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Povzetek: Glioblastoma (GB) is the most common primary malignant brain tumor, characterized by resistance to therapy. Despite aggressive treatment options, GB remains an incurable disease. Invasiveness and heterogeneity are key GB features that cannot be studied in preclinical in vitro models. In this study, we investigated the effects of standard therapy using patient-derived GB organoids (GBOs). GBOs reflect the complexity and heterogeneity of the original tumor tissue. No significant effect on GBO viability or invasion was observed after irradiation and temozolomide treatment. E3 ubiquitin-protein ligase (MDM2), cyclin-dependent kinase inhibitor 1A (CDKN1A), and the serine/threonine kinases ATM and ATR were upregulated at the gene and protein levels after treatment. Our results show that the p53 pathway and DNA-damage response mechanisms were triggered, suggesting that GBOs recapitulate GB therapy resistance. GBOs thus provide a highly efficient platform to assess the specific responses of GB patients to therapy and to further explore therapy resistance.
Ključne besede: cellular physiology, cellular toxicology, in vitro toxicology including 3D culture, technical aspects of cell biology, cancer
Objavljeno v DiRROS: 09.09.2024; Ogledov: 0; Prenosov: 2
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Objavljeno v DiRROS: 09.09.2024; Ogledov: 12; Prenosov: 8
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Povzetek: Wood is considered a promising raw material for the circular bioeconomy and has the ability to store biogenic carbon, and this is one reason why we want to extend the service life of the wood. In order to consider the influence of durability in our study, we used two wood species with different lifespans. Beech (Fagus sylvatica L.) belongs to the group of very sensitive wood species, as the durability of the untreated wood is estimated to be around 5 years; meanwhile, pine (Pinus sylvestris L.) belongs to the group of moderately resistant wood species, where the durability of the untreated wood is estimated to be up to 15 years. While toxic chemicals are often used for wood preservation, hydroxyapatite offers an environmentally friendly solution for wood mineralization. This study presents life cycle assessment (LCA) and life cycle cost (LCC) analyses comparing a novel hydroxyapatite (HAp) mineralization method with a service life of 50 years to a non-mineralized reference alternative. LCA was based on EN ISO 14040 and EN ISO 14044, while LCC was adapted from the European Commission’s LCC tool for public procurement. The results of the LCA show that mineralized wood has a lower overall impact on the environment than surface-treated beech wood but a higher impact than surface-treated pine wood. Most impact categories were determined by electricity consumption with the exception of stratospheric ozone depletion, water consumption, and land use. Water consumption proved to be the category where the mineralization process was problematic due to water consumption during the leaching process. The LCC showed that mineralized wood is the most cost-effective solution for the exterior façade, as all costs, but especially investment costs, were lower. The differences in the LCA and LCC results are mainly due to the different lifetimes of the two alternatives. It can be concluded that if energy-intensive processes and chemicals are used in the production of the material, the extended lifetime must be sufficient to account for the additional impacts that occur during the production phase.
Ključne besede: environmental impacts, hydroxyapatite, life cycle assessment (LCA), life cycle cost analysis (LCC), wood mineralization
Objavljeno v DiRROS: 09.09.2024; Ogledov: 14; Prenosov: 5
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Ključne besede: varstvo gozdov, morfološke analize
Objavljeno v DiRROS: 06.09.2024; Ogledov: 53; Prenosov: 0
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Povzetek: Due to the stratospheric ozone depletion, several organisms will become exposed to increased biologically active UVB (280-320 nm) radiation, not only at polar but also at temperate and tropical latitudes. Bloom forming cyanobacteria are exposed to UVB radiation on a mass scale, particularly during the surface bloom and scum formation that can persist for long periods of time. All buoyant species of cyanobacteria are at least periodically exposed to higher irradiation during their vertical migration to the surface that usually occurs several times a day. The aim of this study is to assess the influence on cyanobacteria of UVB radiation at realistic environmental intensities. The effects of two UVB intensities of 0.5 and 0.99 W/m2 in up to 0.5 cm water depth were studied in vitro on Microcystis aeruginosa strains, two microcystin producing and one non-producing. After UVB exposure their ability to proliferate was estimated by cell counting, while cell fitness and integrity were evaluated using light microscopy, autofluorescence and immunofluorescence. Gene damage was assessed by TUNEL assay and SYBR Green staining of the nucleoide area. We conclude that UVB exposure causes damage tothe genetic material, cytoskeletal elements, higher sedimentation rates and consequent cell death. In contrast to microcystin producers (PCC7806 and FACHB905), the microcystin non-producing strain PCC7005 is more susceptible tothe deleterious effects of radiation, with weak recovery ability. The ecological relevance of the results is discussed using data from eleven yearsʼcontinuous UVB radiation measurements within the area of Ljubljana city (Slovenia, Central Europe). Our results suggest that increased solar radiationin temperate latitudes can have its strongest effect during cyanobacterial bloom formation in spring and early summer. UVB radiation in this period may significantly influence strain composition of cyanobacterial blooms in favor of microcystin producers.
Ključne besede: microcystin, cyanobacteria
Objavljeno v DiRROS: 06.09.2024; Ogledov: 51; Prenosov: 24
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