The role of neutrophil gelatinase-associated lipocalin and iron homeostasis in object recognition impairment in aged sepsis-survivor rats.

Older adult patients with sepsis frequently experience cognitive impairment. The roles of brain neutrophil gelatinase-associated lipocalin (NGAL) and iron in older sepsis patients remain unknown. We investigated the effects of lipopolysaccharide-induced sepsis on novel object recognition test, NGAL levels, an inflammatory mediator tumor necrosis factor-α (TNFα) levels, and iron ion levels in the hippocampus and cortex of young and aged rats. The effect of an iron chelator deferoxamine pretreatment on aged sepsis rats was also examined. Young sepsis-survivor rats did not show impaired novel object recognition, TNFα responses, or a Fe2+/Fe3+ imbalance. They showed hippocampal and cortical NGAL level elevations. Aged sepsis-survivor rats displayed a decreased object discrimination index, elevation of NGAL levels and Fe2+/Fe3+ ratio, and no TNFα responses. Pretreatment with deferoxamine prevented the reduction in the object recognition of aged sepsis-survivor rats. The elevation in hippocampal and cortical NGAL levels caused by lipopolysaccharide was not influenced by deferoxamine pretreatment. The lipopolysaccharide-induced Fe2+/Fe3+ ratio elevation was blocked by deferoxamine pretreatment. In conclusion, our findings suggest that iron homeostasis in the cortex and hippocampus contributes to the maintenance of object recognition ability in older sepsis survivors.

Intra-operative intravascular effect of the difference in colloid solutions during acute normovolemic hemodilution.

BACKGROUND: Acute normovolemic hemodilution (ANH) is used to reduce the risk of peri-operative allogeneic blood transfusion. Although crystalloid and/or colloid solutions have been used for volume replacement during ANH, no studies have examined the differences among solutions on the volume status, electrolytes, acid-base balance, and hemodynamic status during surgery with ANH. METHODS: We retrospectively compared the effect of Ringer's lactate with 3% dextran-40 (Saviosol®, DEX group) and 6% hydroxyethyl starch 130/0.4 in 0.9% sodium chloride (Voluven®, HES group) on blood hemoglobin serum electrolytes and estimated blood volume before induction of anesthesia (baseline), after ANH and after blood transfusion following surgery in patients undergoing open gynecological surgery (n = 111 and 67, respectively). The primary outcomes were the changes in hemoglobin and electrolytes after ANH. RESULTS: There were no differences in hemoglobin or electrolytes between the two groups at baseline. Postoperative hemoglobin was significantly higher (11.0 ± 1.5 g/dL vs 9.9 ± 1.3 g/dL) (mean ± SD) in the DEX group than in the HES group (p = 0.03). Postoperative potassium was significantly decreased from the baseline both in the DEX group (137.9 ± 2.5 mmol/L vs 136.3 ± 2.7 mmol/L) and in the HES group (138.3 ± 2.0 mmol/L vs 137.8 ± 2.5 mmol/L) (p < 0.001 for both); however, it was significantly higher than in the DEX group after surgery (p < 0.001). Estimated blood volume after surgery was significantly increased after ANH in both groups; however, it was larger in the HES group than in the DEX group. CONCLUSIONS: Postoperative hemoglobin and potassium were significantly higher, and estimated blood volume was significantly smaller in the DEX than in the HES group.