Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
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Ferritin L (FTL) and ferritin H (FTH) subunits are responsible for intracellular iron storage. Serum ferritin levels are not only dependant on body iron stores. Aims of the present study are to demonstrate nature, source, and major regulatory mediators of serum ferritin in an animal model of acute-phase (AP) response. ⋯ However, an increase of hepatic FTL but not of FTH protein expression was observed in IL-6ko mice after TO injection. Our data demonstrate that FTL is the only rat serum ferritin whose release into circulation from the hepatocytes is increased by the effect of AP cytokines (e.g., IL-6). In contrast, FTH expression is intracellular in both under physiological and AP conditions.
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Trauma-induced tissue factor (TF) release into the systemic circulation is considered to play an important role in the development of disseminated intravascular coagulation (DIC) immediately after severe trauma. However, the relationship between TF and hyperfibrinolysis, especially fibrinogenolysis, has been unclear. A total of 18 rats were divided into three groups: (a) the control group was infused with normal saline; (b) the low-dose group was infused with 4 U/kg TF; and (c) the high-dose group was infused with 16 U/kg TF. ⋯ The plasmin-α2-plasmin inhibitor complex level in the high-dose group increased more than that of the other groups. In conclusion, TF can induce DIC associated with fibrinolysis and fibrinogenolysis without tissue hypoperfusion. The decrease in the α2-plasmin inhibitor level and the significant increase in the plasmin level may be the two main factors underlying the pathogenesis of hyperfibrin(ogen)olysis after TF administration.
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The acute respiratory distress syndrome (ARDS) is a major public health problem and a leading source of morbidity in intensive care units. Lung tissue in patients with ARDS is characterized by inflammation, with exuberant neutrophil infiltration, activation, and degranulation that is thought to initiate tissue injury through the release of proteases and oxygen radicals. Treatment of ARDS is supportive primarily because the underlying pathophysiology is poorly understood. ⋯ Pharmacological inhibition of broad-spectrum PKC activity and, more importantly, of specific PKC isoforms (as well as deletion of PKCs in mice) exerts protective effects in various experimental models of lung injury. Furthermore, PKC isoforms have been implicated in inflammatory processes that may be involved in the pathophysiologic changes that result in ARDS, including activation of innate immune and endothelial cells, neutrophil trafficking to the lung, regulation of alveolar epithelial barrier functions, and control of neutrophil proinflammatory and prosurvival signaling. This review focuses on the mechanistic involvement of PKC isoforms in the pathogenesis of ARDS and highlights the potential of developing new therapeutic paradigms based on the selective inhibition (or activation) of specific PKC isoforms.