Perioperative treatment with human growth hormone down-regulates apoptosis and increases superoxide production in PMN from patients undergoing infrarenal abdominal aortic aneurysm repair.

BACKGROUND: Recombinant human growth hormone (hGH) therapy has a beneficial effect on catabolism and wound healing after major surgery. Polymorphonuclear neutrophils (PMN) play an important role in this context. In a prospective, double-blind, randomized, placebo-controlled trial we studied the effect of perioperative hGH treatment on postoperative wound healing and on changes in superoxide generation and susceptibility to apoptosis of PMN in elderly patients undergoing elective abdominal aortic aneurysm repair. METHODS: Seven patients were treated with high-dose hGH (16 U/d) for nine days, seven patients with a placebo. IGF-I, neutrophil count, O2-production induced by opsonized zymosan and apoptosis of PMN were measured and correlated with clinical outcome. RESULTS: Perioperative hGH treatment more than doubled the O2- production in PMN before and 24 h after surgery (p < 0.01). The long-term capacity of PMN to generate O2 in vitro was prolonged (p < 0.001) in the hGH group. Spontaneous and Fas-inducible apoptosis was strongly down-regulated in PMN after surgery in all patients (p < 0.01). hGH-treatment distinctly reduced apoptosis in PMN before and after surgery (p < 0.01). Clinical outcome was similar in both groups. CONCLUSION: Perioperative hGH treatment results in an enhanced O2- production in PMN and in a prolongation of the functional life span of these cells. This may improve immune function and help to overcome the postoperative anergic state of the immune system especially in elderly individuals.

Abdominal surgical interventions: local and systemic consequences for the immune system--a prospective study on elective gastrointestinal surgery.

BACKGROUND: Little is known about the local accumulation and function of immune cells in peritoneal fluid after elective surgery of the upper and lower gastrointestinal tract. Our study was designed to investigate whether systemic immune cell response mirrors the local response. We focused on the cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha and on monocytes, natural killer (NK) cells, and T cells that play an important role in eliciting the innate and adaptive immune response. METHODS: Blood samples were taken prospectively from 25 patients 24 h before surgery, as well as 24 h and 48 h afterward. Abdominal drainage fluids were collected intraoperatively 1 h after the abdomen was opened and 24 h and 48 h postoperatively. Apart from the white blood cells, intracellular T-helper-cell (TH1/TH2) cytokine production (interferon-gamma, IL-2, IL-4, IL-13) and HLA-DR on monocytes were measured by four-color flow cytometry, IL-6, and TNF-alpha with the fast immunoluminescence method. RESULTS: Cells of the innate immune system (NK cells, monocytes, NK-T cells, CD5(+) B cells) rapidly decreased in abdominal fluids (P < 0.05: +24 h; +48 h) after surgery, which was paralleled by a concomitant decline in peripheral blood. The percentage of abdominal interferon-gamma, IL-2, IL-4, and IL-13-producing TH cells increased in a way that distinctly counteracted the decrease of the natural immune cells. HLA-DR expression on monocytes in peripheral blood declined significantly (P < 0.05: +24 h; +48 h). In contrast, monocytes in abdominal fluids had high HLA-DR expression. Furthermore, abdominal fluids contained significantly higher concentrations of TNF-alpha (P < 0.05: +24 h; +48 h) and IL-6 (P < 0.05: +24 h) compared with peripheral blood. CONCLUSIONS: Specific immune cell recruitment and cytokine production play an important role in post-trauma events. Measuring distinct local immune cell repertoires and cytokines provides answers as to how the different phases of postoperative immune events proceed. The evaluation of the local response may provide additional criteria for the evaluation of operative trauma. This knowledge may be helpful in detecting postoperative pathological aberrancies.

L-carnitine ameliorates abnormal vulnerability of steatotic rat livers to cold ischemic preservation.

BACKGROUND: Up to 30% of all livers retrieved for organ transplantation exhibit steatotic transformations. Chronic organ-donor shortage has led to the acceptance of these organs for transplantation, although a higher risk of graft nonfunction is associated with the preservation of steatotic livers. METHODS: A dietary steatosis was induced in Wistar rats by fasting them for 2 days and feeding them with a fat-free diet. Fatty livers (n=14) were retrieved and flushed with 60 mL of histidine, tryptophane, alpha-ketoglutarate (HTK) solution. In half of the experiments, L-carnitine (5 mM) was added to the HTK. Functional integrity of the livers was evaluated by isolated reperfusion with KHB in a recirculating system at 37 degrees C for 45 minutes. RESULTS: Addition of L-carnitine to the HTK promoted a significant reduction of the enzyme leakage from the livers upon reperfusion. Release of alanine-aminotransferase was reduced to one third (127+/-22 vs. 423+/-61 U/L), and the loss of glutamate dehydrogenase in the perfusate could be reduced significantly (42+/-7 vs. 542+/-134 U/L) when compared with livers stored without additional medication. Morphologic corroboration of these data was obtained by electron microscopy. Although normal appearance of liver mitochondria was preserved at the end of the cold ischemic storage, reperfusion of cold-stored fatty livers entailed massive alterations and frequent destruction of hepatic mitochondria. However, these morphologic impairments were remarkably mitigated in the carnitine-treated group. CONCLUSIONS: L-carnitine represents a feasible metabolic adjunct for a safe and more successful preservation of ischemia-reperfusion-sensitive steatotic livers.

Oxygenated machine perfusion mitigates surface antigen expression and improves preservation of predamaged donor livers.

The aim of the present study was to evaluate the potential benefit of machine preservation with the Belzer MPS or HTK solution, compared to standard cold storage, after procurement of marginal livers from non-heart beating donors in an experimental pilot study. Livers from male Wistar rats (250-300 g bw) were harvested after 60 min of cardiac arrest, flushed via the portal vein and cold stored submerged in HTK for 24 h at 4 degrees C while other organs were subjected to oxygenated machine perfusion with HTK or Belzer's MPS at 5 ml/min at 4 degrees C. Cold perfusion of livers with the non-colloidal HTK was not compromised by the lack of oncotic agents and there was no rise in vascular resistance during the 24 h of machine preservation with HTK or the colloidal Belzer MPS. Viability of the livers was assessed after the cold preservation period by warm reperfusion in vitro. Oxygenated machine perfusion was found to significantly increase viability of the livers vs simple cold storage with respect to portal vascular resistance upon reperfusion, enzyme release as well as functional recovery of oxygen utilization or bile production. Moreover, tissue antigen expression of ICAM-1 or histocompatibility antigen class II could be markedly reduced by oxygenated perfusion preservation as compared to cold storage. It is concluded that predamaged organs should preferably be preserved by oxygenated machine perfusion thus minimizing functional alterations and immunogenicity of the graft. In this setup HTK appeared equally effective as Belzer's MPS for machine preservation.

Use of taurine as antioxidant in resuscitating livers from non-heart-beating donors by gaseous oxygen persufflation.

In this study, the importance of antioxidants during oxygenated liver preservation has been investigated. Livers were excised from rats after 60 min of cardiac arrest and stored for 24 h at 4 degrees C in University of Wisconsin solution (UW). Gaseous oxygen was applied to the livers during the storage period via the caval vein after superoxide dismutase (SOD, 600 U/mL), taurine (0.5 mg/mL), or no antioxidant was applied to the graft with the rinse solution. It was shown that oxygen persufflation significantly enhanced the viability of livers during cold preservation only in combination with SOD or taurine, which were both equally effective in reducing lipid peroxidation, enzyme release, and vascular resistance upon postischemic reperfusion. An increase in hepatic bile production was also observed.