1121. Bifocal primary intracranial germinoma in a child. Case reportAleš Koren, 2001, professional article Abstract: Background. Bifocal primary intracranial germinal tumors are rare. Only 5-10% of all germ cell tumors are found both in the suprasellar and pineal region. Case report. In presented patient we found two primary intracranial germinomasin pituitary and pineal gland that were successfully operated. Radiological properties of germinomas and differential diagnosis are discussed. Conclusions. Although the definite histological diagnosis cannot beachieved by computer tomography and/or magnetic resonance images alone, a detailed analysis of neuroradiological images is useful for predicting the histologieal diagnosis.
Published in DiRROS: 25.01.2024; Views: 255; Downloads: 62
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1122. MRI macromolecular contrast agents as indicators of changed tumor blood flowTeodora Ivanuša, Katarina Beravs, Maja Čemažar, Vladimir Jevtič, Franci Demšar, Gregor Serša, 2001, original scientific article Abstract: Background. A rapid mapping technique derived from dynamic contrast enhanced MRI data was used to identify and characterize reduction of blood flow in fibrosarcoma SA-1 tumors treated either by application of electric pulses or vinblastine. Materials and methods. Tissue permeability surface area product (PS) and fractional blood volume (BV) were calculated on a pixel-by-pixel basis using dynamic MRI intensity data after administration of gadomer - 17 orpolylysine-Gd-DTPA; prototypic macromolecular contrast agents designed for blood pool enhancement. PS and BV values of untreated tumors were compared to those of tumors treated by local application of 8 electric pulses (amplitude/distance ratio, 1300 V/cm; duration, 100 us, frequency, 1 Hz) percutaneously to the tumor or by systemic administration of vinblastine (2.5 mg/kg). Results. Both treatments transiently, but significantly reduced tumor blood flow, application of electric pulses to the tumors being by 40% more effective in reducing tumor blood flow than systemic administration of vinblastine. PS and BV values derived with polylysine-Gd-DTPA-enhanced MRI were lower compared to those with gadomer-17, due to larger molecular size. Interestingly, Gd-DTPA-enhanced MRI did not show any significant changes of PSand BV between untreated and treated tumors. Conclusion. This study demonstrates that dynamic contrast enhanced MRI can be effectively used to qualitatively monitor tumor blood flow, and quantitatively by means of BV and PS.
Published in DiRROS: 25.01.2024; Views: 303; Downloads: 69
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1123. Radical irradiation of the prostate. Combination of percutaneous irradiation and irradiation with LDR Ir-192 implantsBorut Kragelj, Franc Guna, Janez Burger, 2001, original scientific article Abstract: Background. The irradiation of the carcinomas of the prostate with the doses above the tolerable ones of standard radiotherapy improves the local control of the disease. The aim of this study is to determine the acute toxicity and tolerability of the high-dose prostate irradiation combining external beam radiotherapy (EBRT) and interstitial low dose rate (LDR) brachyradiotherapy (BRT) Ir-192 of the prostate. Material and methods. We examined medical records of 8 patients with localized carcinoma of the prostate (T2-T3 No-x Mo)treated from August 1999 until February 2000. The initial PSA was 2.7-37.5 ng/ml (median 13.7) and Gleason score 4-9 (median 7). Radiotherapy consisted of 48.6-50.4 Gy of EBRT to the prostate and seminal vesicles (4 patients) or the whole pelvis (4 patients) and 20.0-28.0 Gy of interstital LDR Ir-192 BRT given as a single fraction, fluoroscopic guided transperineal Implantation of the prostate. The cumulative doses of percutaneous and interstitial irraditations to the prostate were 68.6 - 79.1 Gy. Results. Acute toxic effects of irradiation though observed in all patients were of only mild intensity. According to the RTOG criteria, 20/30 toxicities were assessed as grade 1, 9/30 as grade 2, and 1/30 as grade 3. In none of the patients, toxic effects required any specific modification of the treatment regimen. Conclusions. The very first experiences indicate moderate toxicity and optimaltolerance of the treatment by patients. An improvement of implantation techniques may be expected with regular CT controls of the implants and extra attentive care of the implants in the urethra region.
Published in DiRROS: 25.01.2024; Views: 239; Downloads: 86
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1124. What is current practice in soft tissue sarcoma grading?Rastko Golouh, Matej Bračko, 2001, original scientific article Abstract: Purpose. Most published grading systems of soft tissue sarcomas (STS) are somewhat subjective and it seems that there is no definite consensus among experts which of them is the most effective. The aim of this study was to collect data from practicing pathologists and to get some insight in the practice of STS grading. Subjects. A questionnaire was sent to 135 pathologists chosen randomly. Results. There were 88 responders from 30 countries from 5 continents. Most responders (85%) grade STS, more frequently in Europe than in non-European countries. Three-grade system is preferred by both European and non-European pathologists, who use it in almost 77% and 67%,respectively. They apply the criteria set by FNCLCC in 37.3%, by NCI in 24%, by Broders in 12% and by Markhede in 1.4%. In Europe, FNCLCC system is the most widely used. Beside classical histological criteria, other modern methods are applied by more than one half of the responders. Immunohistochemical evaluation of proliferation markers is the method most widely used, followed by molecular markers and DNA flow cytometry. Conclusion.The results of our study indicate that most pathologists consider histologic grade of STS as a valuable, however not completely satisfactory predictor of a patients survival.
Published in DiRROS: 25.01.2024; Views: 291; Downloads: 77
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1125. Computer systems for determination od pressure distribution in the hip joint articular surface : validation and resultsVlado Stankovski, Dragica Smrke, 2001, original scientific article Abstract: Background. In this work, we describe the computer systems Viprecox and ActiveContours that are used in the process of realistic estimation of some biomechanical parameters of the hip joint, including the maximal value of the stress in the hip joint p max. The computer system Active Contours uses standard anteroposterior radiographs of the whole pelvis and both hips for itscalculations and Viprecox in its kernel uses a relatively simple three-dimensional mathematical model of stress distribution in the hip-joint articular surface which has been extensively elsewhere (e.g. Iglič 1996). Material and methods. Both state-of-the-art computer systems were tested by analysing the calculated values of p max for 81 patients (37 males and 44 females). Conclusions. In this way we prove that the described computer systems can be used for the determination of the contact stress distribution from standard AP radiographs.
Published in DiRROS: 25.01.2024; Views: 242; Downloads: 47
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1126. Upgrading of gamma cameras for developing countriesValentin Fidler, Milan Prepadnik, Yanfen Xie, 2001, original scientific article Abstract: Background. The project of upgrading the analog gamma cameras with PC based systems from International Atomic Energy Agency (IAEA) and the Ministry of Science and Technology of RS is presented from the initial basic demands to the final developments. Several national research groups (from China, India, Cuba and Slovenia) were involved in the IAEA development project for the acquisition card with software and the standard set of clinical protocols. Conclusions. The most functionally stable acquisition system tested on severalinternational workshops and in university clinics was the Slovenian onewith a complete set of nuclear medicine clinical protocols, documenting, networking and archiving solutions for simple MS Network or server oriented network systems (NT server, etc). More than 300 gamma cameras in 52 countries all over the world were digitized and put in routine clinical work.
Published in DiRROS: 25.01.2024; Views: 252; Downloads: 47
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1127. First experience with a novel luminescence-based optical sensor for measurement of oxygenation in tumorsTomaž Jarm, Hotimir Lešničar, Gregor Serša, Damijan Miklavčič, 2001, original scientific article Abstract: Background. The purpose of this preliminary study was to evaluate a novel luminescence-based fiber-optic sensor (OxyLite system) for the measurement of partial pressure of oxygen (pO2) in tumors and for the detection of changes inpO2 as a function of time. The new method was used simultaneously with the laser Doppler flowmetry method for the measurement of relative tissue perfusion. Materials and methods. Blood perfusion and pO2 were measured continuously via fiber-optic sensors inserted into SA-1 tumors in anesthetizedAžJ mice. The changes in blood flow and oxygenation of tumors wereinduced by transient changes of the parameters of anesthesia and by injection of a vasoactive drug hydralazine. Results. Both optical methods usedin the study successfully detected the induced changes in blood flow and pO2. The measurements of pO2 were well correlated with measurements of microcirculatory blood perfusion. In the majority of pO2 measurements, we observed an unexpected behavior of the signal during the stabilization processimmediately after the insertion of the probe into tumor. This behaviourof the pO2 signal was most probably caused by local tissue damage induced by the insertion of the probe. Conclusion. The novel luminescence-based optical oximetry can reliably detect local pO2 changes in tumors as a function of time but some aspects of prolonged pO2 measurement by this method require further investigation.
Keywords: sarcoma experimental, blood supply, laser-doppler flowmetry, oxygen, luminiscence
Published in DiRROS: 25.01.2024; Views: 302; Downloads: 97
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1128. Electroporator for in vitro cell permeabilizationMarko Puc, Karel Flisar, Stanislav Reberšek, Damijan Miklavčič, 2001, original scientific article Abstract: The use of high voltage electric pulse technology, electroporation, in cell biology, biotechnology and medicine has attracted an enormous interest. Electroporation is a transient phenomenon that increases the permeability of cell plasma membrane. In the state of high permeability, the plasma membrane allows small and large molecules to be introduced into the cytoplasm, althoughthe cell plasma membrane represents a considerable barrier for them inits normal state. The effectiveness of electroporation depends on many parameters that can be divided into the parameters of the electric field and the parameters that define the state of cells and their surrounding i.e, temperature, osmotic pressure, etc. In this article, we present a prototype electroporator GT-1 for in vitro electropermeabilization that we have developed. Our electroporator offers a vast flexibility of parameters and can generate high and low voltage pulses, of which the latter ones are used for electrophoretic transfer of charged molecules through permeabilized cell plasma membrane.
Keywords: electroporation instrumentation methods, cell membrane permeabilization
Published in DiRROS: 25.01.2024; Views: 346; Downloads: 96
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1129. Combined therapy for oral cavity and oropharyngeal squamous cell carcinoma : depth of invasion as prognostic factorBogdan Čizmarevič, Boštjan Lanišnik, Vojislav Didanovič, Kristina Gornik-Kramberger, 2001, review article Abstract: Background. The aim of the study was to emphasize the importance of surgical management of squamous cell carcinoma (SCC) in the head and neck to find the most important predictive factor for cervical lymph node metastasis and prognostic factor for survival. The use of multimodality therapy is being discussed as well. Patients and methods. From June 1st, 1992 to May 31st, 1998, 154 patients with oral cavity and oropharyngeal SCC were admitted to the Department of Otorhinolaryngology and Cervicofacial Surgery in the Teaching Hospital of Maribor. The criteria for inclusion into the study were met by 142 patients, but only 62/142 patients entered the multimodality protocol (surgery and postoperative radiotherapy). These 62/142 patients were treated surgically and 49 of them were postoperatively irradiated, while 13/62 declined postoperative radiotherapy. Surgical specimen was evaluated for positive or negative lymph nodes, tumor margins and the depth of invasion. Tumor cells were stained for Ki67 proliferative factor. Results. The depth of invasion was the most important predictive factor for the neck metastases in multivariate model including also the grade, pT and T. pN was found to be important in determining the overall survival using Cox regression model (p>0,05). A statistically important discrepancy between N and pN classification was found. In 23 cases N was overrated and in 3 cases underrated. The overall 5-year disease specific survival was 55%. Ki67 correlated with the grade of tumor differentiation. No statistically significant correlation was found with lymph node metastases. Conclusions. The depth of invasion is the most important determining the occurrence of the neck metastases whereas the N status determines the survival.
Published in DiRROS: 25.01.2024; Views: 223; Downloads: 57
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1130. Communication after laryngectomyIrena Hočevar-Boltežar, Miha Žargi, 2001, review article Abstract: Izhodišča. Pri bolnikih z napredovalim rakom grla in spodnjega žrela je kirurška odstranitev grla najbolj primeren način zdravljenja. To zdravljenje pa negativno vpliva na številne pomembne bolnikove funkcije in tudi na govor. Bolniki in metode dela. Po odstranitvi grla je možnih več različnih načinov tvorbe glasu, tako da se vsak laringektomirani bolnik lahko nauči katerega od teh načinov govornega sporazumevanja. Rezultati. Znanih je več različnih, tudielektronskih naprav, ki s pomočjo lastnih baterij proizvajajo zvok. Drugo možnost predstavlja ezofagalni govor, pri katerem se bolnik nauči uporabljati mišični segment na prehodu v zgornji požiralnik kot generator glasu. Kirurško možnost govorne rehabilitacije po laringektomiji pa predstavlja vstavitev proteze v kirurško narejeno fistulo med zgornjim požiralnikom in sapnikom. Proteza usmeri zrak iz pljuč v zgornji požiralnik, glas pa nastane pri prehoduzraka skozi že omenjeni mišični segment. Zaključki. Številni dejavniki vplivajo na izbiro najprimernejšega načina nadomestnega govora pri posameznem bolniku. V Sloveniji največ laringektomiranih bolnikov uporablja ezofagalni govor.
Published in DiRROS: 25.01.2024; Views: 260; Downloads: 74
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