1911. Multileaf collimator in radiotherapyMatjaž Jeraj, Vlado Robar, 2004, professional article Abstract: Backgrourcd. Basic goal of radiotherapy treatment is the irradiation of a target valume while minimizing the amount of radiation absorbed in healthy tissue. Shaping the beam is an important way of minimizing the absorbed dose in healthy tissue and critical structures. Conveneional collimator jaws are used for shaping a rectangular treatment field; but, as usually treatment volume is not rectangular, additional shaping is required. On a linear accelerator, lead blocks or individually made CerrobendTM blocks are attached onto the treatment head under standard collimating system. Another option is the use of multileaf collimator (MLC). Conclusions. Multileaf collimator is becoming the main tool for beam shaping on the linear accelerator. It is a simple and useful system in the preparation and performance of radiotherapy treatment. Multileaf eollimators are reliable, as their manufacturers developed various mechanisms for their precision, control and reliability, together with reduction of leakage and transmission of radiation between and through the leaves. Multileaf collimator is known today as a very useful clinical system for simple field shaping, but its use is getting even more important in dynamie radiotherapy, with the leaves rnoving during irradiation.This enables a precise dose delivery on any part of a treated volume. Intensity modulated radiotherapy (IMRT), the therapy of the future, isbased on the dynamic use of MLC. Published in DiRROS: 13.02.2024; Views: 254; Downloads: 59
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1912. Comparison of Wistar vs. Fischer rat in the incidence of 1,2-dimethylhydrazine induced intestinal tumorsŽeljka Večerić-Haler, Anton Cerar, 2004, original scientific article Abstract: Background. Many investigators have observed differences in the susceptibilityto induce intestinal tumors by 1,2-dimethylhydrazine (DMH) between various strains of rodents. The results are difficult to compare because of the different regimes used for induction. The purpose of our study was to evaluate the influence of strain on DMH-induced intestinal tumors between Wistar and Fischer rats. Materials and rreethods. We used 29 Fischer and 30 Wistar male rats that were injected subcutaneously DMH, weekly, at a dosage of 25 mg/kg-body weight for 20 weeks. After 25 weeks from the beginningof the experiment, the animals were sacrificed and autopsied. The complete length of colorectum and all macroscopic changes were examined histologically. Results. The induction of intestinal tumors was 97% in Fischerrats and 100% in Wistar rats. In Wistar rats 184 tumors were found: 133adenomas, 50 tubular adenocarcinomas and 1 signet-cell carcinoma. 77% of careinamas were found in colorectum and 23% in the small intestine. In Fiseherrats, 126 tumors were found: 94 adenomas, 26 tubular adenocarcinomas, 5signet-cell carcinomas and 1 mucinous carcinoma; 42% of carcinomas were foundin the colorectum and 58% in the small intestine. The strain difference in the incidence of all induced tumors was statistically significant (P=0.001). The differences in the occurrence of the malignant and benign tumors was also significant (P<0.001; P=0.011). Extra intestinal tumors were not found. Conclusions. Wistar rats showed greater percentage of colorectal tumors, and also the distribution of tumors in colorectum resembled more the distribution found in human pathology. That is why we reeommend Wistar rat rather than Fischer rat for the research work on the colorectal tumors. Published in DiRROS: 13.02.2024; Views: 273; Downloads: 74
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1913. Sonographically guided fine-needle aspiration biopsies of adrenal masses in lung cancer patients, eleven-year experienceIgor Kocijančič, 2004, original scientific article Abstract: Purpose. The aim of this retrospective study was to define the accuracy and safety of the ultrasonographically (US) guided fine-needle aspiration biopsy (FNAB) of the enlarged adrenals in the patients with lung cancer. Patients andmethods. In eleven-year period 64 patients with cytologically proven lung cancer underwent USguided FNABs of adrenal masses. The accuracy of the method was assessed on the basis of cytology findings and the safety on the number ofcomplications reported after the procedure. Results. US-guided aspiration biopsy turned out to be accurate in 58/64 cases (91%), and very safe with only4/64 (6%) minor complications. In 52/58 (90%) cases, the cytology sample was found to be malignant. In 6 cases (10%), isolated adrenal masses were adenomas. Conclnsions. We recommend US guided FNAB as a safe and reliable diagnostic method that has many advantages over computer tomography (CT) guided FNAB, such as safety, patient friendliness, no X-rays and its reproducibility. Published in DiRROS: 13.02.2024; Views: 285; Downloads: 86
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1914. Poročilo o preskusu št.: LVG 2024-010 : vzorec št. 2024/00044Nikica Ogris, Maarten De Groot, 2024, expertise, arbitration decision Keywords: varstvo gozdov, morfološke analize, graden, Quercus petraea, sušenje, hiranje, kompleksna bolezen Published in DiRROS: 13.02.2024; Views: 360; Downloads: 99
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1916. Cathepsins and their inhibitors as tumor markers in head and neck cancerPrimož Strojan, 2004, review article Abstract: The invasion and metastasizing of tumor cells is closely connected with the disintegration of basement membranes and extracellular matrix. The carriers ofthese processes are different proteolytic enzymes, among them cysteine and aspartic cathepsins B, H, L and D as well, a group of ubiquitous lysosomal proteases, and endogenous inhibitors of the former, cystatins. The aim of the present review was to collect the current knowledge on the predictive and prognostic value of cathepsins and their inhibitors in squamous cell carcinomaof the head and neck. In this particular tumor type, the UICC/AJCC TNM-classification system and histopathological characteristics of the tumors were found inadequate to reliably predict either the response to therapy or patients' survival. Moreover, to date, no factor within the wide spectrum of biochemical and histological factors has yet been idenrified as reliably predicting the natural course of the disease or its response to therapy. To construct a prognostically meaningful tumor profile, new markers are intensively investigated. Published in DiRROS: 13.02.2024; Views: 351; Downloads: 74
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1917. Clinical utility of serine proteases in breast cancerTanja Čufer, 2004, professional article Abstract: The serine protease uPA and its inhibitor PAI-1 are involved in the degradation of tumor stroma and basement membrane. The independent prognostic value of serine protease urokinase-type plasminogen activator uPA and its inhibitor PAI-1 in breast cancer has been almost uniformly confirmed in numerous individual studies as well as in a meta-analysis, including 18 data sets of more than 8,000 patients. According to these observations, the risk ofrelapse in node negative patients with low levels of uPA and PAI-1 is less then 10%; these patients could be spared from toxic adjuvant systemic therapy.Clinically relevant and even more important is the information that uPA and its inhibitor PAI-1 may also have a predictive value for response to either hormonal or cytotoxic therapy in early breast cancer. According to our data obtained from altogether 460 operable breast cancer patients, uPA and PAI-1 may have a predictive value for the response to hormone therapy, but notto chemotherapy. The high PAI-1 levels were associated with a higher risk of relapse in the patients without adjuvant systemic therapy (HR 2.14; C.I. 95%= 0.48-9.56; p=0.321) and in the patients treated with chemotherapy (RR 2.48; C.1. 95%=1.35-4.57; p=0.003). However, in the patients treated with adjuvant hormone therapy, either alone or in combination with chemotherapy, the prognosric value of uPA and PAI-1 was diminished. Moreover, high levels ofboth uPA and PAI-1 were associated with a lower risk of relapse (HR 0.79; p=0.693 and HR 0.26 p= 0.204, respectively). On the basis of currently available evidence, serine protease uPA and its inhibitor PAI-1 are certainly the markers that improve a proper selection of candidates for adjuvant systemic therapy and may also be the markers that could facilitate treatment decision in each individual patient, which is of utmost importance. Published in DiRROS: 13.02.2024; Views: 323; Downloads: 71
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1918. Tumor markers in clinical oncologySrdjan Novaković, 2004, review article Abstract: The subtle differences between normal and tumor cells are exploited in the detection and treatment of cancer. These differences are designated as tumor markers and can be either qualitative or quantitative in their nature. That means that both the structures that are produced by tumor cells as well as thestructures that are produced in excessive amounts by host tissues under theinfluence of tumor cells can function as tumor markers. Speaking in general, the tumor markers are the specific molecules appearing in the blood or tissues and the occurrence of which is associated with cancer. According totheir application, tumor markers can be roughly divided as markers in clinical oncology and markers in pathology. In this review, only tumor markersin clinical oncology are going to be discussed. Current tumor markers in clinical oncology include (i) oncofetal antigens, (ii) placental proteins, (iii) hormones, (iv) enzymes, (v) tumor-associated antigens, (vi) special serum proteins, (vii) catecholamine metabolites, and (viii) miscellaneous markers. As to the literature, an ideal tumor marker should fulfil certain criteria - when using it as a test for detection of cancer disease: (1) posirive results should occur in the early stages of the disease, (2) positiveresults should occur only in the patients with a specific type of malignancy, (3) positive results should occur in all patients with the same malignancy, (4) the measured values should correlate with the stage of the disease, (5) the measured values should correlate to the response to treatment, (6) the marker should be easy to measure. Most tumor markers available today meet several, but not all criteria. As a consequence of that, some criteria were chosen for the validation and proper selection of the most appropriate marker in a particular malignancy, and these are: (1) markers' sensitivity, (2) specificity, and (3) predictive values. (Abstract truncated at 2000 characters). Published in DiRROS: 13.02.2024; Views: 276; Downloads: 63
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1919. Tumor markers in clinical oncologySrdjan Novaković, 2004, review article Abstract: The subtle differences between normal and tumor cells are exploited in the detection and treatment of cancer. These differences are designated as tumor markers and can be either qualitative or quantitative in their nature. That means that both the structures that are produced by tumor cells as well as thestructures that are produced in excessive amounts by host tissues under theinfluence of tumor cells can function as tumor markers. Speaking in general, the tumor markers are the specific molecules appearing in the blood or tissues and the occurrence of which is associated with cancer. According totheir application, tumor markers can be roughly divided as markers in clinical oncology and markers in pathology. In this review, only tumor markersin clinical oncology are going to be discussed. Current tumor markers in clinical oncology include (i) oncofetal antigens, (ii) placental proteins, (iii) hormones, (iv) enzymes, (v) tumor-associated antigens, (vi) special serum proteins, (vii) catecholamine metabolites, and (viii) miscellaneous markers. As to the literature, an ideal tumor marker should fulfil certain criteria - when using it as a test for detection of cancer disease: (1) posirive results should occur in the early stages of the disease, (2) positiveresults should occur only in the patients with a specific type of malignancy, (3) positive results should occur in all patients with the same malignancy, (4) the measured values should correlate with the stage of the disease, (5) the measured values should correlate to the response to treatment, (6) the marker should be easy to measure. Most tumor markers available today meet several, but not all criteria. As a consequence of that, some criteria were chosen for the validation and proper selection of the most appropriate marker in a particular malignancy, and these are: (1) markers' sensitivity, (2) specificity, and (3) predictive values. (Abstract truncated at 2000 characters). Published in DiRROS: 13.02.2024; Views: 290; Downloads: 0 |
1920. SBA-15 mesoporous particles with adsorbed cresol red dye and functionalized with 3-aminopropyl groups : materials properties and dye release studiesErika Švara Fabjan, Romana Cerc Korošec, Klara Šifrer, Andrijana Sever Škapin, Ramon Martinez Manez, 2024, original scientific article Abstract: Research in the field of sensing has focused on tailoring the responsiveness of materials through the variation in materials properties achieved via functionalization of the mesoporous matrix. pH indicator dyes capable of protonation/deprotonation reactions are known to display different forms, resulting in changes in colour. This research focused on the preparation of mesoporous substrates SBA-15 with integrated pH indicator dye o-cresolsulphonephtalein (cresol red) grafted with (3-aminopropy) trimethoxysilane (gaining functionalized-SBA-15 material) in order to gain a colour change response following release of the dye. UV-Vis reflectance and absorbance spectra were used to evaluate forms of cresol red. The textural properties, including specific surface area, pore size distribution and pore volume were evaluated using nitrogen sorption, and XRD analysis was conducted to evaluate crystallinity of the material and pore ordering. The presence of 3-aminopropyl groups was determined by thermal decomposition using TGA–DSC/MS. The functionalized SBA-15 materials loaded with cresol red mostly retained ordering of the pores and showed a slight reduction in surface area. Functionalization changed the surface properties of the material. In the non-functionalized SBA-15, cresol red was present in both double (H2L) and single (HL−) protonated forms, whereas in the functionalized SBA-15 the deprotonated L2−form prevailed. Through desorption experiments cresol red was successfully desorbed from selected sample to different media. The change of colour caused by alterations in the form of the dye once released from the mesoporous silica material into the medium was confirmed. The form of cresol red released was determined by the pH of the medium. Keywords: mezoporozni materiali, SBA-15, funkcionalizacija, uravnavanje odzivnosti, zaznavanje Published in DiRROS: 13.02.2024; Views: 370; Downloads: 252
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