflammatory cytokines were lower than when THP-1 cell were stimulated with H. pylori only. Conclusions. We demonstrated that inhibition of cathepsin X influences the internalization of TLR-2 and TLR-4. TLR-2 and TLR-4 redistribution to intra-cytoplasmic compartments is hampered if cathepsin X is blocked. The beginning of a successful immune response against H. pylori in the case of cathepsin X inhibition is delayed.
Ključne besede: cathepsin X, macrophage, dendritic cells
Objavljeno v DiRROS: 22.03.2024; Ogledov: 107; Prenosov: 49
Celotno besedilo (564,38 KB)
Gradivo ima več datotek! Več... |
9. |
10. Cathepsin X in serum from patients with colorectal cancer: relation to prognosisTjaša Vižin, Ib Jarle Christensen, Hans Jørgen Nielsen, Janko Kos, 2012, izvirni znanstveni članek Povzetek: Background. Up-regulation of lysosomal cysteine protease cathepsin X (Cat X) is associated with disorders of the immune system and neurodegenerative diseases, while its role in the development and progression of cancer is less understood. Enhanced secretion of pro-Cat X was observed in malignant processes, and therefore, the level of total serum Cat X rather than the active enzyme may better reflect the tumour status. Patients and methods. Seventy-seven patients with colorectal cancer (CRC) were included in a retrospective study. Blood samples were collected prior to therapy. Using ELISA, the values of total Cat X were measured in serum. Groups of healthy persons (n=77), patients with adenomas (n=77) and patients with non-neoplastic findings (n=77) were included. Results. Significant differences between the group of colorectal patients and the groups of healthy persons, adenoma patients and patients with non-malignant findings could not be shown (p=0.89). Within the group of CRC, higher levels of total Cat X significantly correlated to shorter overall survival (HR=2.08, 95% CI:1.07-4.05, p=0.028). Conclusions. Total serum Cat X could be a useful prognostic indicator for determining survival of patients with CRC. Increased serum levels of total CatX may reflect more aggressive tumour cell phenotypes and suggest the involvement of Cat X in processes involved in later stages of tumour progression.
Ključne besede: cysteine cathepsins, cathepsin X, colorectal cancer, prognosis, serum biomarker
Objavljeno v DiRROS: 21.03.2024; Ogledov: 124; Prenosov: 69
Celotno besedilo (360,31 KB)
Gradivo ima več datotek! Več... |
