Effect of major liver resection on hepatic ureagenesis in humans

Changes in hepatic ureagenesis following major hepatectomy are not well characterized. We studied the relation between urea synthesis and liver mass before and after major hepatectomy in humans. Fifteen patients scheduled for resection of malignancies in otherwise healthy livers were studied. Pre- and postoperative liver volume was assessed by computerized tomography-volumetry. During surgery, a primed, continuous infusion of [(13)C]urea was administered intravenously, and arterial blood samples were obtained hourly. Indocyanine green clearance was determined before and after resection. Seven patients underwent major hepatectomy, and eight patients underwent minor [<5% functional liver volume (total volume -- tumor volume)] or no resection, serving as controls. Resected functional liver volume in the major hepatectomy group averaged 60%. Urea synthesis per gram of functional liver tissue increased 2.6-fold following major hepatectomy, maintaining whole body urea synthesis. Arterial ammonia remained unchanged throughout the study, whereas following hepatectomy a hyperaminoacidemia occurred. In conclusion, immediately following major hepatectomy, urea synthesis per gram of functional liver tissue increases rapidly and proportionately to the amount of liver tissue resected, maintaining whole body urea synthesis at preoperative levels. This rapid and complete adaptation suggests that the capacity of urea synthesis is not limiting the maximum resectable volume in otherwise healthy livers.

Laparoscopic sleeve resection of a recurrent gastric cascade: a case report

The cascade stomach consists of a biloculation of the gastric cavity into a ventral (corpus and antrum) and a dorsal (fundus) recess and is a rare cause of upper abdominal symptoms. The causes of gastric cascade described in the literature are manifold and are separated into congenital, functional, or organic disorders. Patients with a gastric cascade can have a range of upper abdominal symptoms, including nausea, vomiting, dyspepsia, eructation, heartburn, epigastric pain, and early satiety. This disorder is often difficult to diagnose or is not recognized and, therefore, its true incidence is currently not known. As a consequence, data on the treatment of the condition are limited. Suggested treatment options in the literature range from conservative measures, such as bending exercises or dietary adjustments, to operative corrections, such as gastropexy and laparoscopic gastro-gastric anastomosis. In this paper, we summarize the literature findings on gastric cascade and report on a new treatment option: the laparoscopic gastric sleeve resection.

The significance of bowel permeability

PURPOSE OF REVIEW

In clinical research, increased permeability has been scrutinized as a potential indicator of the severity of gastrointestinal disease and as a potential cause of the perpetuation of severe inflammatory activity in infectious states. This review discusses old and recent epidemiological and clinical evidence to establish whether increased permeability in sepsis is a sequel or a cause of multiple organ failure. In addition, old and new evidence linking inflammation and permeability in abnormal gastrointestinal anatomy and function to liver abnormalities in susceptible patients will be reviewed.

RECENT FINDINGS

Intestinal permeability has been found to be increased in several gastrointestinal diseases but not to be a very good marker of the severity of disease. Evidence is put forward supporting the claim that increased intestinal permeability is part of generalized leakiness of tight junctions in multiple organ failure and to play a less strong role as a primary event in its pathogenesis. Endemic malnutrition has been shown to be caused by interplay between malnutrition and intestinal inflammation. Recently experimental evidence has been put forward suggesting that enteral fat has anti-inflammatory effects on the intestine via the autonomic nervous system. Old clinical and new epidemiological evidence links intestinal inflammation, disruption of the enterohepatic cycle of bile acids, and liver disease.

SUMMARY

The implications of the described findings are that inflammatory activity, locally induced by abnormal intestinal anatomy and disruption of the bile acid pool, or systemically by severe and uncontrolled inflammation/infection, should be the focus of treatment or research. In addition, the connection between intestinal inflammation and liver disease should be investigated.

Effect of high-fat enteral nutrition on hepatocyte injury in response to hemorrhagic shock in the rat

BACKGROUND

High-fat enteral nutrition reduces the inflammatory response following hemorrhagic shock in the rat.

AIMS

We hypothesized that this intervention might also ameliorate the remote organ injury to the liver associated with this model.

METHODS

Male Sprague-Dawley rats were either starved or fed low-fat or high-fat isocaloric isonitrogenous feed prior to nonlethal hemorrhagic shock induced by a 40% reduction in the blood volume. Animals were sacrificed at 90 minutes or 24 hours after injury. Liver cell damage was assessed by histology and long polymerase chain reaction (PCR) to detect mitochondrial DNA damage. Stress protein expression was measured by Western blot and mRNA expression by real-time PCR and immunohistochemistry.

RESULTS

Animals fed a low-fat diet had the same severity of liver injury as starved animals and increased expression of stress proteins. Animals fed a high-fat diet had minimal liver injury, no evidence of mitochondrial DNA damage, and significantly lower expression of stress proteins. This effect is associated with preservation of hepatocellular morphology, attenuation of mitochondrial DNA damage, and a reduced stress protein response to injury.

CONCLUSIONS

High-fat enteral nutrition protects the liver from the remote effects of hemorrhagic shock, but the mechanism of this effect is not yet known.

Endothelial activation markers and their key regulators after restrictive bariatric surgery

OBJECTIVE

Increased plasma levels of endothelial activation markers in obese subjects reflect the positive association between cardiovascular diseases and obesity. The pro-inflammatory state associated with obesity is thought to play a major role in endothelial cell activation in severely obese individuals. Previous studies demonstrated that long-term weight loss after bariatric surgery is accompanied by a decreased proinflammatory state. However, little is known about the long-term effects of bariatric surgery on endothelial cell activation.

RESEARCH METHODS AND PROCEDURES

Plasma levels of soluble intercellular adhesion molecule-1 (sICAM-1), soluble endothelial selectin (sE-selectin), and soluble vascular cell adhesion molecule-1 (sVCAM-1), all markers of endothelial cell activation, and of their regulators adiponectin and resistin were measured at different time-points postoperatively in 26 consecutive patients who underwent restrictive surgery, with a follow-up of 2 years.

RESULTS

During the first 6 months after bariatric surgery, sE-selectin levels decreased. Despite substantial weight loss, sICAM-1 and sVCAM-1 plasma levels did not decrease significantly. After 24 months, sICAM-1 levels were significantly decreased, whereas sE-selectin levels were further decreased. However, sVCAM-1 levels remained elevated. Adiponectin levels did not change significantly during the first 6 months after bariatric surgery, whereas resistin levels increased. After 24 months, adiponectin levels were similar to normal-weight controls, but resistin levels remained high.

DISCUSSION

Reductions in plasma levels of different markers of endothelial activation after bariatric surgery show different temporal patterns, suggesting that distinct mechanisms are involved in their regulation. Although not all endothelial activation markers normalize after bariatric surgery, our findings suggest that bariatric surgery can reduce endothelial activation in the long term.

[Gastric reduction in morbidly obese adults in the Netherlands]

Obesity results in several health problems, the most important of these being diabetes mellitus type 2. In patients with morbid obesity (BMI > or = 35 kg/m(2) and comorbidity or BMI > or = 40 kg/m(2)) in particular, prevention or treatment of health problems resulting from the obesity is only possible with considerable and lasting weight loss. Gastric reduction surgery with the adjustable gastric band has been shown to be safe and effective. This is also true for the more invasive techniques such as the gastric bypass and the biliopancreatic diversion. Surgical treatment is the only treatment that can induce substantial and lasting weight loss (> 50% of the excess weight, on average) in this patient group in the long run. Although the availability of surgical treatment is as yet inadequate in the Netherlands, it has recently improved considerably. Reimbursement of the treatment is however still an obscure issue and the reimbursement of the follow-up is uncertain. Possibly, the current experiments with independent treatment centers will be able to put an end to this uncertainty.

Conversion of vertical banded gastroplasty to Roux-en-Y gastric bypass results in restoration of the positive effect on weight loss and co-morbidities: evaluation of 101 patients

BACKGROUND

Vertical banded gastroplasty (VBG) is a widely used restrictive procedure in bariatric surgery. However, the re-operation rate after this operation is high. In the case of VBG failure, a conversion to Roux-en-Y gastric bypass (RYGBP) is an option. A study was undertaken to evaluate the results of the conversion from VBG to RYGBP.

METHODS

101 patients had conversion from VBG to RYGBP. Patients were separated into 3 groups, based on the indication for conversion: weight regain (group 1), excessive weight loss (group 2) and severe eating difficulties (group 3). Data for the study were collected by retrospective analysis of prospectively recorded data.

RESULTS

Weight regain (group 1) was the reason for conversion in 73.3% of patients. Staple-line disruption was the most important cause for the weight regain (74.3%). Excessive weight loss (group 2) affected 14% of patients and was caused by outlet stenosis in 78.6% of patients. The remaining 13% had severe eating difficulties as a result of outlet stenosis (46.1%), pouch dilatation (30.8%) and pouch diverticula (23.1%). Mean BMI before conversion to RYGBP was 40.5, 22.3 and 29.8 kg/m2 in group 1, 2 and 3, respectively. Minor or major direct postoperative complications were observed in 2.0% to 7.0%. Long-term complications were more frequent, and consisted mainly of anastomotic stenosis (22.7%) and incisional hernia (16.8%). Follow-up after conversion was achieved in all patients (100%), with a mean period of 38 +/- 29 months. BMI decreased from 40.5 to 30.1 kg/m2, increased from 22.3 to 25.3 kg/m2. and decreased slightly from 29.8 to 29.0 kg/m2 in group 1, 2 and 3, respectively. All patients in group 3 noticed an improvement in eating difficulties.

CONCLUSION

Complications after conversion from failed VBG to RYGBP are substantial and need to be considered. However, the conversion itself is a successful operation in terms of effect on body weight and treating eating difficulties after VBG.

Exposure to bacterial DNA before hemorrhagic shock strongly aggravates systemic inflammation and gut barrier loss via an IFN-gamma-dependent route

OBJECTIVE

To investigate the role of bacterial DNA in development of an excessive inflammatory response and loss of gut barrier loss following systemic hypotension.

SUMMARY BACKGROUND DATA

Bacterial infection may contribute to development of inflammatory complications following major surgery; however, the pathogenesis is not clear. A common denominator of bacterial infection is bacterial DNA characterized by unmethylated CpG motifs. Recently, it has been shown that bacterial DNA or synthetic oligodeoxynucleotides containing unmethylated CpG motifs (CpG-ODN) are immunostimulatory leading to release of inflammatory mediators.

METHODS

Rats were exposed to CpG-ODN prior to a nonlethal hemorrhagic shock. The role of interferon-gamma (IFN-gamma) was investigated by administration of anti IFN-gamma antibodies.

RESULTS

Exposure to CpG-ODN prior to hemorrhagic shock significantly augmented shock-induced release of IFN-gamma, tumor necrosis factor-alpha (TNF-alpha) (P < 0.05), interleukin (IL)-6 (P < 0.05), and nitrite levels (P < 0.05), while there was a defective IL-10 response (P < 0.05). Simultaneously, expression of Toll-like receptor (TLR) 4 in the liver was markedly enhanced. Furthermore, intestinal permeability for HRP significantly increased and bacterial translocation was enhanced in hemorrhagic shock rats pretreated with CpG-ODN. Interestingly, inhibition of IFN-gamma in CpG-treated animals reduced TNF-alpha (P < 0.05), IL-6 (P < 0.05), nitrite (P < 0.05), and intestinal permeability following hemorrhagic shock (P < 0.05) and down-regulated expression of TLR4.

CONCLUSION

Exposure to bacterial DNA strongly aggravates the inflammatory response, disrupts the intestinal barrier, and up-regulates TLR4 expression in the liver following hemorrhagic shock. These effects are mediated via an IFN-gamma-dependent route. In the clinical setting, bacterial DNA may be important in development of inflammatory complications in surgical patients with bacterial infection.

Inter-disciplinary European guidelines on surgery of severe obesity

In 2005, for the first time in European history, an extraordinary Expert panel named 'The BSCG' (Bariatric Scientific Collaborative Group), was appointed through joint effort of the major European Scientific Societies which are active in the field of obesity management. Societies that constituted this panel were: IFSO - International Federation for the Surgery of Obesity, IFSO-EC - International Federation for the Surgery of Obesity - European Chapter, EASO - European Association for Study of Obesity, ECOG - European Childhood Obesity Group, together with the IOTF (International Obesity Task Force) which was represented during the completion process by its representative. The BSCG was composed not only of the top officers representing the respective Scientific Societies (four acting presidents, two past presidents, one honorary president, two executive directors), but was balanced with the presence of many other key opinion leaders in the field of obesity. The BSCG composition allowed the coverage of key disciplines in comprehensive obesity management, as well as reflecting European geographical and ethnic diversity. This joint BSCG expert panel convened several meetings which were entirely focused on guidelines creation, during the past two years. There was a specific effort to develop clinical guidelines, which will reflect current knowledge, expertise and evidence based data on morbid obesity treatment.

Robot-assisted Versus Conventional Laparoscopic Nissen Fundoplication

BACKGROUND

Laparoscopic Nissen fundoplication offers clear benefits for our patients, but requires advanced laparoscopic skills. Robotic assistance in laparoscopic antireflux surgery improves dexterity skills and shortens learning curve, possibly leading to faster, more precise, and safer laparoscopic surgery.

METHODS

We review our first 11 cases of robot-assisted laparoscopic Nissen fundoplication using the 4-armed daVinci surgical system, comparing them with patients who underwent conventional laparoscopic Nissen fundoplication for gastroesophageal reflux disease in the same period.

RESULTS

Robot-assisted laparoscopic Nissen fundoplication did not result in more complications. However, the use of robotic assistance took an extra-47 minutes to complete the operation and costs were raised with an accessory euro 987.47.

CONCLUSIONS

The use of robotic assistance in laparoscopic antireflux surgery is safe and feasible, but results in longer operating time and higher costs compared with conventional laparoscopic surgery without proven benefit at this moment.

Re-operation after laparoscopic adjustable gastric banding leads to a further decrease in BMI and obesity-related co-morbidities: results in 33 patients

BACKGROUND

Laparoscopic adjustable gastric banding (LAGB) is a safe technique with few direct postoperative complications. However, long-term complications such as slippage and pouch dilatation are a well-known problem and re-operations are necessary in a substantial number of patients. In this study, the results of laparoscopic re-operations after LAGB are evaluated.

METHODS

33 patients had a re-operation because of failed LAGB. 29 patients had major re-operation and 4 patients minor re-operation under local anesthesia. The charts of these patients were retrospectively studied.

RESULTS

Mean time between the first band placement and re-operation was 28.1 +/- 17.6 months. The cause of band dysfunction was anterior slippage (n=17), band erosion (n=5), band intolerance (n=3), posterior slippage (n=2) and band leakage (n=2). Symptoms of band dysfunction were vomiting (n=16), pyrosis (n=13), nausea (n=8), retrosternal pain (n=11) and regurgitation (n=5). Laparoscopic refixation of the band was performed in 19 patients: the band was replaced in 4 patients while in 1 patient the band was removed; in 3 patients, the laparoscopic procedure was converted to open surgery; 5 patients underwent conversion to a bypass procedure (biliopancreatic diversion in 3 and gastric bypass in 2). There were no direct postoperative complications except for wound infections (n=2). Postoperative follow-up was 100% with a mean period of 34 +/- 19 months. BMI decreased further from 37.5 +/- 6.4 kg/m(2) before re-operation to 33 +/- 7 kg/m(2). Obesity-related co-morbidity also decreased further or completely dissolved. 3 patients (9%) again developed anterior slippage and a second laparoscopic re-operation was necessary.

CONCLUSIONS

A laparoscopic re-operation for band-related complications after LAGB is safe and feasible. With band slippage, a laparoscopic refixation was possible in 89%. Re-operation leads to further decrease in BMI and obesity-related co-morbidities.

Low number of omental preadipocytes with high leptin and low adiponectin secretion is associated with high fasting plasma glucose levels in obese subjects

OBJECTIVE

This study investigates whether fasting plasma glucose (FPG) levels in obese subjects are associated with the number of preadipocytes and their adipokine-secretion capabilities.

DESIGN

Abdominal subcutaneous and omental adipose tissues were obtained from 10 female and four male obese subjects (age 37 +/- 8 years; BMI 48 +/- 13 kgm(2)) with a wide range of FPG (range: 4.3-10.6 mm). Stromal vascular cells (SVC) were isolated and cultured and the number of attached SVC (aSVC) per gram adipose tissue determined. The aSVCs were differentiated in vitro to become adipocytes, and the secretion of the adipokine leptin and adiponectin in the culture media was determined. Spearman rank correlation coefficients were calculated between FPG and preadipocyte number and adipokine secretion.

PATIENTS

Subject-inclusion criteria: BMI >40 kg/m(2) and for severe comorbid conditions BMI >35 kg/m(2). Subject-exclusion criteria: severe cardiopulmonary pathology (ASA class 3), history of bariatric surgery, manifest psychopathology, 18 years < age > 60 years and for upper-abdominal surgery, age >50 years. All females in the study had regular menstrual periods. None of participants received glucose-lowering medication.

RESULTS

No association was observed between BMI and fasting glucose levels. More than 90 +/- 20% of the cultured aSVC fraction was able to store fat droplets, indicating the presence of preadipocytes. A strong negative association was observed between omental preadipocyte number and FPG. A strong association was observed between adipokine secretion by the omental preadipocytes and FPG. No association was observed between subcutaneous preadipocyte number and adipokine secretion and FPG.

CONCLUSIONS

In morbid obese subjects, low number of omental preadipocytes with high-leptin- and low-adiponectin-secretion profiles is associated with high FPG.

Advantages of advanced laparoscopic systems

BACKGROUND

Conventional laparoscopy offers great benefits to our patients, but suffers from major technical drawbacks. Advanced laparoscopic systems are being developed addressing some of these drawbacks.

METHODS

We performed a training-box based study, performing laparoscopic tasks using conventional laparoscopy and advanced laparoscopic systems in order to assess the influence of these technical drawbacks in order to predict where the biggest advantages of newly developed surgical systems can be expected.

RESULTS

The most significant technical drawbacks were two-dimensional vision, disturbed eye-hand target axis and (possibly to a lesser extent) the rigid instruments with a limited five degrees of freedom.

CONCLUSION

Major advances in advanced laparoscopy might only be expected using console-based robot-arm manipulated systems like the daVinci surgical system, or a combination of a high-quality 3-dimensional vision system, restoration of the eye-hand-target axis and the use of an advanced handheld instrument offering seven degrees of freedom such as the Radius surgical system.

First results after introduction of the four-armed da Vinci Surgical System in fully robotic laparoscopic cholecystectomy

BACKGROUND

Laparoscopic cholecystectomy offers less post-operative pain, less complications, and faster recovery compared with open cholecystectomy. However, laparoscopic surgery can be demanding because of several technical drawbacks. Robotic surgery allows dexterity skills to be performed faster and shortens the learning curve, possibly leading to faster and safer laparoscopic surgery.

METHODS

In this paper, we report the results of our first 12 cases of fully robotic laparoscopic cholecystectomy using the da Vinci Surgical System, comparing them with 12 cases of conventional laparoscopic cholecystectomy. Using a fourth arm in robotic laparoscopy enables the surgeon to perform surgery without the use of a tableside assistant, leading to non-tiring, tremble-free assistance and reducing salary costs. Primary end points are operating time and costs. Secondary end points are operative complications and duration of admission.

RESULTS

Fully robotic cholecystectomy was completed in all 12 cases without increased complication rate and without conversions. However, robotic assistance results in an increased overall operating room stay of 31 min and increased costs of EUR 1,180.62.

CONCLUSION

Fully robotic laparoscopic cholecystectomy is safe and feasible but seems more expensive and time consuming at this moment.

Laparoscopic adjustable gastric banding versus open vertical banded gastroplasty: a prospective randomized trial

BACKGROUND

Laparoscopic adjustable gastric banding (LAGB) and open vertical banded gastroplasty (VBG) are treatment modalities for morbid obesity. However, few prospective randomized clinical trials (RCT) have been performed to compare both operations.

METHODS

100 patients (50 per group) were included in the study. Postoperative outcomes included hospital length of stay (LOS), complications, percent excess weight loss (%EWL), BMI and reduction in total comorbidities. Follow-up in all patients was 2 years.

RESULTS

LOS was significantly shorter in the LAGB group. 3 LAGB were converted to open (1 to gastric bypass). Directly after VBG, 3 patients needed relaparotomies due to leakage, of which one (2%) died. After 2 years, 100% follow-up was achieved. BMI and %EWL were significantly decreased in both groups but significantly more in the VBG group compared to the LAGB group (31.0 kg/m2 and 70.1% vs 34.6 and 54.9% respectively). Co-morbidities significantly decreased in both groups in time. 2 years after LAGB, 20 patients needed reoperation for pouch dilation/slippage (n=12), band leakage (n=2), band erosion (n=2) and access-port problems (n=4). In the VBG group, 18 patients needed revisional surgery due to staple-line disruption (n=15), narrow outlet (n=2) or insufficient weight loss (n=1). Furthermore, 8 VBG patients developed an incisional hernia.

CONCLUSION

This RCT demonstrates that, despite the initial better weight loss in the VBG group, based on complication rates and clinical outcome, LAGB is preferred. It had a shorter LOS and less postoperative morbidity.

Monitoring global volume-related hemodynamic or regional variables after initial resuscitation: What is a better predictor of outcome in critically ill septic patients?

OBJECTIVE

Regional variables of organ dysfunction are thought to be better monitoring variables than global pressure-related hemodynamic variables. Whether a difference exists between regional and global volume-related variables in critically ill patients after resuscitation is unknown.

DESIGN

Prospective diagnostic test evaluation.

SETTING

University-affiliated mixed intensive care unit.

PATIENTS

Twenty-eight critically ill patients.

INTERVENTIONS

Using standardized resuscitation, hemodynamic optimization was targeted at mean arterial pressure, heart rate, occlusion pressure, cardiac output, systemic vascular resistance, and urine output. Primary outcome variable was in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

During resuscitation, global volume-related hemodynamic variables were measured simultaneously and compared with regional variables. At admission no variable was superior as a predictor of outcome. During resuscitation, significant changes were seen in mean arterial pressure, central venous pressure, oxygen delivery, systemic vascular resistance, total blood volume, right heart and ventricle end-diastolic volume, right ventricle ejection fraction, right and left stroke work index, intramucosal carbon dioxide pressure, gastric mucosal pH, mucosal-end tidal Pco2 gap, indocyanine green blood clearance, indocyanine green plasma clearance, and plasma disappearance rate. Multivariate analysis identified lactate, gastric mucosal pH, mucosal-end tidal Pco2 gap, mucosal-arterial Pco2 gap, indocyanine green plasma clearance, and plasma disappearance rate of dye as nondependent predictors of outcome. Patients who subsequently died had a significantly lower gastric mucosal pH, higher intramucosal carbon dioxide pressure and mucosal-end tidal Pco2 gap, and lower indocyanine green blood clearance, indocyanine green plasma clearance, plasma disappearance rate, and right ventricular end-diastolic volume index, of which gastric mucosal pH, mucosal-end tidal Pco2 gap, and indocyanine green blood clearance were the most important predictors of outcome.

CONCLUSIONS

Initial resuscitation of critically ill patients with shock does not require monitoring of regional variables. After stabilization, however, regional variables are the best predictors of outcome.

Meta-analysis of hemodynamic optimization: relationship to methodological quality

Introduction

To review systematically the effect of interventions aimed at hemodynamic optimization and to relate this to the quality of individual published trials.

Methods

A systematic, computerized bibliographic search of published studies and citation reviews of relevant studies was performed. All randomized clinical trials in which adult patients were included in a trial deliberately aiming at an optimized or maximized hemodynamic condition of the patients (with oxygen delivery, cardiac index, oxygen consumption, mixed venous oxygen saturation and/or stroke volume as end-points) were selected. A total of 30 studies were selected for independent review. Two reviewers extracted data on population, intervention, outcome and methodological quality. Agreement between reviewers was high: differences were eventually resolved by third-party decision. The methodological quality of the studies was moderate (mean 9.0, SD 1.7), and the outcomes of the randomized clinical trials were not related to their quality.

Results

Efforts to achieve an optimized hemodynamic condition resulted in a decreased mortality rate (relative risk ratio (RR) 0.75 (95% confidence interval (CI) 0.62 to 0.90) in all studies combined. This was due to a significantly decreased mortality in peri-operative intervention studies (RR 0.66 (95% CI 0.54 to 0.81). Overall, patients with sepsis and overt organ failure do not benefit from this method (RR 0.92 (95% CI 0.75 to 1.11)).

Conclusion

This systematic review showed that interventions aimed at hemodynamic optimization reduced mortality. In particular, trials including peri-operative interventions aimed at the hemodynamic optimization of high-risk surgical patients reduce mortality. Overall, this effect was not related to the trial quality.

Nutritional stimulation of cholecystokinin receptors inhibits inflammation via the vagus nerve

The immune system in vertebrates senses exogenous and endogenous danger signals by way of complex cellular and humoral processes, and responds with an inflammatory reaction to combat putative attacks. A strong protective immunity is imperative to prevent invasion of pathogens; however, equivalent responses to commensal flora and dietary components in the intestine have to be avoided. The autonomic nervous system plays an important role in sensing luminal contents in the gut by way of hard-wired connections and chemical messengers, such as cholecystokinin (CCK). Here, we report that ingestion of dietary fat stimulates CCK receptors, and leads to attenuation of the inflammatory response by way of the efferent vagus nerve and nicotinic receptors. Vagotomy and administration of antagonists for CCK and nicotinic receptors significantly blunted the inhibitory effect of high-fat enteral nutrition on hemorrhagic shock-induced tumor necrosis factor-α and interleukin-6 release (P < 0.05). Furthermore, the protective effect of high-fat enteral nutrition on inflammation-induced intestinal permeability was abrogated by vagotomy and administration of antagonists for CCK and nicotinic receptors. These data reveal a novel neuroimmunologic pathway, controlled by nutrition, that may help to explain the intestinal hyporesponsiveness to dietary antigens, and shed new light on the functionality of nutrition.

Strain-specific effects of probiotics on gut barrier integrity following hemorrhagic shock

Probiotic therapy modulates the composition of the intestinal flora and inhibits the inflammatory response. These properties may be of benefit in the preservation of gut barrier integrity after injury or stress. In this study, we examined the effect of two Lactobacillus strains selected for their pathogen exclusion properties on intestinal barrier integrity following hemorrhagic shock. Additionally, the responsiveness of the macrophage cell line RAW 264.7 to combined exposure to Lactobacillus DNA or oligodeoxynucleotides containing CpG motifs (CpG-ODN) and endotoxin was assessed by measuring tumor necrosis factor alpha (TNF-alpha) release. Rats were administered lactobacilli (5 x 10(9) CFU) or vehicle for 7 days and were subjected subsequently to hemorrhagic shock by withdrawal of 2.1 ml blood/100 g tissue. Levels of plasma endotoxin, bacterial translocation to distant organs, and filamentous actin (F-actin) in the ileum were determined 24 h later. Rats treated with Lactobacillus rhamnosus showed reduced levels of plasma endotoxin (8 +/- 2 pg/ml versus 24 +/- 4 pg/ml; P = 0.01), bacterial translocation (2 CFU/gram versus 369 CFU/gram; P < 0.01), and disruption of F-actin distribution following hemorrhagic shock compared with nontreated control rats. In contrast, pretreatment with Lactobacillus fermentum had no substantial effect on gut barrier integrity. Interestingly, DNA preparations from both lactobacilli reduced endotoxin-induced TNF-alpha release dose dependently, whereas CpG-ODN increased TNF-alpha release. In conclusion, the pathogen exclusion properties of both Lactobacillus strains and the reduction of endotoxin-induced inflammation by their DNA in vitro are not prerequisites for a beneficial effect of probiotic therapy on gut barrier function following hemorrhagic shock. Although pretreatment with Lactobacillus spp. may be useful to preserve gut barrier integrity following severe hypotension, a thorough assessment of specific strains seems to be essential.

Combination of laparoscopic adjustable gastric banding and gastric bypass: current situation and future prospects -- routine use not advised

Although bariatric surgery has proven to be the most effective treatment for morbid obesity, most surgical techniques do have failures. In an effort to improve the reliability, several surgeons started to use a combination of a laparoscopic gastric bypass with an adjustable gastric band. Because of concerns regarding a possible negative outcome, an expert meeting was organized to evaluate the current situation and future application. In total, 104 operations were reported,with several technical variations. The overall complication rate was acceptable, but the percentage of the band erosions was 6.7%, which is too high. The potential advantages (adjustability, maintained access to the stomach and biliary tree, and reversibility) do not compensate for this complication rate. Based on the results and the opinion of the surgeons experienced in this technique, it is concluded that the combination of gastric bypass with an adjustable gastric band to form the pouch is not recommended.

High-fat enteral nutrition reduces endotoxin, tumor necrosis factor-alpha and gut permeability in bile duct-ligated rats subjected to hemorrhagic shock

BACKGROUND/AIMS

Cholestatic patients are prone to septic complications after major surgery due to an increased susceptibility to endotoxin and hypotension. High-fat enteral nutrition reduces endotoxin after hemorrhagic shock. However, it is unknown whether this nutritional intervention is protective in biliary obstruction. We investigated the effect of high-fat enteral nutrition on endotoxin, tumor necrosis factor-alpha (TNF-alpha) and intestinal permeability in cholestatic rats subjected to hemorrhagic shock.

METHODS

Bile duct-ligated (BDL) rats were fasted or fed with low-fat or high-fat enteral nutrition before hemorrhagic shock. Blood and tissue samples were taken after 90 min.

RESULTS

Plasma endotoxin decreased after hemorrhagic shock in BDL-rats fed with high-fat nutrition compared to fasted (P<0.01) and low-fat treated rats (P<0.05). Additionally, circulating TNF-alpha was reduced in BDL-rats pretreated with high-fat nutrition compared to fasted rats (P<0.01). The increased intestinal permeability to macromolecules was reduced by high-fat enteral nutrition, whereas bacterial translocation did not significantly change. Simultaneously, tight junction distribution in ileum and colon was disrupted in non-treated BDL-rats but remained unchanged in high-fat pretreated BDL-rats.

CONCLUSIONS

High-fat enteral nutrition protects against endotoxin-mediated complications independently of intraluminal bile. These results provide a potential new strategy to prevent endotoxin-mediated complications in cholestatic patients undergoing major surgery.

Preadipocyte number in omental and subcutaneous adipose tissue of obese individuals

OBJECTIVE

To determine the variation in preadipocyte isolation procedure and to assess the number and function of preadipocytes from subcutaneous and omental adipose tissue of obese individuals.

RESEARCH METHODS AND PROCEDURES

The preadipocyte number per gram of adipose tissue in the abdominal-subcutaneous and abdominal-omental adipose stores of 27 obese subjects with a BMI of 44 +/- 10 kg/m(2) and an age of 40 +/- 9 years was determined.

RESULTS

The assessment of the preadipocyte number was found to be labor intensive and error prone. Our data indicated that the number of stromal vascular cells (SVCs), isolated from the adipose tissue by collagenase digestion, was dependent on the duration of collagenase treatment and the size and the origin of the biopsy. In addition, the fat accumulation and leptin production by differentiated SVCs were dependent on the number of adherent SVCs (aSVCs) in the culture plate and the presence of proteins derived from serum and peroxisome proliferator-activated receptor ligands.

DISCUSSION

Using our standardized isolation and differentiation protocol, we found that the number of SVCs, aSVCs, leptin production, and fat accumulation still varied considerably among individuals. Interestingly, within individuals, the number of SVCs, aSVCs, and the leptin production by differentiating aSVCs from both the subcutaneous and the omental fat depots were associated, whereas fat accumulation was not. In obese to severely obese subjects, differences in BMI and age could not explain differences in SVCs, aSVCs, leptin production, and fat accumulation.

Ghrelin, Leptin and Insulin Levels after Restrictive Surgery: a 2-Year Follow-up Study

BACKGROUND

Ghrelin is a recently discovered orexigenic gastric hormone, whose production is induced by lack of food in the stomach. In morbidly obese individuals, ghrelin levels are low compared to lean persons. During dieting, plasma ghrelin levels increase, leading to an orexigenic signal, which could explain the lack of success of dieting in morbidly obese individuals. Morbid obesity is best treated with bariatric surgery, in which gastric bypass is reported to be more effective than restrictive surgery. A possible explanation could be the difference in plasma ghrelin levels after both operations for bariatric surgery. In this study, plasma ghrelin levels were investigated during a 2-year follow-up.

METHODS

17 morbidly obese patients received gastric restrictive surgery. Plasma ghrelin, leptin and insulin levels were evaluated preoperatively and 1 year and 2 years postoperatively.

RESULTS

BMI decreased from 47.5 +/- 6.2 kg/m(2) to 33.2 +/- 5.8 kg/m(2) (P <0.001). Plasma ghrelin levels were significantly increased 1 year (P <0.05) and 2 years (P <0.02) postoperatively. Fasting plasma leptin and insulin levels were significantly lower at 2 years after surgery (P <0.001).

CONCLUSION

After gastric restrictive surgery, ghrelin levels increased, in contrast to the reported fall in ghrelin levels after gastric bypass. This difference in ghrelin levels between these operations may be the key to understanding the superiority of gastric bypass in sustaining weight loss compared with restrictive surgery.

Leptin in Morbidly Obese Patients: No Role for Treatment of Morbid Obesity but Important in the Postoperative Immune Response

Despite the current opinion that leptin can no longer be seen as a hormone which could be used therapeutically to prevent an energy surplus (it rather protects the organism for an energy deficit), leptin may still have an impact in clinical medicine. Leptin was shown to have several important functions. The pleiotropic properties of leptin include a regulatory function in the immune system. Reviewing the effects of leptin on different parts of the immune system reveals that the immune system is deregulated in an environment low in leptin. A strong reduction in leptin levels occurs in situations of starvation as seen after bariatric surgery. We postulate the hypothesis that the starvation-induced postoperative decrease of leptin is causative of the more serious course of complications observed after bariatric surgery.

Gastric myoelectrical activity in morbidly obese patients before and 3 months after gastric restrictive surgery

BACKGROUND

Morbid obesity is often associated with gastrointestinal motor disorders. The aim of this study was to investigate gastric motility in morbid obesity, using electrogastrography (EGG) before and 3 months after gastric restrictive surgery.

METHODS

40 morbidly obese subjects (age 40.6+/-10.3 years, BMI 46.4+/-5.7 kg/m2) were studied. VBG and Lap-Band operations were performed in 19 and 21 patients respectively. The following EGG-parameters were determined, both during fasting (f) and postprandially (pp): dominant frequency (DF(f/pp)), dominant power (DP(f/pp)), dominant frequency and power instability coefficient (DFIC and DPIC respectively) and power ratio.

RESULTS

In the Lap-Band group, DF(pp), DP(pp) and DFIC(pp) were significantly higher compared with the preprandial state, both preoperatively and 3 months postoperatively. After VBG, DF(f) and DFIC(pp) were significantly lower and DPIC(f) significantly higher compared with the preoperative state. Furthermore, DF(pp) and DP(pp) were significantly higher than the preprandial values. However, in both types of operations, power ratio did not differ significantly between the preoperative and postoperative situation. Furthermore, no clear difference in EGG-parameters between both operations could be observed.

CONCLUSION

After gastric restrictive surgery, no major changes in gastric myoelectrical activity occurred, suggesting that if clinical motility problems occur after bariatric surgery, they are not due to gastric myoelectrical dysfunction.

Enteral administration of high-fat nutrition before and directly after hemorrhagic shock reduces endotoxemia and bacterial translocation

OBJECTIVE

To determine whether potential enhancement of endotoxin neutralization via high-fat enteral nutrition affects endotoxemia and bacterial translocation after hemorrhage.

SUMMARY BACKGROUND DATA

Endotoxin and bacterial translocation due to gut barrier failure are important initiating events in the pathogenesis of sepsis after hemorrhage. Systemic inhibition of endotoxin activity attenuates bacterial translocation and distant organ damage. Triacylglycerol-rich lipoproteins constitute a physiological means of binding and neutralizing endotoxin effectively. We hypothesized that enhancement of triacylglycerol-rich lipoproteins via high-fat enteral nutrition would reduce endotoxemia and prevent bacterial translocation.

METHODS

A rat model of nonlethal hemorrhagic shock was used. Hemorrhagic shock (HS) rats were divided into 3 groups: rats starved overnight (HS-S); rats fed with a low-fat enteral diet (HS-LF), and rats receiving a high-fat enteral diet (HS-HF).

RESULTS

Circulating triacylglycerol and apolipoprotein B, reflecting the amount of triacylglycerol-rich lipoproteins, were elevated in HS-HF rats compared with both HS-S rats (P

CONCLUSION

This study is the first to show that high-fat enteral nutrition, leading to increased plasma triacylglycerol and apolipoprotein B levels, significantly decreases endotoxemia and bacterial translocation after hemorrhage.

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MESH Headings

• Animals
• Apolipoproteins B/blood
• Bacterial Translocation
• Dietary Fats/administration & dosage
• Endotoxins/blood
• Enteral Nutrition
• Liver/microbiology
• Lymph Nodes/microbiology
• Male
• Mesentery
• Rats
• Rats, Sprague-Dawley
• Shock, Hemorrhagic/blood
• Shock, Hemorrhagic/microbiology
• Spleen/microbiology
• Triglycerides/blood

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Pretreatment With High-Fat Enteral Nutrition Reduces Endotoxin and Tumor Necrosis Factor-?? and Preserves Gut Barrier Function Early After Hemorrhagic Shock

Gram-negative sepsis is a potentially fatal clinical syndrome characterized by a proinflammatory response (tumor necrosis factor-alpha) to bacterial (endo)toxins and gut barrier function loss. Recently, we found that high-fat enteral nutrition protects against late bacterial translocation in a model of hemorrhagic shock in rats. However, the basis for this protection is unknown. We hypothesized that the observed protection is the result of an early inhibition of endotoxin and the subsequent inflammatory response resulting in a preserved gut barrier function. Sprague-Dawley rats were divided into a group that was starved overnight (HS-S), fed with a low-fat enteral diet (HS-LF) or fed wih a high-fat enteral diet (HS-HF), and subsequently subjected to a nonlethal hemorrhagic shock. Ninety minutes after hemorrhage, arterial endotoxin significantly decreased in HS-HF rats (4.0 +/- 0.6 pg/mL) compared with HS-LF rats (10.7 +/- 0.9 pg/mL, P = 0.002) and HS-S rats (15.2 +/- 2.2 pg/mL P = 0.001). Interestingly, arterial tumor necrosis factor-alpha was also decreased in HS-HF rats (17.9 +/- 10.4 pg/mL) compared with HS-LF (83.5 +/- 16.7 pg/mL, P < 0.01) and HS-S rats (180.9 +/- 67.9 pg/mL, P < 0.02). Loss of tight junction structure (ZO-1) observed in ileum and colon of control hemorrhagic shock rats was prevented in HS-HF rats. In parallel, intestinal barrier function was preserved in HS-HF rats, evidenced by a reduced permeability to horseradish peroxidase (P < 0.05), less bacterial invasion, and a 10-fold reduction of bacterial translocation early after hemorrhagic shock. This report describes a new strategy to nutritionally prevent endotoxemia, the subsequent inflammatory response and gut barrier failure following hemorrhagic shock. High-fat enteral nutrition requires further evaluation as an intervention to prevent a potentially fatal systemic inflammatory response in patients at risk for sepsis.

Gastric PgCO 2 and Pg-aCO 2 gap are related to d-lactate and not to l-lactate levels in patients with septic shock

OBJECTIVE

Intestinal ischemia causes an increase in lactate production and gastric intramucosal carbon dioxide partial pressure (PgCO(2)). However, no linear relationship between systemic l-lactate levels and gastric tonometry during intestinal ischemia has been found, probably since l-lactate is rapidly cleared from the circulation by the liver. In contrast, the rate of d-lactate clearance from the circulation by the liver is considerably lower than that of l-lactate, and d-lactate may therefore be more closely related to measurements of gastric tonometry than l-lactate values.

DESIGN AND SETTING

Prospective, observational study in a university-affiliated mixed intensive care unit.

SUBJECTS

Twenty critically ill patients with septic shock.

MEASUREMENTS AND RESULTS

During the first 24 h of admission to the intensive care unit at least two blood samples were taken for d- and l-lactate measurements and arterial blood gases, Simultaneously, gastric PgCO(2) was measured using capnographic tonometry. The intramucosal-arterial PCO(2) gap was calculated using gastric intramucosal PgCO(2) and arterial PCO(2) from arterial blood. d-Lactate was significantly correlated to PgCO(2) values and to the mucosal-arterial PCO(2) gap. There was no relationship between l-lactate and PgCO(2) or the mucosal-arterial PCO(2) gap. d-lactate and l-lactate values were significantly correlated.

CONCLUSIONS

During sepsis intestinal production of d-lactate is related to gastric intramucosal PCO(2). No such relationship was found between l-lactate values and PgCO(2)

Lipopolysaccharide (LPS)-binding protein mediates LPS detoxification by chylomicrons

Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with chylomicrons and enhance the amount of LPS binding to chylomicrons in a dose-dependent fashion. In addition, LBP accelerated LPS binding to chylomicrons. This LBP-induced interaction of LPS with chylomicrons prevented endotoxin toxicity, as demonstrated by reduced cytokine secretion by PBMC. When postprandial circulating concentrations of chylomicrons were compared with circulating levels of low density lipoprotein, very low density lipoprotein, and high density lipoprotein, chylomicrons exceeded the other lipoproteins in LPS-inactivating capacity. Furthermore, highly purified lipoteichoic acid, an immunostimulatory component of Gram-positive bacteria, was detoxified by incubation with LBP and chylomicrons. In conclusion, our results indicate that LBP associates with chylomicrons and enables chylomicrons to rapidly bind bacterial toxin, thereby preventing cell activation. Besides a role in the detoxification of bacterial toxin present in the circulation, we believe that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxin.

Increased hepatosplanchnic inflammation precedes the development of organ dysfunction after elective high-risk surgery

This study investigated the relationship of the hepatosplanchnic production and uptake of inflammatory mediators, hepatosplanchnic perfusion, and outcome during major abdominal surgery to evaluate the hypothesis that regional production of inflammatory mediators precedes the development of hepatic dysfunction. This retrospective analysis of data and blood samples collected during a randomized controlled clinical trial included high-risk surgical patients undergoing major abdominal surgery in a 24-bed university-afilliated intensive care unit. Patients were divided into a subgroup that developed hepatic dysfunction (HD+) postoperatively and a subgroup without hepatic dysfunction (HD-). Hepatic vein and arterial plasma levels of IL-6, IL-8, s-E-selectin, s-ICAM-1, and the TNF-receptors 55 and 75 were measured, and the flux was calculated by multiplying the difference in hepatic vein minus arterial levels of the mediators by the hepatosplanchnic flow. Systemic (thermodilution) and total hepatosplanchnic blood flow (using indocyanine green [ICG]-dilution method) and gastric intramucosal pH (pHi) were assessed preoperatively, 4, 24, and 36 h postoperatively. Of a total of 26 patients, 6 patients developed hepatic dysfunction after their abdominal surgery (mean 6 days postoperatively). The number of sepsis-related deaths and postoperative days on the ventilator were significantly higher in this group. A higher production of IL-8, TNF-receptor-75 and 55 in the hepatosplanchnic area in the HD+ subgroups was found, which preceded the development of organ dysfunction (P = 0.04, P = 0.02, and P = 0.02, respectively). Moreover, the uptake of s-ICAM-1 was significantly increased in this subgroup. Furthermore, total hepatosplanchnic blood flow was significantly higher and pHi was significantly lower in the HD+ group, whereas global hemodynamic data were similar in the two subgroups. In conclusion, the development of postoperative organ dysfunction is preceded by an increased regional inflammatory response, indicated by an increased soluble TNF-receptor shedding and IL-8 production from the hepatosplanchnic area together with an increased uptake of s-ICAM-1. Moreover, an increased total hepatosplanchnic blood flow with intramucosal acidosis was associated with this regional inflammatory response.

Leptin and soluble leptin receptor levels in obese and weight-losing individuals

To investigate soluble leptin receptor (sLR) in plasma, specific anti-sLR monoclonal antibodies were developed. Western blot analysis and size exclusion fractionation demonstrated sLR in plasma with a molecular mass of approximately 180,000. Next to this, the presence of sLR-leptin complexes in plasma was confirmed. Using the developed monoclonal antibodies, a specific sLR ELISA was developed, which measured in plasma both free and sLR bound to leptin. sLR appeared to inhibit leptin concentrations measured in four different leptin assays indicating that these assays primarily measure free leptin and underestimate the total leptin present in plasma. Furthermore, plasma levels of sLR and leptin were measured in 21 lean individuals and in 30 morbidly obese subjects before and 3, 6, and 12 months after gastric restrictive surgery. Preoperatively, leptin concentrations significantly correlated with body mass index (r = 0.796, P < 0.001). In contrast, sLR significantly inversely correlated with body mass index (r = -0.294, P < 0.05). In lean subjects, the molar ratio of free leptin to sLR was 1:1, whereas in morbidly obese subjects a ratio of 25:1 was found. After weight loss due to surgery, leptin levels rapidly decreased and sLR levels slowly increased to reach normal values at 12 months postoperatively. We conclude that sLR levels are significantly decreased, whereas leptin levels are significantly increased in morbidly obese subjects compared with lean individuals.

Decreased plasma orexin-A levels in obese individuals

Orexin-A and -B stimulate appetite and food intake in rats. Orexins and orexin receptors are present in the hypothalamus as well as the enteric nervous system, the pancreas and the gut. The presence of orexins in peripheral blood, however, has not yet been reported. To determine whether orexin-A is present in human plasma and is related to body weight, we measured plasma orexin-A and leptin levels in a population with a body mass index (BMI) range from 19.8 to 59 kg/m(2). Plasma orexin-A levels correlated negatively and plasma leptin levels correlated positively with BMI. In obese and morbidly obese individuals, orexin-A levels were significantly lower and leptin levels were significantly higher when compared to normal. Our results support previous data suggesting that orexin-A acts also in a peripheral manner. The fact that lower levels of plasma orexin-A are present in obese individuals suggests that it is involved in the regulation of human energy metabolism.