Guglielmo Tellan

NADPH oxidase-mediated platelet isoprostane over-production in cirrhotic patients: implication for platelet activation

In patients with cirrhosis conflicting findings, inherent to platelet function and its clinical implication, are still matters of discussion. Cirrhosis is characterized by enhanced production of isoprostanes, index of oxidative stress in vivo, that is known to stem from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2)‐generating oxidative stress and elicit platelet activation.

Interleukin-10 and apoptotic death of circulating lymphocytes in surgical/anesthesia trauma.

OBJECTIVE To examine the relationship between circulating interleukin-10 (IL-10) and the occurrence of lymphocyte apoptosis after surgical/anesthesia trauma. METHODS Data were collected prospectively on 18 adult patients undergoing elective major surgery. Blood sampling for assessment of lymphocyte apoptosis and IL-10 levels was performed on the day before surgery (t(0)) and at 24 and 96 hours after operation (t(1) and t(2), respectively). After lymphocyte isolation, quantification of apoptosis was made by staining apoptotic cells with 7-amino-actinomycin D. Plasma IL-10 concentrations were measured using enzyme-linked immunosorbent assay. RESULTS A significantly increased frequency of apoptotic CD4(+) and CD8(+) cells (p < 0.05) was observed at t1 measurement (8.10% +/- 0.58% and 12.21% +/- 1.47% for CD4(+) and CD8(+), respectively) compared with preoperative values (1.53% +/- 0.38% and 1.32% +/- 0.45% for CD4(+) and CD8(+), respectively). Plasma IL-10 levels showed a significant elevation at both t(1) and t(2) times, peaking at t(1). At t(1), IL-10 levels were correlated with the frequency of CD4(+) and CD8(+) apoptotic lymphocytes (r = 0.78, p = 0.0005 for IL-10 vs. apoptotic CD4(+); r = 0.71, p = 0.003 for IL-10 vs. apoptotic CD8(+)). CONCLUSION Surgical trauma is associated with a significant but transient increase in lymphocyte commitment to apoptosis and IL-10 production. The exact relationship linking the overproduction of IL-10 with lymphocyte apoptosis after a surgical operation is still elusive and requires further investigation.

SERUM NEOPTERIN AND SOLUBLE INTERLEUKIN-2 RECEPTOR FOR PREDICTION OF A SHOCK STATE IN GRAM-NEGATIVE SEPSIS

PURPOSE This study aimed to investigate the predictive value of neopterin and soluble interleukin-2 (IL-2) receptor for shock occurrence in gram-negative sepsis. METHODS We examined 57 patients admitted to an intensive care unit with gram-negative sepsis diagnosed according to preestablished criteria. Blood samples were collected every 24 hours and neopterin and soluble IL-2 receptor were measured by using commercially available test kits. To judge the predictive significance of these analyses the Cox proportional hazards regression model was used. RESULTS Both neopterin (P < .05) and soluble IL-2 receptor (P < .01) were identified as significant predictors of a shock state, but the prognostic strength of neopterin exceeded that of soluble IL-2 receptor. To further assess if other factors could interfere with the predictive significance of both compounds, we also investigated other clinical and laboratory variables but these candidate predictors did not contribute any additional significant predictive information. CONCLUSION The measurement of serum neopterin and soluble IL-2 receptor concentrations has predictability for identifying patients with gram-negative sepsis at risk for progression toward the syndrome of septic shock.

Increased HMGB1 expression and release by mononuclear cells following surgical/anesthesia trauma

IntroductionHigh mobility group box 1 (HMGB1) is a key mediator of inflammation that is actively secreted by macrophages and/or passively released from damaged cells. The proinflammatory role of HMGB1 has been demonstrated in both animal models and humans, since the severity of inflammatory response is strictly related to serum HMGB1 levels in patients suffering from traumatic insult, including operative trauma. This study was undertaken to investigate HMGB1 production kinetics in patients undergoing major elective surgery and to address how circulating mononuclear cells are implicated in this setting. Moreover, we explored the possible relationship between HMGB1 and the proinflammatory cytokine interleukin-6 (IL-6).MethodsForty-seven subjects, American Society of Anesthesiologists physical status I and II, scheduled for major abdominal procedures, were enrolled. After intravenous medication with midazolam (0.025 mg/Kg), all patients received a standard general anesthesia protocol, by thiopentone sodium (5 mg/Kg) and fentanyl (1.4 μg/Kg), plus injected Vecuronium (0.08 mg/Kg). Venous peripheral blood was drawn from patients at three different times, t0: before surgery, t1: immediately after surgical procedure; t2: at 24 hours following intervention. Monocytes were purified by incubation with anti-CD14-coated microbeads, followed by sorting with a magnetic device. Cellular localization of HMGB1 was investigated by flow cytometry assay; HMGB1 release in the serum by Western blot. Serum samples were tested for IL-6 levels by ELISA. A one-way repeated-measures analysis ANOVA was performed to assess differences in HMGB1 concentration over time, in monocytes and serum.ResultsWe show that: a) cellular expression of HMGB1 in monocytes at t1 was significantly higher as compared to t0; b) at t2, a significant increase of HMGB1 levels was found in the sera of patients. Such an increase was concomitant to a significant down-regulation of cellular HMGB1, suggesting that the release of HMGB1 might partially derive from mononuclear cells; c) treatment of monocytes with HMGB1 induced in vitro the release of IL-6; d) at t2, high amounts of circulating IL-6 were detected as compared to t0.ConclusionsThis study demonstrates for the first time that surgical/anesthesia trauma is able to induce an early intracellular upregulation of HMGB1 in monocytes of surgical patients, suggesting that HMGB1 derives, at least partially, from monocytes.

Effect of l-carnitine on oxidative stress and platelet activation after major surgery

Background: The surgical/anesthesia trauma is associated with an increased production of reactive oxygen species (ROS). This enhanced oxidative stress leads to cell damage resulting in various complications such as sepsis, myocardial injury and increased mortality. The aim of this study was to investigate the role of antioxidant treatment with l‐carnitine in oxidative stress and platelet activation in patients undergoing major abdominal surgery.

Plasma levels of IL-10 and nitric oxide under two different anaesthesia regimens.

Background and objective: An alteration in production of both interleukin‐10 (IL‐10) and nitric oxide (NO) has been found following surgical/anaesthesia trauma. It is also suggested that IL‐10 could be an important factor in regulating NO metabolism during the postoperative period. Furthermore, NO seems to play a crucial role in the anaesthetic state. The purpose of this study was to investigate plasma levels of IL‐10 and NO following surgery, any possible correlation between these two variables and whether anaesthesia technique could influence NO and IL‐10 circulating concentrations. Methods: Thirty‐two patients scheduled to undergo elective major surgery were enrolled in the study and allocated into two groups to receive two different techniques of anaesthesia, total intravenous (i.v.) anaesthesia (Group I) and inhalational anaesthesia (Group II). Blood samples were drawn before (t0), at the end (t1) of operation and after 24 h (t2). Plasma IL‐10 and NO levels were measured by using an enzyme‐linked‐immunosorbent assay (ELISA) and a total NO assay kit, respectively. Results: In both patient groups there was a significant decrease of plasma NO levels at the end of surgery (30.35 ± 2.70 mmol L−1 at t0 to 13.76 ± 1.51 mmol L−1 at t1 in Group I, P < 0.0001; 28.23 ± 2.50 mmol L−1 at t0 to 11.38 ± 0.95 mmol L−1 at t1 in Group II, P < 0.0001). This reduction remained at 24 h postoperatively (14.33 ± 1.52 mmol L−1 in Group I, P < 0.0001; 12.52 ± 1.11 mmol L−1 in Group II, P < 0.0001, both vs. t0). There was an increase in IL‐10 concentrations (26.35 ± 3.42 pg mL−1 and 75.39 ± 8.33 pg mL−1 at t1 and t2, respectively, vs. 4.93 ± 0.31 pg mL−1 at t0, P = 0.03 and P < 0.0001, respectively, in Group I; 26.18 ± 3.22 pg mL−1 and 69.91 ± 7.33 pg mL−1 at t1 and t2, respectively, vs. 5.50 ± 0.33 pg mL−1 at t0, P = 0.02 and P < 0.0001, respectively, in Group II). No relationship was found between circulating IL‐10 and NO. Conclusions: During the postoperative period, IL‐10 overproduction does not correlate with the decrease in systemic NO concentration.

Pancuronium bromide, a non-depolarizing muscle relaxant which promotes apoptosis of blood lymphocytes in vitro.

Background:  Several compounds used in anesthesia practice have demonstrated to impair immune function and to influence the process of apoptotic death in T cell population following surgical trauma. We designed this study to test in vitro the impact of neuromuscular blocker, such as pancuronium, at clinically relevant concentration on lymphocyte apoptosis, death factor expression and mitochondrial function.

Expression of receptors tyrosine kinase c-kit and EGF-R in colorectal adenocarcinomas: is there a relationship with epithelial-mesenchymal transition during tumor progression?

To the Editor:We read with great interest the contribution by Friederichsand colleagues regarding immunohistochemical detectionof the receptor tyrosine kinases c-kit, EGF-R, and PDGF-Rin colorectal adenocarcinomas [1]. The authors showedEGF-R expression in only 15.3% of cases; emphasized thatactivity of tyrosine kinase inhibitors does not necessarilycorrelate with the tyrosine kinase expression of the tumors;showed that there is no correlation between EGF-R incolorectal cancer, clinical response to anti-EGF-R anti-bodies, and outcome; and that pretreatment selection ofpatients cannot be based on immunohistochemical expres-sion of EGF-R.EGF has recently been identified as a novel inducer ofepithelial–mesenchymal transition (EMT) in human breastcancer [2]. EMT is a process of plasticity by whichepithelial cells lose contact with adjacent cells andbasement membranes, switch patterns of extracellularmatrix protein and intermediate filament expression, andtransdifferentiate into mesenchymal cells. EMT duringtumor progression allows tumor cells to infiltrate surround-ing tissue and to metastatize to distant sites. A key event inEMT is reduction of cell–cell adhesion by transcriptionalrepression of E-cadherin. Loss of E-cadherin expression hasbeen reported in several cancers, including advancedcolorectal carcinomas. EMT hallmarks include reductionof E-cadherin with concomitant production of N-cadherinand acquisition of mesenchymal markers such as vimentinand fibronectin [3, 4]. EMT may influence the response ofcertain tumors to EGF-R-targeted therapies. In nonsmallcell lung cancer cell lines, sensitivity to an EGF-R-targetedmonoclonal antibody (erlotinib) did not correlate with EGF-R levels, but was dependent on EMT status: non-responding nonsmall cell lung carcinomas showed lowlevels of E-cadherin and higher levels of mesenchymalmarkers [5, 6].In the study by Friederichs et al., positive EGF-Rstaining did not show significant correlation with patho-logical parameters, but higher expression of EGF-R inadvanced and metastatic stages in colorectal adenocarcino-mas was reported in other studies.Friederichs et al. concluded that c-kit expression is rarein colorectal carcinomas, and because of the small numberof cases, it is uncertain if c-kit-positive carcinomasrepresent a specific entity or in which way these carcinomasdiffer. The authors suggested that in colorectal cancerwithout c-kit kinase activation, treatment with recentlydeveloped and less selective tyrosine kinase inhibitors mayresult in inhibition of alternative or related tyrosine kinase

Circulating Leptin, Ghrelin, Glucose, Insulin, C-Peptide, GH, IGF-1, Cortisol,and Interleukin-6 Concentrations, and the Systemic Stress Responseto Uncomplicated Surgical Injury

The mechanisms initiating, regulating and sustaining the systemic stress response to a surgical injury have not all been identified yet. Recent studies point to the adipose tissue as a major endocrine system, the hormones of which in- fluence energy homeostasis, glucose and lipid metabolism, vascular homeostasis, and immune response. Essential ele- ments of this control system are leptin and ghrelin. The purpose of the present study was to compare the patterns of leptin and ghrelin secretion in different perioperative periods in patients undergoing elective cholecystectomy, and to relate the changes in circulating leptin or ghrelin to concomitantly occurring changes in glucose, insulin, C-peptide, growth hor- mone (GH), insulin-like growth factor (IGF)-1, total cortisol, free cortisol index, and interleukin-6, and other clinical pa- rameters. Thirty patients were included in the study. Blood was sampled at seven time points between one hour prior to the induction of anesthesia (first observation) to approximately 24 hours later. Both leptin and ghrelin displayed a parallel decrease in concentrations from baseline in the intra-and postoperative periods, with a parallel return to baseline on the morning of the first postoperative day. However, at each perioperative period the leptin trend was not associated with that of other substances(including ghrelin).Likewise, the ghrelin time trend was independent of other study variables (includ- ing leptin). What triggers this response remains unknown but this study implies that it is unlikely to be the hypothalamic- pituitary-adrenocortical, GH/IGF-1, or glucose homeostatic axis, or proinflammatory cytokines.