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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: 265; Downloads: 83
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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: 189; Downloads: 48
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Abstract: Na sadikah rdečega in črnega bora smo testirali patogenost osmih izbranih izolatov gliv (Corinectria fuckeliana, Diaporthe eres, Diplodia pinea, Fusarium sp. 1 in 2, Fusicolla sp., Nectria dematiosa in Tympanis sp.), ki smo jih izolirali iz obolelih borovih dreves v Sloveniji v letih 2020 in 2021. Inokulirali smo skupno 115 sadik borov (vključno s kontrolo), periodično smo preverjali njihovo zdravstveno stanje in ob prvih znakih sušenja opravili reizolacije iz robov nastalih nekroz. Reizolacije so bile uspešne le v primeru inokulacije z vrstami gliv Diplodia pinea, Diaporthe eres in Fusarium sp. 2. Povprečna dolžina nekroz sadik rdečega bora, inokuliranih z D. pinea, Di. eres in Tympanis sp., se je statistično značilno razlikovala od kontrolnih sadik (p < 0,05). Pri sadikah črnega bora pa so se za statistično značilne izkazale povprečne dolžine nekroz pri kontroli in inokulacijah z glivama D. pinea in Tympanis sp. (p < 0,05).
Keywords: test patogenosti, reizolacije, Pinus sylvestris, rdeči bor, Pinus nigra, črni bor
Published in DiRROS: 25.01.2024; Views: 615; Downloads: 248
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Abstract: Invasive alien species (IAS) adversely impact biodiversity, ecosystem functions and socio-economics. Citizen science can be an effective tool for IAS surveillance, management and research, providing large datasets over wide spatial extents and long time periods, with public participants generating knowledge that supports action. We demonstrate how citizen science has contributed knowledge across the biological invasion process, especially for early detection and distribution mapping. However, we recommend that citizen science could be used more for assessing impacts and evaluating the success of IAS management. Citizen science does have limitations and we explore solutions to two key challenges: ensuring data accuracy and dealing with uneven spatial coverage of potential recorders (which limits the dataset’s ‘fit for purpose’). Greater co-development of citizen science with public stakeholders will help us better realise its potential across the biological invasion process and across ecosystems globally while meeting the needs of participants, local communities, scientists and decision-makers.
Keywords: biosecurity, community science, invasion continuum, invasive alien species, monitoring, volunteers
Published in DiRROS: 25.01.2024; Views: 347; Downloads: 177
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Abstract: Introduction. The basic principles of nuclear medicine imaging instruments aredescribed with the emphasis on multi crystal scintillation and semiconductor gamma cameras, positron emission scanners without detector inter-ring attenuation septa, new detector materials and semiconductor CZT surgical probes for localization of metastases. For the estimation of minimal useful detector diameter the theoretical equation was derived for the 20% lossof absorbed gamma rays at the edge of the detector. Conclusion. Nuclear medicine instrumentation has been passing throgh vigorous development in the last years and will be most likely also in the near future. New detection materials with much better physical characteristics than the standard NaI as regards the stopping power, energy resolutions, fragility, decay time, light output, and density will most likely replace the NaI. It is expected that new imaging devices with several thousands of tiny crystals or semiconductor arrayof small position sensitive areas will improve the sensitivity and specificity of clinical studies. At the same time the small surgical probes made from these materials are also becoming very popular in surgery tracing the regional metastases.
Published in DiRROS: 25.01.2024; Views: 228; Downloads: 48
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