| 1. |
- Steiner, S., et al.
(författare)
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De novo expression of gastrokines in pancreatic precursor lesions impede the development of pancreatic cancer
- 2022
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Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 41, s. 1507-1517
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Tidskriftsartikel (refereegranskat)abstract
- Molecular events occurring in stepwise progression from pre-malignant lesions (pancreatic intraepithelial neoplasia; PanIN) to the development of pancreatic ductal adenocarcinoma (PDAC) are poorly understood. Thus, characterization of early PanIN lesions may reveal markers that can help in diagnosing PDAC at an early stage and allow understanding the pathology of the disease. We performed the molecular and histological assessment of patient-derived PanINs, tumor tissues and pancreas from mouse models with PDAC (KC mice that harbor K-RAS mutation in pancreatic tissue), where we noted marked upregulation of gastrokine (GKN) proteins. To further understand the role of gastrokine proteins in PDAC development, GKN-deficient KC mice were developed by intercrossing gastrokine-deficient mice with KC mice. Panc-02 (pancreatic cancer cells of mouse origin) were genetically modified to express GKN1 for further in vitro and in vivo analysis. Our results show that gastrokine proteins were absent in healthy pancreas and invasive cancer, while its expression was prominent in low-grade PanINs. We could detect these proteins in pancreatic juice and serum of KC mice. Furthermore, accelerated PanIN and tumor development were noted in gastrokine deficient KC mice. Loss of gastrokine 1 protein delayed apoptosis during carcinogenesis leading to the development of desmoplastic stroma while loss of gastrokine 2 increased the proliferation rate in precursor lesions. In summary, we identified gastrokine proteins in early pancreatic precursor lesions, where gastrokine proteins delay pancreatic carcinogenesis.
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| 2. |
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| 3. |
- Hong, A. C., et al.
(författare)
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Uptake of Hydrogen Peroxide from the Gas Phase to Grain Boundaries: A Source in Snow and Ice
- 2023
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Ingår i: Environmental Science and Technology. - 0013-936X .- 1520-5851. ; 57:31, s. 11626-11633
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Tidskriftsartikel (refereegranskat)abstract
- This work shows that hydrogen peroxidereadily enters grainboundaries in ice and snow directly from the atmosphere. Acceleratedreaction rates in these reservoirs have been described with an impacton air quality and snow composition. Hydrogen peroxide is a primary atmospheric oxidant significantin terminating gas-phase chemistry and sulfate formation in the condensedphase. Laboratory experiments have shown an unexpected oxidation accelerationby hydrogen peroxide in grain boundaries. While grain boundaries arefrequent in natural snow and ice and are known to host impurities,it remains unclear how and to which extent hydrogen peroxide entersthis reservoir. We present the first experimental evidence for thediffusive uptake of hydrogen peroxide into grain boundaries directlyfrom the gas phase. We have machined a novel flow reactor system featuringa drilled ice flow tube that allows us to discern the effect of theice grain boundary content on the uptake. Further, adsorption to theice surface for temperatures from 235 to 258 K was quantified. Disentanglingthe contribution of these two uptake processes shows that the transferof hydrogen peroxide from the atmosphere to snow at temperatures relevantto polar environments is considerably more pronounced than previouslythought. Further, diffusive uptake to grain boundaries appears tobe a novel mechanism for non-acidic trace gases to fill the highlyreactive impurity reservoirs in snow's grain boundaries.
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| 4. |
- Trachsel, Mathias, et al.
(författare)
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Multi-archive summer temperature reconstruction for the European Alps, AD 1053-1996
- 2012
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Ingår i: Quaternary Science Reviews. - : Elsevier. - 0277-3791 .- 1873-457X. ; 46, s. 66-79
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Tidskriftsartikel (refereegranskat)abstract
- We present a multi-archive, multi-proxy summer temperature reconstruction for the European Alpscovering the period AD 1053-1996 using tree-ring and lake sediment data. The new reconstruction isbased on nine different calibration approaches and errors were estimated conservatively. Summertemperatures of the last millennium are characterised by two warm (AD 1053-1171 and 1823-1996) andtwo cold phases (AD 1172-1379 and 1573-1822). Highest pre-industrial summer temperatures of the12th century were 0.3 degC warmer than the 20th century mean but 0.35 degC colder than proxy derivedtemperatures at the end of the 20th century. The lowest temperatures at the end of the 16th centurywere ~1 degC lower than the 20th century mean.
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