| 1. |
- Blessborn, D., et al.
(författare)
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Heat stabilization of blood spot samples for determination of metabolically unstable drug compounds
- 2013
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Ingår i: Bioanalysis. - : Future Science Ltd. - 1757-6180 .- 1757-6199. ; 5:1, s. 31-39
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sample stability is critical for accurate analysis of drug compounds in biosamples. The use of additives to eradicate the enzymatic activity causing loss of these analytes has its limitations. Results: A novel technique for sample stabilization by rapid, high-temperature heating was used. The stability of six commercial drugs in blood and blood spots was investigated under various conditions with or without heat stabilization at 95 degrees C. Oseltamivir, cefotaxime and ribavirin were successfully stabilized by heating whereas significant losses were seen in unheated samples. Amodiaquine was stable with and without heating. Artemether and dihydroartemisinin were found to be very heat sensitive and began to decompose even at 60 degrees C. Conclusion: Heat stabilization is a viable technique to maintain analytes in blood spot samples, without the use of chemical additives, by stopping the enzymatic activity that causes sample degradation.
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| 2. |
- Möller, Per, et al.
(författare)
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Severnaya Zemlya, Arctic Russia: a nucleation area for Kara Sea ice sheets during the Middle to Late Quaternary
- 2006
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 25:21-22, s. 2894-2936
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Tidskriftsartikel (refereegranskat)abstract
- Quaternary glacial stratigraphy and relative sea-level changes reveal at least four expansions of the Kara Sea ice sheet over the Severnaya Zemlya Archipelago at 79 degrees N in the Russian Arctic, as indicated from tills interbedded with marine sediments, exposed in stratigraphic superposition, and from raised-beach sequences that occur at altitudes up to 140 m a.s.l. Chronologic control is provided by AMS C-14, electron-spin resonance, green-stimulated luminescence, and aspartic-acid geochronology. Major glaciations followed by deglaciation and marine inundation occurred during MIS 10-9, MIS 8-7, MIS 6-5e and MIS 5d-3. The MIS 6-5e event, associated with the high marine limit, implies ice-sheet thickness of > 2000m only 200km from the deep Arctic Ocean, consistent with published evidence of ice grounding at similar to 1000m water depth in the central Arctic Ocean. Till fabrics and glacial tectonics record repeated expansions of local ice caps exclusively, suggesting wet-based ice cap advance followed by cold-based regional ice-sheet expansion. Local ice caps over highland sites along the perimeter of the shallow Kara Sea, including the Byrranga Mountains, appear to have repeatedly fostered initiation of a large Kara Sea ice sheet, with exception of the Last Glacial Maximum (MIS 2), when Kara Sea ice did not impact Severnaya Zemlya and barely graced northernmost Taymyr Peninsula.
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| 3. |
- Adamczyk, Barbara, 1985, et al.
(författare)
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Sample handling of gastric tissue and O-glycan alterations in paired gastric cancer and non-tumorigenic tissues
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Sample collection, handling and storage are the most critical steps for ensuring the highest preservation of specimens. Pre-analytical variability can influence the results as protein signatures alter rapidly after tissue excision or during long-term storage. Hence, we evaluated current state-of-the-art biobank preservation methods from a glycomics perspective and analyzed O-glycan alterations occurring in the gastric cancer tissues. Paired tumor and adjacent normal tissue samples were obtained from six patients undergoing gastric cancer surgery. Collected samples (n = 24) were either snap-frozen or heat stabilized and then homogenized. Glycans were released from extracted glycoproteins and analyzed by LC-MS/MS. In total, the relative abundance of 83 O-glycans and 17 derived structural features were used for comparison. There was no statistically significant difference found in variables between snap frozen and heat-stabilized samples, which indicated the two preservation methods were comparable. The data also showed significant changes between normal and cancerous tissue. In addition to a shift from high sialylation in the cancer area towards blood group ABO in the normal area, we also detected that the LacdiNAc epitope (N, N'-diacetyllactosamine) was significantly decreased in cancer samples. The O-glycan alterations that are presented here may provide predictive power for the detection and prognosis of gastric cancer.
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