Reflux composition influences the level of NF-κB activation and upstream kinase preference in oesophageal adenocarcinoma cells.

Oesophageal adenocarcinoma (OA) incidence is rising and prognosis is poor. Understanding the molecular basis of this malignancy is key to finding new prevention and treatment strategies. Gastroesophageal reflux disease is the primary cause of OA, usually managed with acid suppression therapy. However, this often does little to control carcinogenic bile acid reflux. The transcription factor nuclear factor kappa B (NF-κB) plays a key role in the pathogenesis of OA and its activity is associated with a poor response to chemotherapy, making it an attractive therapeutic target. We sought to decipher the role of different bile acids in NF-κB activation in oesophageal cell lines using short, physiologically relevant exposure times. The effect of an acidic or neutral extracellular pH was investigated concurrently, to mimic in vivo conditions associated with or without acid suppression. We found that some bile acids activated NF-κB to a greater extent when combined with acid, whereas others did so in its absence, at neutral pH. The precise composition of an individual's reflux, coupled with whether they are taking acid suppressants may therefore dictate the extent of NF-κB activation in the oesophagus, and hence the likelihood of histological progression and chemotherapy success. Regardless of pH, the kinase inhibitor of κB kinase was pivotal in mediating reflux induced NF-κB activation. Its importance was confirmed further as its increased activation was associated with histological progression in patient samples. We identified further kinases important in acid or bile induced NF-κB signalling in oesophageal cells, which may provide suitable targets for therapeutic intervention.

Inducible nitric oxide synthase (iNOS) and nitric oxide (NO) are important mediators of reflux-induced cell signalling in esophageal cells.

Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS) has been implicated in both DNA damage induction and aberrant cell signalling in various tissue and cell backgrounds. We investigated here the role of iNOS and NO in DNA damage induction and nuclear factor-kappa B (NF-κB) signalling in esophageal cells in vitro. As esophageal adenocarcinoma develops in a background of Barrett's esophagus secondary to reflux disease, it is possible that inflammatory mediators like NO may be important in esophageal cancer development. We show that reflux components like stomach acid and bile acids [deoxycholic acid (DCA)] can induce iNOS gene and protein expression and produce NO generation in esophageal cells, using real-time PCR, western blotting and NO sensitive fluorescent probes, respectively. This up-regulation of iNOS expression was not dependent on NF-κB activity. DCA-induced DNA damage was independent of NF-κB and only partially dependent on iNOS and NO, as measured by the micronucleus assay. These same reflux constituents also activated the oncogenic transcription factor NF-κB, as measured by transcription factor enzyme-linked immunosorbent assay and gene expression studies with NF-κB linked genes (e.g. interleukin-8). Importantly, we show here for the first time that basal levels of NF-κB activity (and possibly acid and DCA-induced NF-κB) are dependent on iNOS/NO and this may lead to a positive feedback loop whereby induced iNOS is upstream of NF-κB, hence prolonging and potentially amplifying this signalling, presumably through NO activation of NF-κB. Furthermore, we confirm increased protein levels of iNOS in esophageal adenocarcinoma and, therefore, in neoplastic development in the esophagus.

In vitro and ex vivo models of extended reflux exposure demonstrate that weakly acidic mixed reflux heightens NF-kB-mediated gene expression.

The development of Barrett's esophagus and its progression to adenocarcinoma are clearly linked to reflux of acid and bile. Our objective in this study was to develop an optimized ex vivo biopsy culture technique to study the molecular signaling events induced after insult with individual refluxate constituents. We illustrate the utility of this method by showing results for NF-kB centered cell signaling, and compare the results with those obtained from esophageal cell lines. We show that upregulation of the two NF-kB target genes show differences in pH preference, with IL-8 being preferentially upregulated by DCA at neutral pH, and IkB being upregulated by neutral DCA, acidic DCA, and acid alone. This was found to be true in both cell lines and biopsy cultures. The maximum responses were noted in both models when mixed reflux (DCA at pH 6) was utilized, perhaps reflecting the pH preference of DCA (pKa 6.2). Both the optimized ex vivo models, and the in vitro cell lines show that bile and acid are capable of inducing NF-kB dependent gene expression, with some interesting differences in preferred transcriptional target. In conclusion, in both cells and cultured biopsies, similar reflux driven gene expression changes were noted, with maximum effects noted with DCA exposures at pH 6.

Aneuploidy involving chromosome 1 may be an early predictive marker of intestinal type gastric cancer.

Intestinal type gastric cancer is a significant cause of mortality, therefore a better understanding of its molecular basis is required. We assessed if either aneuploidy or activity of the oncogenic transcription factor nuclear factor kappa B (NF-kappaB), increased incrementally during pre-malignant gastric histological progression and also if they correlated with each other in patient samples, as they are both induced by oxygen free radicals. In a prospective study of 54 (aneuploidy) and 59 (NF-kappaB) consecutive patients, aneuploidy was assessed by interphase fluorescent in situ hybridisation (FISH) for chromosome 1. NF-kappaB was assessed by expression of interleukin-8 (IL-8), and in a subset, by immunohistochemistry (IHC) for active p65. Aneuploidy levels increased incrementally across the histological series. 2.76% of cells with normal histology (95% CI, 2.14-3.38%) showed background levels of aneuploidy, this increased to averages of 3.78% (95% CI, 3.21-4.35%), 5.89% (95% CI, 3.72-8.06%) and 7.29% (95% CI, 4.73-9.85%) of cells from patients with gastritis, Helicobacter pylori positive gastritis and atrophy/intestinal metaplasia (IM) respectively. IL-8 expression was only increased in patients with current H. pylori infection. NF-kappaB analysis showed some increased p65 activity in inflamed tissues. IL-8 expression and aneuploidy level were not linked in individual patients. Aneuploidy levels increased incrementally during histological progression; were significantly elevated at very early stages of neoplastic progression and could well be linked to cancer development and used to assess cancer risk. Reactive oxygen species (ROS) induced in early gastric cancer are presumably responsible for the stepwise accumulation of this particular mutation, i.e. aneuploidy. Hence, aneuploidy measured by fluorescent in situ hybridisation (FISH) coupled to brush cytology, would be worthy of consideration as a predictive marker in gastric cancer and could be clinically useful in pre-malignant disease to stratify patients by their cancer risk.

The bile acid deoxycholic acid has a non-linear dose response for DNA damage and possibly NF-kappaB activation in oesophageal cells, with a mechanism of action involving ROS.

Deoxycholic acid (DCA) is a secondary bile acid implicated in various cancers of the gastrointestinal (GI) tract. In oesophageal adenocarcinoma, DCA is believed to contribute to carcinogenesis during reflux where stomach contents enter the lower oesophagus. It is imperative that we understand the mechanisms whereby oesophageal carcinogens function in order that therapeutic options may be developed. We have previously shown that DCA can damage chromosomes and does so through its generation of reactive oxygen species (ROS). We show here, after detailed experiments, that DCA appears to have a non-linear dose response for DNA damage. DCA induces DNA damage (as measured by the micronucleus assay) at doses of 100 microM and higher in oesophageal OE33 cells, but fails to induce such DNA damage below this cut-off dose. We also show that in terms of NF-kappaB activation (as measured by up-regulation of two NF-kappaB target genes) by DCA, a similar dose response is observed. This dose-response data may be important clinically as DCA exposure to the oesophagus may be used as a way to identify the 10% of Barrett's oesophagus patients currently progressing to cancer from the 90% of patients who do not progress. Only quantitative studies measuring DCA concentrations in refluxates correlated with histological progression will answer this question. We further show here that ROS are behind DCAs ability to activate NF-kappaB as antioxidants (epigallocatechin gallate, resveratrol and vitamin C) abrogate DCAs ability to up-regulate NF-kappaB-controlled genes. In conclusion, low doses of DCA appear to be less biologically significant in vitro. If this were to be confirmed in vivo, it might suggest that reflux patients with low DCA concentrations may be at a lower risk of cancer progression compared to patients with high levels of DCA in their refluxate. Either way, antioxidant supplementation may possibly help prevent the deleterious effects of DCA in the whole GI tract.

Obesity, metabolic syndrome and sleep apnoea: all pro-inflammatory states.

Obesity is associated with significant morbidity and mortality and is increasing in prevalence worldwide. Associated conditions include insulin resistance (IR), diabetes, hypertension and dyslipidaemia; a clustering of these has recently been termed as metabolic syndrome. Weight gain is a major predictor of the metabolic syndrome with waist circumference being a more sensitive indicator than body mass index as it reflects both abdominal subcutaneous adipose tissue and visceral adipose tissue (VAT). VAT has more metabolic activity and secretes a number of hormones and pro-inflammatory cytokines which are linked with the metabolic abnormalities listed above. Central obesity also increases the risk of obstructive sleep apnoea syndrome (OSAS), where the sleep disordered breathing may also independently lead to/or exacerbate IR, diabetes and cardiovascular risk. The contribution of OSAS to the metabolic syndrome has been under-recognized. The putative mechanisms by which OSAS causes or exacerbates these other abnormalities are discussed. We propose that activation of nuclear factor kappa B by stress hypoxia and/or by increased adipokines and free fatty acids released by excess adipose tissue is the final common inflammatory pathway linking obesity, OSAS and the metabolic syndrome both individually and, in many cases, synergistically.

Nutritional deficiencies after bariatric surgery.

A current review of nutritional complications following bariatric procedures is presented, focusing on the most common and clinically important deficiencies. A brief outline of nutritional supplementation protocol is presented, highlighting the need for a standardized, national or international set of guidelines for pre- and postoperative nutritional screening and appropriate supplementation.

Laparoscopic gastric bypass in a patient with malrotation of the intestine.

The increased prevalence of morbid obesity is associated with an increased prevalence of obesity co-morbidities. Bariatric surgery is generally the only effective treatment. Gastric bypasses are the most common bariatric operation in many countries, and more than half are performed laparoscopically. We discuss the challenges encountered in performing laparoscopic gastric bypass and cholecystectomy in a morbidly obese patient who was found to have malrotated small and large bowel when the procedure started. In the absence of past gastrointestinal symptoms and investigations, there is no way of diagnosing this anomaly preoperatively. However, when such a problem is posed at the time of surgery, it is safe to perform the planned operation if the surgeon has experience and skills in advanced laparoscopic techniques.

Gastro-ileal stenosis and gastroparesis after a biliopancreatic diversion.

Biliopancreatic diversion (BPD) is a very effective bariatric operation particularly for super-obese patients (BMI > or = 50 kg/m(2)). We present the development of a stricture at the gastro-ileal anastomotic site, with subsequent dilatation and aperistalsis of the stomach in a female patient who had undergone a standard open Scopinaro BPD. The patient remained symptomatic and persisted in losing weight, despite endoscopic balloon dilatations of the stricture and surgical revision of the anastomosis. She finally underwent conversion to a standard Roux-en-Y proximal gastric bypass. We describe the development of the stricture after the use of the stapling gun, subsequent gastric dilatation and dysmotility.

Laparoscopic and minilaparotomy cholecystectomy: a randomized trial comparing postoperative pain and pulmonary function.

BACKGROUND: Upper abdominal surgery is associated with severe postoperative pain and a concomitant reduction in pulmonary function and oxygen saturation. Laparoscopic cholecystectomy is said to result in less postoperative pain compared with open cholecystectomy. METHODS: In a pragmatic, randomized trial, postoperative pain, opiate analgesic consumption, oxygen saturation, and pulmonary function (forced vital capacity, forced expiratory volume in 1 second, and peak expiratory flow rate) were assessed after laparoscopic (n = 67) and minilaparotomy (n = 65) cholecystectomy. RESULTS: Compared with minilaparotomy cholecystectomy, laparoscopic cholecystectomy was associated with lower linear analogue pain scores (median 40 vs 59, p < 0.001), lower patient-controlled morphine consumption (median 22 vs 40 mg, p < 0.001), a smaller reduction in postoperative pulmonary function (mean peak expiratory flow rate 64% of preoperative value vs 49%, p < 0.001), and better oxygen saturation (mean 92.9% vs 91.2%, p = 0.008). CONCLUSIONS: This study confirms that the postoperative pain and pulmonary changes associated with upper abdominal surgery are significantly reduced by the laparoscopic technique. These findings suggest that laparoscopic cholecystectomy may result in a reduced risk of postoperative pulmonary complications.

Early outcome after open versus extraperitoneal endoscopic tension-free hernioplasty: a randomized clinical trial.

BACKGROUND: The use of minimal access surgery for repair of groin hernias is controversial. The aim of this study was to compare endoscopic tension-free hernia repair with open tension-free hernia repair within a randomized clinical trial. METHODS: One hundred twenty patients were randomized by four surgeons during a 1-year period. Early outcome measures were then analyzed by intention to treat. RESULTS: Median postoperative pain scores (63 [interquartile range (IQR), 23 to 81] versus 35 [IQR, 17 to 62]; p = 0.004) and analgesia requirements (2.5 [IQR, 2 to 4] doses verus 2.0 [IQR, 1 to 3] doses; p = 0.0008) were significantly less for patients undergoing endoscopic hernia repair. Hospital stay (1 [IQR, 0 to 1] day versus 2 [IQR, 1 to 2] days; p < 0.0001) was also significantly reduced for the endoscopic group. Wound complications occurred significantly more frequently in the open group. No difference in pulmonary function or metabolic response to trauma (interleukin-6, C-reactive protein, glucose, albumin) was observed between the groups. CONCLUSIONS: This study shows significant short-term advantages for endoscopic tension-free repair over open tension-free repair. However, larger studies with a longer follow-up period are required to establish the relative merits of both procedures in the management of patients with groin hernias.

What effect does the duration of an inguinal hernia have on patient symptoms?

BACKGROUND: Despite the fact that repair of an inguinal hernia is one of the most common operations performed in general surgery, we have very little information on the natural history of the untreated hernia. The aim of this study was to evaluate the association between hernia symptoms and the duration the patients had their hernias before presentation to a surgical outpatient department for an elective or emergency operation. STUDY DESIGN: Data were gathered prospectively on a consecutive series of 699 patients admitted to two University Departments of Surgery for scheduled operations for an inguinal hernia. RESULTS: More than one third (267) of patients had their hernias for 1 year or longer, up to 65 years, before presentation. The most common symptom on presentation was pain or discomfort at the hernia site, which occurred in 457 (66%) patients. The cumulative probability of pain increased with time to almost 90% at 10 years. The hernia had become irreducible in 48 patients (6.9%). The cumulative probability of irreducibility increased from 6.5% (95% confidence interval 4% to 9%) at 12 months to 30% (95% confidence interval 18% to 42%) at 10 years. Leisure activities were affected in 29% of patients although only 13% of patients had to take time off work because of hernia-related symptoms. Only two patients (0.3%) required resection of infarcted bowel or omentum. CONCLUSIONS: Because many patients with an inguinal hernia are asymptomatic or mildly symptomatic, prospective clinical trials to assess the role of operations for such hernias are required.

Fluctuations in the secretion of pancreatic enzymes between consecutive doses of octreotide: implications for the management of fistulae.

OBJECTIVE: To determine whether variations in pancreatic enzyme secretion between consecutive subcutaneous administrations of octreotide explain why octreotide takes longer than somatostatin to facilitate the closure of gastrointestinal fistulae. METHODS: Pancreatic enzyme secretion was studied over a 3-day period in a patient with a catheter left in the pancreatic duct postoperatively. On days 1 and 3 the patient did not receive octreotide (control days) but on day 2 he received subcutaneous octreotide 100 micrograms every 8 h. Pancreatic juice was collected at 2-h intervals over the 3-day period. RESULTS: On the day of octreotide treatment, the patient's pancreatic secretory volume and protein output were significantly reduced (P < 0.001, Mann-Whitney U-test) compared with the 2 control days. The pancreatic secretory volume decreased markedly after the first injection of octreotide and remained low for the duration of the treatment period. The enzyme concentration of the pancreatic juice was also markedly reduced after the first injection of octreotide. However, approximately 4h after each octreotide injection the protein concentration of the pancreatic juice began to rise progressively, peaking approximately 6h after each administration of the analogue. CONCLUSION: Subcutaneous administration of octreotide produces a sustained decrease in the volume of pancreatic juice secreted, but enzyme secretion rises progressively between consecutive administrations of the analogue. The net effect is therefore the production of low volumes of pancreatic juice with a high enzyme concentration between consecutive injections of octreotide, which may delay the healing of the fistula tract. This may explain why longer treatment periods are required to achieve fistula closure with octreotide than with somatostatin, particularly in the case of pancreatic fistulae.

The detection of mutations induced in vitro in the human p53 gene by hydrogen peroxide with the restriction site mutation (RSM) assay.

We have analysed five mutation hotspots within the p53 gene (codons 175, 213, 248, 249, and 282) for mutations induced by hydrogen peroxide (H(2)O(2)), employing the restriction site mutation (RSM) assay. In addition, four other restriction sites covering non-hotspot codons of exons 5-9 of the p53 gene (codons 126, 153/54, 189 and the 3' splice site of exon 9) were analysed by the RSM assay for H(2)O(2)-induced mutations. Two cell types were concurrently analysed in this study, i.e. primary fibroblast cells and a gastric cancer cell line. Using the RSM assay, H(2)O(2)-induced mutations were only detected in exon 7 of the p53 gene. This was true for both cell types. These mutations were mainly induced in the Msp I restriction site (codon 247/248) and were predominantly GC to AT transitions (71%). Hence these GC to AT mutations were presumably due to H(2)O(2) exposure, possibly implicating the 5OHdC adduct, which is known to induce C to T mutations upon misreplication. Importantly, this study demonstrates that the RSM methodology is capable of detecting rare oxidative mutations within the hotspot codons of the p53 tumour suppressor gene. Hence, this methodology may allow the detection of early p53 mutations in pre-malignant tissues.

Induced hepatic arterial blockade by degradable starch microspheres in the rat.

Degradable starch microspheres (DSM, Spherex) have been shown to cause intermittent blockage of hepatic arterial flow and to increase the concentration of regionally injected cytotoxics. The Spherex monitoring system has been developed by Pharmacia, Sweden to establish the correct dose of DSM to optimize hepatic arterial blockade. Groups of normal rats received varying dosages of DSM and co-injected methylene diphosphonate (MDP) in order to reproduce the effect of reduction of passing fraction and marker flow rate as determined by the Spherex monitoring system. A flow reduction and significant decrease in passing fraction was achieved on injection of 4 mg of DSM via the hepatic artery.

A model of the hepatic perfusion index in the rat.

The hepatic perfusion index (HPI) is an indicator of the relative hepatic arterial to total liver blood flow as measured by dynamic flow scintigraphy. Hitherto, accurate assessment of the HPI in small animals has not been possible because of methodological difficulties. A reproducible method for measuring the HPI by dynamic scintigraphy in rats is described using a rapid intraventricular bolus administration of 0.04 ml 99Tcm sulphur colloid. There was no significant difference between the HPI determined by dynamic scintigraphy and and that calculated from absolute measurements of hepatic arterial and total liver blood flow. These results indicate that the HPI derived by dynamic scintigraphy in the rat is a true estimate of the ratio of the hepatic arterial to total liver blood flow.

Changes in the hepatic perfusion index during the growth and development of experimental hepatic micrometastases.

Micrometastases were induced in Fisher rats using an intraportal inoculation of 0.2 ml of 8 x 10(7) Walker carcinosarcoma cells. A control group received normal saline. The hepatic perfusion index (HPI) was measured during the growth and development of micrometastases. The HPI at 4 days (0.51 +/- 0.008) and at 6 days (0.65 +/- 0.16) was significantly raised when compared to controls (0.31 +/- 0.07) and at 2 days after inoculation (0.31 +/- 0.06). Hepatic artery flow did not change throughout the study period. However, portal venous inflow was decreased significantly at 4 and 6 days (0.57 +/- 0.16 and 0.55 +/- 0.11) when compared to controls (0.96 +/- 0.34). These results indicate that the change in the hepatic perfusion index is related to a decrease in portal venous inflow. The decrease in portal venous inflow could be a mechanical effect of the micrometastases on intrahepatic blood flow or to increased arteriovenous shunting.

The use of lexipafant in the treatment of acute pancreatitis.

The pathophysiology of systemic organ failure in acute pancreatitis has been the subject of debate for many years but there is growing evidence that increase production of pro-inflammatory cytokines plays an important role. from this work and from the results of studies in experimental pancreatitis there exists a rationale for the use of PAF antagonists in the treatment of acute pancreatitis. Two pilot studies have now demonstrated a beneficial effect of the PAF antagonist Lexipafant on acute pancreatitis which may lead to an important advance in the treatment of these patients. A multicentre trial aiming to recruit 300 patients with severe acute pancreatitis is now underway in the UK, the results of which will be awaited with interest.

Laparoscopic fundoplication: learning curve and patient satisfaction.

AIMS: Laparoscopic fundoplication is now accepted as the optimal surgical option for the management of selected cases of gastro-oesophageal reflux disease. The principal aim of this study was to evaluate the learning curve experience of two consultant surgeons in the technique of laparoscopic fundoplication (LF). Additional variables assessed were total number of cases, preoperative investigations, conversion rate, duration of operation, ASA grade, morbidity, mortality, necessity of further procedures, and patient satisfaction rate. PATIENTS AND METHODS: Retrospective case-note analysis of all adult patients who underwent fundoplication under the care of two consultant general surgeons over a 3-year period from January 1997 to December 1999. RESULTS: A total of 61 patients were included, 31 males and 30 females, with a median age of 46 years (range, 21-73 years). Of the patients, 90% were either ASA 1 or 2. The mean time for which the 24-h pH < 4 was 20.5% (95% CI, 15.3-25.7). Of the 61 patients, 6 were operated on by open technique, for medical reasons and previous abdominal procedures. Out of the remaining 55 patients, 13 had to be converted (23.6%). Mean operating times were 120 min for LF, 85 min for open operation and 142 min for LF plus conversion. There was a significant decline in conversion rate with time (P < 0.002). Mortality was nil. One patient had a perforation of the cricopharyngeus secondary to insertion of a bougie. The mean length of hospital stay following the laparoscopic technique was 3.4 days compared to 8.7 days following the open technique. Overall, 59 patients (96%) were happy with the result, and the operation failed in 2 patients. Five patients (8%) needed endoscopic dilatation in the first few weeks after the operation. CONCLUSIONS: The results show that LF is a safe procedure, takes longer than open procedure, and has an acceptable morbidity. Experience with the technique reduces the need for conversion. The mean length of hospital stay is significantly less and there is a high level of patient satisfaction.

Randomised trial of octreotide for long term management of cirrhosis after variceal haemorrhage.

OBJECTIVE: To assess the efficacy of long term octreotide as adjuvant treatment to programmed endoscopic sclerotherapy after acute variceal haemorrhage in cirrhotic portal hypertension. DESIGN: Randomised clinical trial. SETTING: University hospital. SUBJECTS: 32 patients with cirrhotic portal hypertension. INTERVENTIONS: Programmed injection sclerotherapy with subcutaneous octreotide 50 micrograms twice daily for 6 months, or programmed injection sclerotherapy alone. MAIN OUTCOME MEASURES: Episodes of recurrent variceal bleeding and survival. RESULTS: Significantly fewer patients receiving combined octreotide and sclerotherapy had episodes of recurrent variceal bleeding compared with patients given sclerotherapy alone (1/16 v 7/16; P = 0.037, Fisher's exact test), and their survival was significantly improved (P < 0.02, log rank test); this improvement was maintained for 12 months after the end of the study. Combined treatment also resulted in a sustained decrease in portal pressure (median decrease -6.0 mm Hg, interquartile range -10 to -4.75 mm Hg, P = 0.0002) compared with sclerotherapy alone (median increase 1.5 mm Hg, interquartile range 0.25 to 3.25 mm Hg), as well as a significant improvement in liver function as assessed by plasma concentrations of bilirubin, albumin, and alanine aminotransferase and by hepatocyte metabolism of aminopyrine labelled with carbon-14. CONCLUSION: Long term octreotide may be a valuable adjuvant to endoscopic sclerotherapy for acute variceal haemorrhage in cirrhotic portal hypertension.