@article{BoeckelKarstenGoepeletal.2023,
  author    = {Boeckel, Hannah and Karsten, Christian M. and G{\"o}pel, Wolfgang and Herting, Egbert and Rupp, Jan and H{\"a}rtel, Christoph and Hartz, Annika},
  title     = {Increased expression of anaphylatoxin C5a-receptor-1 in neutrophils and natural killer cells of preterm infants},
  series = {International Journal of Molecular Sciences},
  volume    = {24},
  journal   = {International Journal of Molecular Sciences},
  number    = {12},
  issn      = {1422-0067},
  doi       = {10.3390/ijms241210321},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-321196},
  year      = {2023},
  abstract  = {Preterm infants are susceptible to infection and their defense against pathogens relies largely on innate immunity. The role of the complement system for the immunological vulnerability of preterm infants is less understood. Anaphylatoxin C5a and its receptors C5aR1 and -2 are known to be involved in sepsis pathogenesis, with C5aR1 mainly exerting pro-inflammatory effects. Our explorative study aimed to determine age-dependent changes in the expression of C5aR1 and C5aR2 in neonatal immune cell subsets. Via flow cytometry, we analyzed the expression pattern of C5a receptors on immune cells isolated from peripheral blood of preterm infants (n = 32) compared to those of their mothers (n = 25). Term infants and healthy adults served as controls. Preterm infants had a higher intracellular expression of C5aR1 on neutrophils than control individuals. We also found a higher expression of C5aR1 on NK cells, particularly on the cytotoxic CD56\(^{dim}\) subset and the CD56\(^-\) subset. Immune phenotyping of other leukocyte subpopulations revealed no gestational-age-related differences for the expression of and C5aR2. Elevated expression of C5aR1 on neutrophils and NK cells in preterm infants may contribute to the phenomenon of "immunoparalysis" caused by complement activation or to sustained hyper-inflammatory states. Further functional analyses are needed to elucidate the underlying mechanisms.},
  language  = {en}
}
@article{DresenLeeHilletal.2023,
  author    = {Dresen, Ellen and Lee, Zheng-Yii and Hill, Aileen and Notz, Quirin and Patel, Jayshil J. and Stoppe, Christian},
  title     = {History of scurvy and use of vitamin C in critical illness: A narrative review},
  series = {Nutrition in Clinical Practice},
  volume    = {38},
  journal   = {Nutrition in Clinical Practice},
  number    = {1},
  doi       = {10.1002/ncp.10914},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318176},
  pages     = {46 -- 54},
  year      = {2023},
  abstract  = {In 1747, an important milestone in the history of clinical research was set, as the Scottish surgeon James Lind conducted the first randomized controlled trial. Lind was interested in scurvy, a severe vitamin C deficiency which caused the death of thousands of British seamen. He found that a dietary intervention with oranges and lemons, which are rich in vitamin C by nature, was effective to recover from scurvy. Because of its antioxidative properties and involvement in many biochemical processes, the essential micronutrient vitamin C plays a key role in the human biology. Moreover, the use of vitamin C in critical illness—a condition also resulting in death of thousands in the 21st century—has gained increasing interest, as it may restore vascular responsiveness to vasoactive agents, ameliorate microcirculatory blood flow, preserve endothelial barriers, augment bacterial defense, and prevent apoptosis. Because of its redox potential and powerful antioxidant capacity, vitamin C represents an inexpensive and safe antioxidant, with the potential to modify the inflammatory cascade and improve clinical outcomes of critically ill patients. This narrative review aims to update and provide an overview on the role of vitamin C in the human biology and in critically ill patients, and to summarize current evidence on the use of vitamin C in diverse populations of critically ill patients, in specific focusing on patients with sepsis and coronavirus disease 2019.},
  language  = {en}
}