Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction

The first suggestion that physical exercise results in free radical-mediated damage to tissues appeared in 1978, and the past three decades have resulted in a large growth of knowledge regarding exercise and oxidative stress. Although the sources of oxidant production during exercise continue to be debated, it is now well established that both resting and contracting skeletal muscles produce reactive oxygen species and reactive nitrogen species. Importantly, intense and prolonged exercise can result in oxidative damage to both proteins and lipids in the contracting myocytes. Furthermore, oxidants can modulate a number of cell signaling pathways and regulate the expression of multiple genes in eukaryotic cells. This oxidant-mediated change in gene expression involves changes at transcriptional, mRNA stability, and signal transduction levels. Furthermore, numerous products associated with oxidant-modulated genes have been identified and include antioxidant enzymes, stress proteins, DNA repair proteins, and mitochondrial electron transport proteins. Interestingly, low and physiological levels of reactive oxygen species are required for normal force production in skeletal muscle, but high levels of reactive oxygen species promote contractile dysfunction resulting in muscle weakness and fatigue. Ongoing research continues to probe the mechanisms by which oxidants influence skeletal muscle contractile properties and to explore interventions capable of protecting muscle from oxidant-mediated dysfunction.

/pdf/exercise-induced-oxidative-stress-cellular-mechanisms-and-4a18810890.pdf

Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production

http://www.chcs.org.cn/upload/2014-09/14091721577197.pdf

Incisional ventral hernias: Review of the literature and recommendations regarding the grading and technique of repair

Peritonitis is a common and serious complication of peritoneal dialysis (PD). Although less than 5% of peritonitis episodes result in death, peritonitis is the direct or major contributing cause of death in around 16% of PD patients (1-6). In addition, severe or prolonged peritonitis leads to structural and functional alterations of the peritoneal membrane, eventually leading to membrane failure. Peritonitis is a major cause of PD technique failure and conversion to long-term hemodialysis (1,5,7,8). Recommendations under the auspices of the International Society for Peritoneal Dialysis (ISPD) were first published in 1983 and revised in 1993, 1996, 2000, 2005, and 2010 (9-14). The present recommendations are organized into 5 sections: 1. Peritonitis rate 2. Prevention of peritonitis 3. Initial presentation and management of peritonitis 4. Subsequent management of peritonitis 5.

/pdf/ispd-peritonitis-recommendations-2016-update-on-prevention-28ki6os9ax.pdf

Ispd peritonitis recommendations: 2016 update on prevention and treatment

Background: The pneumoperitoneum is the crucial element in laparoscopic surgery. Different clinical problems are associated with this procedure, which has led to various modifications of the technique. The aim of this guideline is to define the scientifically proven standards of the pneumoperitoneum. Methods: Based on systematic literature searches (Medline, Embase, and Cochrane), an expert panel consensually formulated clinical recommendations, which were graded according to the strength of available literature evidence. Recommendations: Preoperatively, all patients should be assessed for the presence of cardiac, pulmonary, hepatic, renal, or vascular comorbidity. Presupposing appropriate perioperative measures and surgical technique, there is no reason to contraindicate pneumoperitoneum in patients with peritonitis or intraabdominal malignancy. During laparoscopy, monitoring of end tidal CO2 concentration is mandatory. The available data on closed- (Veress needle) and open-access techniques do not allow us to principally favor the use of either technique. Using 2 to 5-mm instead of 5 to 10-mm trocars improves cosmetic result and postoperative pain marginally. It is recommended to use the lowest intraabdominal pressure allowing adequate exposure of the operative field, rather than using a routine pressure. In patients with limited cardiac, pulmonary, or renal function, abdominal wall lifting combined with low-pressure pneumoperitoneum might be an alternative. Abdominal wall lifting devices have no clinically relevant advantages compared to low-pressure (5–7 mmHg) pneumoperitoneum. In patients with cardiopulmonary diseases, intra- and postoperative arterial blood gas monitoring is recommended. The clinical benefits of warmed, humidified insufflation gas are minor and contradictory. Intraoperative sequential intermittent pneumatic compression of the lower extremities is recommended for all prolonged laparoscopic procedures. For the prevention of postoperative pain a wide range of treatment options exists. Although all these options seem to reduce pain, the data currently do not justify a general recommendation.

The European Association for Endoscopic Surgery clinical practice guideline on the pneumoperitoneum for laparoscopic surgery

Uric acid is the final product of purine metabolism in humans. The final two reactions of its production catalyzing the conversion of hypoxanthine to xanthine and the latter to uric acid are catalysed by the enzyme xanthine oxidoreductase, which may attain two inter-convertible forms, namely xanthine dehydrogenase or xanthine oxidase. The latter uses molecular oxygen as electron acceptor and generates superoxide anion and other reactive oxygen products. The role of uric acid in conditions associated with oxidative stress is not entirely clear. Evidence mainly based on epidemiological studies suggests that increased serum levels of uric acid are a risk factor for cardiovascular disease where oxidative stress plays an important pathophysiological role. Also, allopurinol, a xanthine oxidoreductase inhibitor that lowers serum levels of uric acid exerts protective effects in situations associated with oxidative stress (e.g. ischaemia-reperfusion injury, cardiovascular disease). However, there is increasing experimental and clinical evidence showing that uric acid has an important role in vivo as an antioxidant. This review presents the current evidence regarding the antioxidant role of uric acid and suggests that it has an important role as an oxidative stress marker and a potential therapeutic role as an antioxidant. Further well designed clinical studies are needed to clarify the potential use of uric acid (or uric acid precursors) in diseases associated with oxidative stress.

Uric acid and oxidative stress.

Background
The attempt to further reduce operative trauma in laparoscopic cholecystectomy has led to new techniques such as natural orifice transluminal endoscopic surgery (NOTES) and single-incision laparoscopic surgery (SILS) These new techniques are considered to be painless procedures, but no published studies investigate the possibility of different pain scores in these new techniques versus classic laparoscopic cholecystectomy In this randomized control study, we investigated pain scores in SILS cholecystectomy versus classic laparoscopic cholecystectomy

Different pain scores in single transumbilical incision laparoscopic cholecystectomy versus classic laparoscopic cholecystectomy: a randomized controlled trial.

Background: The induction of the pneumoperitoneum increases intraabdominal pressure (IAP), causing splanchnic ischemia, whereas its deflation normalizes IAP and splanchnic blood flow. This procedure appears to represent an ischemia-reperfusion model in humans. Methods: Thirty laparoscopic cholecystectomies (LC) were performed in 30 patients with a mean age of 54.6 ± 15.6 years. A group of 20 patients mean age, 57.3 ± 9.65 who underwent open cholecystectomy (OC) was also studied. Vein plasma levels of thiobarbituric acid-reactive substances (TBARS), a marker of free radical production; plasma total antioxidant status (TAS); and uric acid (UA) levels were measured preoperatively, 5 min after deflation of the pneumoperitoneum or at the end of operation, and 24 h postoperatively. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TBL) levels were measured preoperatively and 24 h after the operation. Results: In the LC group, significant elevations in the concentration of TBARS were observed in the early postoperative measurements in comparison with the preoperative measurements. TAS and UA levels were decreased significantly 24 h postoperatively compared to preoperative levels. The postoperative levels of AST, ALT, and TBL increased significantly in comparison with the preoperative levels. In the OC group, no alterations in the concentration of TBARS were observed in the postoperative period. The other parameters had changes similar to those recorded for the LC group. Conclusions: Free radical-induced lipid peroxidation associated with a decrease in plasma antioxidant capacity and UA levels as well as altered hepatic function is observed after deflation of the pneumoperitoneum. These results suggest that free radicals are generated at the end of a laparoscopic procedure, possibly as a result of an ischemia-reperfusion phenomenon induced by the inflation and deflation of the pneumoperitoneum.

Laparoscopic surgery-induced changes in oxidative stress markers in human plasma

/Summary: Continuous ambulatory peritoneal dialysis catheters can be inserted by open laparotomy as well as by laparoscopy. A prospective randomized study was scheduled to investigate the results'of the laparoscopic versus open laparotomy technique for placement of continuous ambulatory peritoneal dialysis catheters. Fifty patients were enrolled and randomly allocated into two groups of25 patients each. Group A underwent continuous ambulatory peritoneal dialysis catheter placement via the open laparotomy technique. ln22patients, catheters were inserted via midline incision, and in 3 patients with histories of previous catheterization, a paramedian incision was used. Continuous ambulatory peritoneal dialysis was started 24 to 48 hours later. Group B underwent laparoscopic placement of the catheter with fixation into the pelvis and suture closure ofthe port wounds. In 2l patients, this catheter placement was the first such placement, and in 4 patients, a previous catheter had been inserted by the open technique and removed for dysfunction. Continuous ambulatory peritoneal dialysis was started at the end of the procedure. The mean operative time was 22 minutes in group A and 29 minutes in group B (P 0.1). Tip migration occurred in five patients in group A and no patients in group B (P < 0.005). In group B, two patients underwent a simultaneous cholecystectomy and one underwent incisional hernia repair. Laparoscopic placement of a Tenckhoff catheter leads to better function than does the open procedure; it allows immediate start of dialysis without fluid leakage and permits simultaneous performance of other laparoscopic procedures.

Laparoscopic placement of the Tenckhoff catheter for peritoneal dialysis.

After laparoscopic cholecystectomy, CO2 remains within the peritoneal cavity, commonly causing pain. This prospective randomized study was performed to determine the efficacy of intraperitoneal normal saline and bupivacaine infusion on postoperative pain after laparoscopic cholecystectomy. Three hundred patients were randomly assigned to one of six groups of 50 patients each. Group A patients served as controls. In group B patients, normal saline was infused under the right hemidiaphragm and suctioned after the pneumoperitoneum was deflated. After suction, a subhepatic closed drain was left for 24 h. In group C patients, bupivacaine 1.5 mg/kg in solution 2.5 mg/ml, minus 15 ml of this solution, which was infiltrated in the trocar wounds, was infused under the right hemidiaphragm at the end of the cholecystectomy. In group D patients, bupivacaine was given as in group C, but a subhepatic drain was left for 24 h. In group E patients, normal saline was used as in group B plus bupivacaine as in group C. Group F patients were treated as in group E, but a subhepatic drain was left for 24 h. In all groups, 15 ml of a 2.5 mg/ml bupivacaine solution was infiltrated in the trocar wounds. Postoperatively, analgesic medication usage, nausea, vomiting, and pain scores were recorded at 2, 6, 12, 24, 36, 48, and 72 h. Postoperative pain was reduced significantly in the patients of the treatment groups vs. the controls. Between treatment groups, patients in groups B, E, and F had the best results, while those in groups C and D had significantly greater pain than those in groups B, E, and F. It is concluded that postoperative pain after laparoscopic cholecystectomy can be significantly reduced by intraperitoneal normal saline infusion subdiaphragmatically and after its postdeflation suction, bupivacaine infusion in the same area, or without bupivacaine in case a subhepatic drainage has been needed.

Evangelos C. Tsimoyiannis

Papers

Uric acid and oxidative stress.

Different pain scores in single transumbilical incision laparoscopic cholecystectomy versus classic laparoscopic cholecystectomy: a randomized controlled trial.

Laparoscopic surgery-induced changes in oxidative stress markers in human plasma

Laparoscopic placement of the Tenckhoff catheter for peritoneal dialysis.

Intraperitoneal normal saline and bupivacaine infusion for reduction of postoperative pain after laparoscopic cholecystectomy.