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- Brehmer, Felix, et al.
(författare)
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Interaction of inflammation and hyperoxia in a rat model of neonatal white matter damage.
- 2012
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 7:11
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Tidskriftsartikel (refereegranskat)abstract
- Intrauterine infection and inflammation are major reasons for preterm birth. The switch from placenta-mediated to lung-mediated oxygen supply during birth is associated with a sudden rise of tissue oxygen tension that amounts to relative hyperoxia in preterm infants. Both infection/inflammation and hyperoxia have been shown to be involved in brain injury of preterm infants. Hypothesizing that they might be additive or synergistic, we investigated the influence of a systemic lipopolysaccharide (LPS) application on hyperoxia-induced white matter damage (WMD) in newborn rats. Three-day-old Wistar rat pups received 0.25 mg/kg LPS i.p. and were subjected to 80% oxygen on P6 for 24 h. The extent of WMD was assessed by immunohistochemistry, western blots, and diffusion tensor (DT) magnetic resonance imaging (MRI). In addition, the effects of LPS and hyperoxia were studied in an in vitro co-culture system of primary rat oligodendrocytes and microglia cells. Both noxious stimuli, hyperoxia, and LPS caused hypomyelination as revealed by western blot, immunohistochemistry, and altered WM microstructure on DT-MRI. Even so, cellular changes resulting in hypomyelination seem to be different. While hyperoxia induces cell death, LPS induces oligodendrocyte maturity arrest without cell death as revealed by TUNEL-staining and immunohistological maturation analysis. In the two-hit scenario cell death is reduced compared with hyperoxia treated animals, nevertheless white matter alterations persist. Concordantly with these in vivo findings we demonstrate that LPS pre-incubation reduced premyelinating-oligodendrocyte susceptibility towards hyperoxia in vitro. This protective effect might be caused by upregulation of interleukin-10 and superoxide dismutase expression after LPS stimulation. Reduced expression of transcription factors controlling oligodendrocyte development and maturation further indicates oligodendrocyte maturity arrest. The knowledge about mechanisms that triggered hypomyelination contributes to a better understanding of WMD in premature born infants.
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| 2. |
- Tabernero, Josep, et al.
(författare)
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A Randomized Phase III Study of Arfolitixorin versus Leucovorin with 5-Fluorouracil, Oxaliplatin, and Bevacizumab for First-Line Treatment of Metastatic Colorectal Cancer : The AGENT Trial
- 2024
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Ingår i: Cancer Research Communications. - : American Association For Cancer Research (AACR). - 2767-9764. ; 4:1, s. 28-37
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Tidskriftsartikel (refereegranskat)abstract
- Purpose:Suboptimal treatment outcomes with 5-fluorouracil (5-FU)/folate, the standard of care for metastatic colorectal cancer (mCRC), have generated interest in optimizing the folate. Arfolitixorin ([6R]-5,10-methylene-tetrahydrofolate) is an immediately active folate and may improve outcomes over the existing standard of care (leucovorin).Experimental Design:AGENT was a randomized, phase III study (NCT03750786). Patients with mCRC were randomized to arfolitixorin (120 mg/m2 given as two intravenous bolus doses of 60 mg/m2) or leucovorin (400 mg/m2 given as a single intravenous infusion) plus 5-FU, oxaliplatin, and bevacizumab. Assessments were performed every 8 weeks. The primary endpoint was the superiority of arfolitixorin for overall response rate (ORR).Results:Between February 2019 and April 2021, 490 patients were randomized (245 to each arm). After a median follow-up of 266 days, the primary endpoint of superiority for ORR was not achieved (48.2% for arfolitixorin vs. 49.4% for leucovorin, Psuperiority = 0.57). Outcomes were not achieved for median progression-free survival (PFS; 12.8 and 11.6 months, P = 0.38), median duration of response (12.2 and 12.9 months, P = 0.40), and median overall survival (23.8 and 28.0 months, P = 0.78). The proportion of patients with an adverse event of grade ≥3 severity was similar between arms (68.7% and 67.2%, respectively), as was quality of life. BRAF mutations and MTHFD2 expression were both associated with a lower PFS with arfolitixorin.Conclusions:The study failed to demonstrate clinical benefit of arfolitixorin (120 mg/m2) over leucovorin. However, it provides some useful insights from the first-line treatment setting, including the effect of gene expression on outcomes.Significance:This phase III study compared arfolitixorin, a direct-acting folate, with leucovorin in FOLFOX plus bevacizumab in mCRC. Arfolitixorin (120 mg/m2) did not improve the ORR, potentially indicating a suboptimal dose.
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