1271. Phase II study of fluorouracil, leucovorin and interferon alpha-2a in patients with advanced colon cancerBorut Štabuc, Aleksandra Markovič, Erik Brecelj, Samir Bešlija, Tomaž-Edvard Cizej, 1998, izvirni znanstveni članek Povzetek: Based on in viro studies that have demonstrated synergy between fluorouracil (5-FU) and leucovorin (LV) as well as between 5-FU and recombinant alpha-2a interferon (IFN) against colon cancer cell lines a phase II study was carried out to evaluate the toxicity and clinical activity of 5-FU modulated with LV and IFN in patients with metastatic colon cancer. Twenty-two chemotherapy naive patients with measurable metastases of colon cancer have been treated with daily doses of 5-FU 600 mg/m2 in 6-hr intravenous infusion, and of LV 20 mg/m2 intravenously and IFN 6 MU subcutaneously, for 5 days every 4 weeks. Median age was 60 years, median PS (ECOG) was 1 (range 0-2). Liver, soft tissue and lung metastases were found in 12, 5 and 8 patients, respectively. Nineteen patients had a single metastatic site, two double, whereas one had more than two metastatic sites. Patients had 2-9 (mean 5) cycles of treatment.Objective response was observed in 7 patients (32%), and stable disease in 7 patients (32%). Overall median survival was 12.5 months, and for responders 14.4 months. Responses were generally short and median time for progression was 5.5 months. The most frequent adverse reactions were flu-like syndrome (50%), nausea/vomiting (36%), diarhoea (13Č), stomatitis (27%) and leucopenia (13%). This regimen of 5-FU with LV and IFN administration does notappear to be superior to previously published shedules of 5-FU with IFN or 5-FU with LV. Objavljeno v DiRROS: 19.01.2024; Ogledov: 289; Prenosov: 87
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1272. Experimental and numerical investigation of restrained shrinkage of concreteLucija Hanžič, Jurij Karlovšek, Tomaž Hozjan, Sabina Huč, Zhongyu Xu, Igor Planinc, Johnny Ching Ming Ho, 2020, objavljeni znanstveni prispevek na konferenci Povzetek: To promote the understanding of shrinkage related behaviour of concrete used for tunnel linings the experimental and theoretical investigation including numerical and analytical approach was performed on ring-shaped specimens. Overall one analytical (an.) and two numerical models, namely (i) and (ii) were also developed. Models (an.) and (i) considered the restraining steel ring to be rigid, thus not exhibiting any deformation. Numerical model (ii) considered the steel ring to be deformable. The experimental set-up consisted of a large concrete ring with an inner diameter of 120 cm, an outer diameter of 160cm and 20 cm in height. The restraining steel ring was 5.5 cm thick. Two concrete rings were made, namely R1 with a low compressive strength of ~26MPa and the other, R2, with medium compressive strength of ~40 MPa. The strain was measured in the hoop direction on the inner circumference of the steel ring and on the outer circumference of the concrete ring. Concrete rings were subjected to circumferential drying. Numerical model (ii) predicted critical time to the formation of the first crack to be between 13 and 14 days. The experimentally determined critical time is found to be 11 to 13 days with cracks gradually opening over several days. This was indicated by changes in measured concrete and steel strain. Modelled concrete strain just before cracking was between -20 and -30 % 10-6 m m-1 however, measured concrete strain was ~150 % 10-6 m m-1. Modelled steel strain was between -30 and -40 % 10-6 m m-1 while measured steel strain was between -10 and 20 % 10-6 m m-1. These discrepancies, in particular the positive steel strain obtained in experiments, require further investigation and improvements of the experimental set-up. Ključne besede: concrete, tunnel lining, restrained shrinkage, Reissner beam theory, modelling Objavljeno v DiRROS: 19.01.2024; Ogledov: 354; Prenosov: 141
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1273. The role of thyroid radiation carcinogenesis in ratsKatarina Koritnik, Andrej Cör, 1998, izvirni znanstveni članek Povzetek: The aimof this study was to test the hypothesis on the protective role of thyroxin administration before and during irradiation on the occurrence of thyroid carcinoma in rats. Application of thyroxin before and during irradiation was expected to decrease production of thyrotropin by the hypophyseal feedback mechanism, caused by radiation damage of thyroid tissue. Stabilizing the thyroid cells in this way during irradiation would thus make them less radiosensitive. In the experiment, we first divided 81 three to fourweek old Wistar strain rats of both sexes into two groups, i.e. thyroxin (T4) and water (H2O). The T4 rats were injected 1% thyroxin solution (0.01 mg/100 g body weight) twice a day for 15 days, while the H2O rats received saline in the same way. After ten days, the two main groups were divided each into two subgroups. The rats from both irradiated subgroups (T4/X and (H2O/X) recieved 10 Gy to the neck area. They were iradiated with a telecobalt machinefor five consecutive days with one direct field. During a two years follow - up, all moribund animals were sacrificed and their thyroid glands taken. The rest of the thyroid glands were taken at the end of the experiment.All glands were pathohistologically analysed. Besides, all suspicious and enlarged extrathyroid organs and tissues were examined and the occurrence of tumors was noted. Pathohistological examination revealed the occurrence of 8 thyroid carcinomas and 7 adenomas in the H2O/X group, and 3 adenomas in the T4/X group. In the iradiated group of rats without thyroxin, significantly (P = 0.01) more thyroid carcinomas occurred than in the irradiated group without thyroxin. Objavljeno v DiRROS: 19.01.2024; Ogledov: 272; Prenosov: 63
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1274. Micronuclei in cytokinesis-blocked lymphocytes as an index of occupational exposure to antineoplastic drugsVera Garaj-Vrhovec, Nevenka Kopjar, 1998, izvirni znanstveni članek Povzetek: In order to investigate possible DNA damiging effects of antineoplastic drugs,the micronucleus assay combined with Giemsa, DAPI and silver staining was performed. Blood samples were taken from nurses working without adequate protection in oncological department on preparing and administration of different antineoplastic drugs. Lymphocytes were cultivated in vitro at 37 degrees C. To prevent cytokinesis, at 44th cytochalasine-B at a final concentration of 3 micro g/ml was added. The results obtained indicate statistically significant increases in the total number of micronuclei in the exposed subjects compontrols. DAPI staining has revealed signal-positive and signal-negative miuclei while silver staiing has revealed Ag-NOR+ and Ag-NOR- micronuclei. Compred to controls, the number of signal-positive exposed subjects were increased, indicating a greater susceptibility of particular chromosomes to damage caused by antineopalstic agents. Objavljeno v DiRROS: 19.01.2024; Ogledov: 212; Prenosov: 48
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1275. p53 - the paradigm of tumor-suppresor genes?Barbara Jezeršek Novaković, Srdjan Novaković, 1998, pregledni znanstveni članek Povzetek: p53 is a tumor-suppressor gene the alterations of which are among the most frequent genetic changes detected in human neoplasms. Its product - p53 protein is a component of several biochemical pathways that are central to carcinogenesis: DNA transcription, genomic stability, DNA repair, cell cycle control, and apoptosis. The analysis of the spectrum of p53 mutations and insight into the p53 mediated biochemical pathways of programmed cell death and cell cycle arrest, provide clues to understanding of molecular pathogenesis of cancer of mechanisms related to p53 mediated tumor suppression. The purpose of the resent article is to summarise the most important facts concerning p53 since understanding of the above listed processes might provide the potential molecular targets for the development ofa rational cancer treatment. Objavljeno v DiRROS: 19.01.2024; Ogledov: 253; Prenosov: 74
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1278. Plasma membrane fluidity alterations in cancerous tissuesMarjeta Šentjurc, Mihael Sok, Gregor Serša, 1998, izvirni znanstveni članek Povzetek: Plasma membrane is a heterogeneous structure with several coexisting domains having different fluidity characteristics. It plays an important role in the control of cell growth, differentiation and transformation. Fluidity of the whole plasma membrane reflects the ordering and dynamics of phospholipid acyl chains in specific membrane domains, as well as the fraction of each domain inthe membrane. Changes in the membrane fluidity affect processes on the membrane such as transport, enzyme activities and expression of the redeptors.In this paper we present results of our recent electron paramagneticresonance (EPR) studies of plasma membrane fluidity characteristics, which take into account heterogeneous nature of the plasma membrane, By the computer simulation of the EPR spectra line-shapes, the number of coexisting domains in the plasma membrane, their relative portion inthe membrane as well as the ordering and dynamics of each domain be determined. Therefore, we could distinguish the contribution of the relative portion of each domain from the contribution of fulidity alterations in the domain to the entire fluidity changes in the membrane. Two examples will be discussed: membrane fluidity characteristics of excised lung tumor tissues andinfluence of microtubule depolymerizing agent vinblastine on membrane fluidity of vinblastine sensitive and resistant HeLa cells. Objavljeno v DiRROS: 19.01.2024; Ogledov: 274; Prenosov: 63
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1279. Image cytometry analysis of normal buccal mucosa smears: influence of smoking and sex-related differencesJaka Lavrenčak, Margareta Strojan Fležar, Mario Žganec, Marija Us-Krašovec, 1998, izvirni znanstveni članek Povzetek: To get more information about the influence of smoking on chromatin pattern ofnormal buccal mucosa cells and to assess sex-related differences in nuclear features, quantitative analysis of normal buccal mucosa smears was performed. In this study, buccal smears were collected from 78 healthy subjects. Image cytometry analysis was performed on Feulgen-thionin stained smears. probability distributions of 78 nuclear features were calculated for both, cell-by-cell and slide-by-slide classifications. Seven nuclear features showeddiscriminative ability between smokers and non-smokers; most of them were nuclear texture features. Statistical analysis of nuclear features in groups of females and males hoswed that only two nuclear features were different. It is concluded that smoking should be considered in image cytometry analysis of lesions in oral cavity. Objavljeno v DiRROS: 19.01.2024; Ogledov: 252; Prenosov: 82
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1280. Longitudinal study of malignancy associated changes in progressive cervical dysplasiaMargareta Strojan Fležar, Jaka Lavrenčak, Mario Žganec, Marija Us-Krašovec, 1998, izvirni znanstveni članek Povzetek: Eight of 29 patients with progressive CIN were followed for 2 to 10 years. Their consecutive Pap smears were destained and stained according to Feulgen thionin method. Cyto-Savant/TM high resolution image cytometer (Oncometrics Technol. Corp., Vancouver, Canaderage values of muclear texture features and their probability distributions for consecutive Pap smears from each patient were calculated. Three out of 5 discriminant MAC, highDNAamount, highDNAcomp and highDNAarea, were to increase as a function of time in 5 out of 8 patients. A preliminary analysis which was performed on non-standardized archival material demonstrated a monotonous increase of discrete texture features as a function of time in patients with progressive CIN. Objavljeno v DiRROS: 19.01.2024; Ogledov: 271; Prenosov: 76
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