Changes in markers of oxidative stress and DNA damage in human visceral adipose tissue from subjects with obesity and type 2 diabetes

AIMS

In the past 30 years, prevalence of obesity has almost trebled resulting in an increased incidence of type 2 diabetes mellitus and other co-morbidities. Visceral adipose tissue is believed to play a vital role, but underlying mechanisms remain unclear. Our aim was to investigate changes in markers of oxidative damage in human visceral adipose tissue to determine levels of oxidative burden that may be attributed to obesity and/or diabetes.

METHODS

Visceral adipose tissue samples from 61 subjects undergoing abdominal surgery grouped as lean, obese and obese with type 2 diabetes mellitus, were examined using 3 different markers of oxidative stress. Malondialdehyde (MDA) concentration was measured as a marker of lipid peroxidation, telomere length and Comet assay as markers of oxidative DNA damage.

RESULTS

No significant difference in MDA concentration, telomere length and DNA damage was observed between groups, although longer telomere lengths were seen in the obese with diabetes group compared to the obese group (P<0.05). Lower MDA concentration and longer telomere length were seen in subjects with diabetes compared to those without (P<0.05). DNA damage, analysed via Comet assay, was significantly lower in subjects with diabetes compared to those without (P<0.05).

CONCLUSION

A paradoxical decrease in oxidative stress and DNA damage was observed in samples from subjects with type 2 diabetes mellitus. Further work is required to investigate this further, however this phenomenon may be due to an up regulation of antioxidant defences in adipose tissue.

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.

Adrenal insufficiency following bariatric surgery

A 35-year-old woman with morbid obesity and amenorrhoea underwent a bilo-pancreatic diversion (BPD). Surgery was successful with good weight loss, restoration of menstruation and almost immediately she conceived for the first time. She was commenced on routine vitamin supplements after surgery but failed to attend follow-up clinic. Five years later, she presented with limb girdle pains, lethargy, night blindness, skin pigmentation, amenorrhoea and dizziness. She had stopped taking supplements prescribed after the surgery. Investigations showed severe vitamin A and D deficiency along with iron and calcium deficiency. Her cholesterol was low at 3.5 mmol L⁻¹. Despite aggressive vitamin replacement, she continued to complain of lethargy and dizziness. Subsequently, three short adrenocorticotropic hormone-stimulation tests were suboptimal (basal cortisol: 196, 185 and 223 nmol L⁻¹; 30 min cortisol: 421, 453 and 435 nmol L⁻¹). She was subsequently commenced on adrenal replacement and her symptoms resolved and she conceived. We describe for the first time in the literature the unexpected finding of adrenal insufficiency following a BPD.

Temporal changes in glucose and insulin homeostasis after biliopancreatic diversion and laparoscopic adjustable gastric banding

BACKGROUND

Obesity surgery is associated with improvement in type 2 diabetes mellitus. Our aim was to examine the effects of biliopancreatic diversion (BPD) and laparoscopic adjustable gastric banding (LAGB) on the body mass index, fasting insulin level, glucose level, and insulin resistance in morbidly obese subjects with type 2 diabetes mellitus. The setting was the Department of Surgery, Morriston Hospital (Swansea, Wales, United Kingdom).

METHODS

A total of 13 morbidly obese patients (7 BPD, 6 LAGB) underwent serial measurements of fasting glucose and insulin at baseline, immediately after surgery (days 1-7), and 1, 6, and 12 months postoperatively. The homeostasis model of assessment-insulin resistance was calculated.

RESULTS

In the BPD group, the glucose levels had normalized by day 3 (5.6 ± 1 mmol/L) and the difference was statistically significant at 6 and 12 months postoperatively (5 ± .7 and 4.4 ± .5 mmol/L, respectively). The insulin levels had improved from day 1, and the difference was statistically significant at days 2, 5, 6, and 7 (19 ± 9, 14.2 ± 7, 15.2 ± 8, and 17.4 ± 8 mU/L, respectively). All diabetes medications were stopped on the fourth postoperative day. In the LAGB group, no statistically significant changes were seen in the glucose levels. Statistically significant changes in insulin were seen on days 1 and 2 (19 ± 13 and 13 ± 6.5 mU/L, respectively). The homeostatic model of assessment-insulin resistance had improved in both groups (BPD, 1.6 ± 1.2, P < .01; and LAGB, 4.3 ± 1.4, P < .05).

CONCLUSION

BPD causes immediate remission of type 2 diabetes mellitus. Leptin might play an important role in the early improvement of insulin resistance in fasting states after BPD. In the LAGB group, glucose homeostasis improved, but the patients still required diabetes medications, although the dosages were reduced.

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.

A Randomised, Cross-Over, Placebo-Controlled Study of Aloe vera in Patients with Irritable Bowel Syndrome: Effects on Patient Quality of Life

Background. Irritable bowel syndrome (IBS) is a chronic, difficult to treat condition. The efficacy of Aloe vera in treating IBS symptoms is not yet proven. The purpose of this study was to determine if Aloe vera is effective in improving quality of life. Methods. A multicentre, randomised, double-blind, cross-over placebo controlled study design. Patients were randomised to Aloe vera, wash-out, placebo or placebo, washout, Aloe vera. Each preparation (60 mL) was taken orally twice a day. Patient quality of life was measured using the Gastrointestinal Symptoms Rating Score, Irritable Bowel Syndrome Quality of Life, EuroQol and the Short-Form-12 at baseline and treatment periods 1 and 2. Results. A total of 110 patients were randomised, but only 47 completed all questionnaires and both study arms. Statistical analysis showed no difference between the placebo and Aloe vera treatment in quality of life. Discussion. This study was unable to show that Aloe vera was superior to placebo in improving quality of life. Drop outs and other confounding factors may have impacted on the power of the study to detect a clinically important difference. Conclusion. This study failed to find Aloe vera superior to placebo in improving quality of life proven Irritable Bowel Syndrome patients.

Influence of bariatric surgery on indices of cardiac autonomic control

BACKGROUND

Obesity is associated with reduced heart rate variability (HRV), reflecting detrimental changes in cardiac regulation by the autonomic nervous system (ANS). Weight loss reverses this change and ANS dysfunction is thought to have a role in obesity-related cardiac pathology. Few studies have examined the influence of weight-reduction (bariatric) surgery on cardiac autonomic control. This study therefore sought to assess longitudinal changes in indices of cardiac autonomic control following two types of bariatric procedure, laparascopic gastric banding (LGB) and biliopancreatic diversion (BPD).

METHODS

Eleven morbidly obese subjects aged 47.8 +/- 7.9 years (mean+/-SD) with BMI 48.2 +/- 6.9 kg x m(-2) underwent weight-reduction surgery: five received BPD and six received LGB. Holter ECG was recorded and HRV was quantified together with a QT variability index (QTVI), a complexity index (SampEn), and a fractal (scaling) index (DFAalpha). Repeated measures ANOVA compared the indices for the two groups as a function of time (1, 6 and 12 months follow-up).

RESULTS

BMI was reduced by up to 24% (p=0.008) post-surgery despite patients remaining obese at one-year follow-up. Several indices showed prompt and persistent improvement with progressive weight loss, QTVI being the most sensitive discriminator of recovery time (F(3,216)=16.86; p<0.0005; eta(2)=0.190). Autonomic responsiveness was functionally normal throughout. The bariatric procedures induced similar changes in cardiac autonomic control, despite their differing mechanisms of action.

CONCLUSIONS

This pilot study suggests that the mechanism responsible for improving cardiac regulation following bariatric surgery might be the weight loss itself. Furthermore, post-surgery improvement in QTVI implies that weight loss reduces the risk of ventricular arrhythmic events.

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.

Immunohistochemical study of nuclear factor-kappaB activity and interleukin-8 abundance in oesophageal adenocarcinoma; a useful strategy for monitoring these biomarkers

AIMS

To determine if immunohistochemistry (IHC) could be used to monitor nuclear factor-kappaB (NF-kappaB) activity in oesophageal adenocarcinoma and pre-malignant (Barrett's) oesophageal tissues, relative to normal oesophageal mucosa. The pro-inflammatory cytokine interleukin-8 (IL-8), a transcriptional target of NF-kappaB, was also studied to better understand NF-kappaB functionality; its RNA and protein levels were assessed in oesophageal tissues.

METHODS

IHC was employed using an antibody against the nuclear localisation sequence (NLS) of the p65 subunit as well as an antibody against IL-8. To assess NF-kappaB function, changes in gene expression of NF-kappaB controlled genes (IL-8 and I-kappaB) were also assessed in the histological sequence using real-time PCR. More global expression changes were also studied using membrane arrays.

RESULTS

IHC was effective at monitoring overall NF-kappaB activity and IL-8 abundance. This method also allowed NF-kappaB activity and IL-8 abundance to be pinpointed in specific cell types. There were significant increases in nuclear NF-kappaB activity and IL-8 abundance across the histological series. Gene expression analysis also showed consistent up-regulation of IL-8, confirming the IHC data and showing enhanced transcriptional NF-kappaB activity. I-kappaB (another NF-kappaB target) showed down-regulation in dysplastic and adenocarcinoma tissues. Down-regulation of I-kappaB gene expression may partly explain increased NF-kappaB activity.

CONCLUSION

IHC, using antibodies against the NLS of p65, may be useful in monitoring overall NF-kappaB activity in oesophageal tissues. As IHC is amenable to high-throughput screening (whereas traditional electrophoretic mobility shift assay methods are not), this may lead to the development of a better screening tool for early cancer risk.

Severe proctitis, perforation, and fatal rectal bleeding secondary to cytomegalovirus in an immunocompetent patient: report of a case

Cytomegalovirus (CMV) infection is associated with significant morbidity and mortality in immunocompromised patients. In immunocompetent individuals, the infection is usually subclinical but it can sometimes be life threatening. We describe a case of fatal CMV proctitis in a 71-year-old man following an Ivor-Lewis esophagectomy. After surgery he developed renal failure, methicillin-resistant Staphylococcus aureus pneumonia, and acute respiratory distress syndrome. He recovered but developed melena and massive fresh rectal bleeding. Sigmoidoscopy revealed severe proctitis and a biopsy was consistent with ischemia. Despite undergoing a proctectomy he continued to bleed and died despite every effort. The final histological examination of the rectum revealed a CMV infection.

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 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.

Parathyroid carcinoma

BACKGROUND

Parathyroid carcinoma is a rare malignancy affecting 0.5-5 per cent of all patients with primary hyperparathyroidism. This article reviews the literature on the pathogenesis, pathology, clinical features, diagnosis and management of parathyroid carcinoma.

METHODS

A Medline search was performed and all relevant English language articles published between 1970 and 2005 were retrieved. The search words included 'parathyroid carcinoma', 'pathology', 'genetics', 'management' and 'radiotherapy'. Secondary references were obtained from key articles.

RESULTS AND CONCLUSION

The exact aetiology of parathyroid carcinoma remains obscure. Recently, the HRPT2 gene has been implicated in its pathogenesis and may prove to be a genetic target in future. Surgical resection is the accepted 'gold standard'. There is now a growing consensus on the use of adjuvant radiotherapy as it has been shown to provide a survival benefit.

Generation of locus-specific probes for interphase fluorescence in situ hybridisation--application in Barrett's esophagus

Despite the wide range of probes commercially available for interphase fluorescence in situ hybridisation (FISH), the supply of locus-specific probes is limited to genes or chromosomal regions commonly altered in genetic diseases or during carcinogenesis. Generation of these probes is therefore desirable to accommodate individual research requirements. Hence, we detail the methodology required to design and produce custom locus-specific interphase FISH probes for any human genomic region of interest and their application was illustrated in cytogenetic investigations of Barrett's tumourigenesis. Previously utilising FISH, we observed that Barrett's tissues demonstrated chromosome 4 hyperploidy [Gut 52 (2003) 623], but as centromeric probes were used in this analysis, it was not known if the whole chromosome was amplified. We consequently generated single-copy sequence probes for the 4p16.3 and 4q35.1 subtelomeric loci. Multicolour FISH was subsequently performed on interphase preparations originating from patients with Barrett's esophagus at varying histological grades, thus demonstrating the whole region of chromosome 4 was amplified within the tissues. Additionally, probes for the DNA methyltransferase genes were produced to determine if gene dosage alterations were responsible for increasing methylation activity during Barrett's neoplastic progression. No significant alterations at the DNMT1 and DNMT3a loci were detected. An increased copy number of these genes is therefore not the basis for the hypermethylation commonly observed in this premalignant lesion.

Characterisation of p53 status at the gene, chromosomal and protein levels in oesophageal adenocarcinoma

p53 mutations and loss of heterozygosity have been commonly associated with oesophageal adenocarcinoma. In this investigation, the p53 status of a Welsh population of Barrett's-associated oesophageal adenocarcinomas were fully characterised at the gene sequence, chromosomal, mRNA and protein levels. In total, 31 tumours were examined for p53 gene sequence mutations using RFLP with sequencing, allelic loss of the gene was characterised by FISH, mRNA expression by p53 pathway signalling arrays and protein levels by p53 immunohistochemistry. In all, 9.6% of adenocarcinomas harboured p53 mutations, 24% displayed p53 allelic loss and 83% exhibited p53 protein accumulation. Point mutations and deletions of the gene did not coexist within the same samples. All samples containing p53 mutations also displayed positive immunostaining; however; in the majority of cases, p53 protein accumulation developed in the absence of mutations. The gene expression analysis demonstrated no differences in p53 and mdm-2 transcription levels between the p53 immunonegative and immunopositive samples, indicating other mechanisms underlie the proteins' overexpression. In conclusion, p53 mutations and deletions do not appear to be frequent events in oesophageal adenocarcinomas; however, abnormal accumulation of the protein is present in a vast majority of cases. P53 gene mutations are not the primary cause of protein overexpression--an alternative mechanism is responsible for the positive p53 immunohistochemistry detected.

The bile acid deoxycholic acid (DCA) at neutral pH activates NF-kappaB and induces IL-8 expression in oesophageal cells in vitro

Barrett's oesophagus patients accumulate chromosomal defects during the histological progression to cancer, one of the most prominent of which is the amplification of the whole of chromosome 4. We aimed to study the role that the transcription factor NF-kappaB, a candidate cancer- promoting gene, present on chromosome 4, plays in Barrett's oesophagus, using OE33 cells as a model. Specifically, we wanted to determine if NF-kappaB was activated by exposure to bile acid (deoxycholic acid) in oesophageal cells. We employed pathway specific cDNA microarrays and real-time PCR, to first identify bile acid induced genes and specifically to investigate the role of NF-kappaB. An NF-kappaB reporter system was used, as well as an inhibitor of NF-kappaB (pyrrolidine dithiocarbamate) to confirm the activation of NF-kappaB by bile. We show that physiological levels of DCA (100-300 microM) were capable of activating NF-kappaB in OE33 cells and inducing NF-kappaB target gene expression (particularly IkappaB and IL-8). Other gene expression abnormalities were also shown to be induced by DCA. Importantly, preliminary experiments showed that NF-kappaB activation by bile occurred at neutral pH, but not at acid pH. Acidic bile did however cause over-expression of the c-myc oncogene, as reported previously. Hence, we present data showing that NF-kappaB may be a key mediator of carcinogenesis in bile exposed Barrett's tissues. In addition, neutral bile acids appear to play a significant part in reflux induced gene expression changes. We postulate that the activation of the survival factor NF-kappaB by bile may be linked to the previous cytogenetic data from our laboratory showing the amplification of NF-kappaB's chromosome (chromosome 4), during Barrett's cancer progression. Hence chromosome 4 amplification may provide a survival mechanism for bile exposed oesophageal tissues via NF-kappaB.

Detection of p53 mutations in precancerous gastric tissue

Intestinal-type gastric cancer is preceded by gastritis and intestinal metaplasia. There is uncertainty regarding the stage at which genetic alterations in the p53 gene occur. Reactive oxygen species (ROS) may participate in the production of mutations and the inactivation of p53 is due to infection by the bacterium Helicobacter pylori. We have investigated whether alterations of the p53 gene can be detected in gastritis and intestinal metaplasia using the restriction site mutation assay. We also assessed the potential contribution of ROS to p53 inactivation using electron spin resonance spectroscopy (ESR) and correlated with the presence of H. pylori. In all, 35% of the gastritis samples and 45% of the intestinal metaplasia samples were found to contain mutations in exons 5–8 of the p53 gene. Electron spin resonance spectroscopy analysis showed a significant increase in free radical levels in gastritis samples compared with normal, intestinal metaplasia and cancer samples, suggesting that free radicals present in gastritis may contribute to p53 mutations. There was no significant difference in free radical levels between the H. pylori-positive and -negative groups. However, a small subpopulation of the H. pylori-negative patients had much higher levels of free radicals. This suggests a more prominent role for other factors in ROS production.

Chromosome 4 hyperploidy represents an early genetic aberration in premalignant Barrett's oesophagus

BACKGROUND AND AIMS

Characterisation of the underlying molecular mechanisms that promote Barrett's progression may ultimately lead to identification of potential predictive genetic markers that classify patients' malignant risk. In an attempt to understand these causative pathways, fluorescence in situ hybridisation (FISH) was used in this study to determine when specific genetic alterations arise during Barrett's associated neoplastic progression.

METHODS

Endoscopic cytology brushings were obtained from 28 patients with Barrett's metaplasia, 28 with dysplasia (20 low grade dysplasia (LGD) and eight with high grade dysplasia (HGD)), and seven with adenocarcinoma, together with paired control brushings from regions of normal proximal squamous cell epithelium. The exfoliated epithelial cells were washed and deposited onto slides. Probes specific for the centromeres of chromosomes 4, 8, 20, and Y, and locus specific probes for the tumour suppressor genes p16, p53, and Rb were subsequently hybridised.

RESULTS

Aneuploidy was found early in progression, with metaplastic tissues displaying increased copy numbers of chromosomes 4 and 8. Chromosome 4 hyperploidy was found in 89%, 90%, 88%, and 100% of metaplasias, LGD, HGD, adenocarcinomas, respectively, while chromosome 8 hyperploidy occurred in 71%, 75%, 100%, and 100% of patients with the respective staging. Loss of the p16 tumour suppressor gene also presented in metaplastic epithelium (7%) but most other genetic aberrations were only seen in HGD.

CONCLUSIONS

Genetic instability arises well before dysplasia in Barrett's oesophagus, with chromosome 4 and 8 hyperploidy representing the earliest and most common alterations identified. As these aberrations are widespread at all the premalignant stages, there may be genes on chromosomes 4 and 8 that are involved in both the initiation and progression of Barrett's oesophagus.

Early p53 mutations in nondysplastic Barrett's tissue detected by the restriction site mutation (RSM) methodology

Barrett's oesophagus is a premalignant condition whose incidence is rising dramatically. Molecular markers are urgently needed to identify Barrett's patients at the highest risk of cancer progression. To this end, we have used a rapid molecular technique, restriction site mutation (RSM), to detect low-frequency mutations in the p53 tumour suppressor gene in premalignant Barrett's tissues of cancer-free patients. In total, 38 endoscopically diagnosed Barrett's patients with a range of histological stages of Barrett's progression, plus four control patients without Barrett's oesophagus, were analysed for early p53 mutations. Tissue samples taken from these patients (93 samples in total) were analysed for the presence of low-frequency p53 mutations at hotspot codons: 175, 213, 248, 249, 282. In total, 13 of the 38 Barrett's patients were shown to possess a p53 mutation in at least one sample (no mutations in the four control patients). Although no statistically significant associations were found, p53 mutations reflected histological progression in Barrett's patients with p53 mutations found in 30% of metaplasia patients (P=0.4) and low-grade dysplasia patients (P=0.33) and 45% of high-grade dysplasia patients (P=0.15). Detected p53 mutations were mainly GC to AT transitions at CpG sites.

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.

Book reviews

Applied Surgical Anatomy – A Guide for the Surgical Trainee

M. A. Glasby, W. J. Owen and F. Kristmundsdottir (eds) 252 × 192 mm. Pp. 299. Illustrated. 1998. Oxford: Butterworth-Heinemann. £49.50.

A Guide to Laparoscopic Surgery

A. Najmaldin and P. Guillou 233 × 154 mm. Pp. 169. Illustrated. 1998. Oxford: Blackwell Science. £24.95.

Genetic pathways involved in the progression of Barrett's metaplasia to adenocarcinoma

BACKGROUND

The prediction of which patients with Barrett's metaplasia will develop cancer is difficult. Better genetic characterization of the condition may aid clinicians in devising more effective management and follow-up strategies.

METHODS

A review was undertaken of the accumulated genetic data relating to the progression of squamous epithelium to adenocarcinoma. The normal functions of a number of cancer-related genes are described and an explanation is given of how alterations in these genes interfere with normal cell processes and lead to cancer.

RESULTS AND CONCLUSION

The main genetic alterations accompanying the progression through dysplasia to adenocarcinoma were collated from 135 papers. The principal genetic changes implicated are the loss of p16 gene expression (by deletion or hypermethylation), the loss of p53 expression (by mutation and deletion), the increase in cyclin D1 expression, the induction of aneuploidy and the losses of the Rb, DCC and APC chromosomal loci.

Restriction enzymes in the analysis of genetic alterations responsible for cancer progression

BACKGROUND

Molecular approaches are increasingly being employed to dissect the genetic changes accompanying tumour formation. These methods can often be confusing to the non-specialist as they include complex molecular steps. This can reduce the usefulness of such molecular data to clinicians. The authors aim to aid interpretation of molecular studies in general by presenting a comprehensive review of one molecular approach, i.e. the use of restriction enzymes in molecular studies of tumour development.

METHOD

A review was made of the molecular studies that have employed restriction enzymes in gastrointestinal cancer research. These studies have used restriction enzymes to analyse point mutation induction, gene methylation status and the deletion of chromosomal loci. In addition, emphasis is placed on some of the important considerations for the molecular analysis of tumours that can affect the molecular data obtained.

RESULTS

Restriction enzyme digestion has played, and continues to play, a major role in analysing the genetic changes in cancer. Many adaptations of basic restriction enzyme methodologies have enhanced the application of this approach in cancer genetics.

CONCLUSION

The availability of 200 different restriction enzymes, each recognizing different sequences in DNA, has been invaluable in studying cancer genetics. It is hoped that current advances in protein engineering will facilitate the creation of novel restriction enzymes with tailor-made sequence specificities. This will further improve the applicability of restriction enzymes in cancer genetics.

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.

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.

Somatostatin analogs in oncology: a look to the future

In the past 15 years considerable advances have been made in our understanding of the molecular pharmacology of the mechanisms whereby somatostatin and its analogs mediate their direct and indirect antineoplastic effects. However, some important issues remain to be resolved, in particular the functional roles of the individual somatostatin receptors (SSTR-1-5) in tumor tissue and up- or downregulation of the hSSTRs with prolonged administration of somatostatin analogs. Answers to these questions are essential before we can maximize the therapeutic efficacy of somatostatin analogs in cancer. For example, is continuous administration more or less effective than intermittent therapy? The role of somatostatin analogs in the management of acromegaly and to a lesser extent neuroendocrine tumors is firmly established. The development of depot preparations of all 3 somatostatin analogs currently available for clinical use will undoubtedly improve both patient compliance and quality of life in patients with these conditions. There are only likely to be minor differences in the therapeutic efficacy of octreotide, lanreotide and vapreotide since all three analogs exert the majority of their antineoplastic effects via hSSTR-2 and hSSTR-5 and at the end of the day, price may well dictate which of these drugs oncologists use to provide symptomatic palliation of acromegaly and neuroendocrine tumors. Apart from some notable exceptions, somatostatin analog therapy has proven to be very disappointing in the management of advanced malignancy. Improvements in the management of solid tumors are likely to come only from combination therapy of somatostatin analogs with cytotoxic agents or other hormones in both advanced malignancy and in the adjuvant setting. Clinical trials with clear-cut objective outcome measures and health-related quality of life assessment are needed to evaluate the therapeutic efficacy of combination treatment in advanced malignancy and as an adjuvant to surgery. Particular attention needs to be paid to possible adverse effects of somatostatin analog therapy on the immune response to cancer. Further studies are required to establish whether the adverse effects of somatostatin analog therapy alone or in combination with cytotoxics or other hormones can be reversed with appropriate immunomodulatory treatment. Targeted somatostatin analog radiotherapy and chemotherapy are currently being investigated and the results of these studies are awaited with interest. Novel approaches using combinations of somatostatin analogs with antiangiogenic drugs or gene therapy are of particular interest and may provide important advances in the management of cancer in the not too distant future.

Relationship of carotenoid and vitamins A and E with the acute inflammatory response in acute pancreatitis

BACKGROUND

Inflammation and oxidative stress are believed to be important in the development of the systemic complications of acute pancreatitis. The fat-soluble vitamins A and E, and the carotenoids have antioxidant properties. The aim of this study was to assess the effect of acute pancreatitis on serum concentrations of vitamin antioxidants and to relate such changes to the degree of the inflammatory response.

METHODS

Thirteen consecutive patients with predicted severe acute pancreatitis were compared with 26 matched healthy controls. Five patients developed severe acute pancreatitis and three of these died. Vitamin antioxidant and C-reactive protein (CRP) levels were measured daily for up to 7 days.

RESULTS

Patients had significantly lower levels of antioxidants throughout the course of the study (P < 0.017). In patients there was a significant correlation between peak CRP and trough antioxidant levels (P < 0. 01). In patients with mild acute pancreatitis, the concentrations of retinol and beta-carotene at final review were significantly higher than those in patients with severe acute pancreatitis (P < 0.05). This coincided with a reduction in CRP level.

CONCLUSION

In acute pancreatitis, circulating concentrations of vitamin antioxidants are reduced and are inversely related to the rise in CRP level.

Pharmacokinetics of octreotide in patients with cirrhosis and portal hypertension; relationship between the plasma levels of the analogue and the magnitude and duration of the reduction in corrected wedged hepatic venous pressure

In healthy subjects octreotide is largely metabolised by the liver suggesting that the plasma half-life of the somatostatin analogue may be prolonged in patients with hepatic dysfunction. The aim of this study was therefore (a) to determine the pharmacokinetics of octreotide following its subcutaneous injection in 6 patients with cirrhosis and portal hypertension and (b) compare the magnitude and duration of the effects of intravenous administration of 250 micrograms somatostatin and 50 micrograms octreotide on corrected wedged hepatic venous pressure (WHVP) and to relate the findings to the plasma levels of the analogue 1 h after administration in 13 patients with cirrhosis and portal hypertension. Following subcutaneous administration of 50 micrograms octreotide the circulating half life (range 2.4 to 4.79 h) was prolonged whereas the clearance (range 2.101 to 4.775 L/h) was decreased compared to healthy controls. Intravenous bolus administration of 250 micrograms somatostatin or 50 micrograms octreotide resulted in a reduction in WHVP of approximately the same magnitude and duration despite appreciable quantities of the analogue in the blood 1 h after administration (1944 +/- 226 pg/ml). These results indicate that the circulating half-life of octreotide is prolonged in cirrhotics suggesting that the dosage regimens should be modified in such patients to avoid accumulation of the analogue in the blood which may result in undesirable side-effects or toxicity. Furthermore, since the magnitude and duration of the reduction in WHVP elicited by IV octreotide is similar to that observed with somatostatin, the analogue, like the native hormone, must be administered by continuous IV infusion to produce a sustained response and hence a therapeutic effect in the management of acute variceal bleeding.

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.

Prospective placebo-controlled randomized trial of lexipafant in predicted severe acute pancreatitis

BACKGROUND

Many patients with severe acute pancreatitis develop organ system failure during the first few days of illness, and this accounts for the majority of early deaths. No specific therapy is available and treatment remains supportive.

METHODS

In a randomized controlled trial conducted in 11 hospitals in the West of Scotland, 50 patients with predicted severe acute pancreatitis were selected from 188 screened over a 14-month period. Patients received placebo or lexipafant, a potent platelet-activating factor antagonist, by continuous intravenous infusion at a dose of 100 mg/day for up to 7 days. Early systemic complications were assessed by the measurement of organ failure scores.

RESULTS

There was a significantly greater fall in organ failure score in the treatment group during the 7 days of study (mean and median changes in organ failure score were 0.17 and 0 in the placebo group versus -1.42 and -1 in the treatment group; P = 0.003, Wilcoxon rank sum test), associated with trends towards a reduction in mortality and a reduced incidence of systemic complications.

CONCLUSION

These results suggest that lexipafant may be a useful adjunct to full supportive care in the early management of patients with severe acute pancreatitis.

Prospective placebo-controlled randomized trial of lexipafant in predicted severe acute pancreatitis

BACKGROUND

Many patients with severe acute pancreatitis develop organ system failure during the first few days of illness, and this accounts for the majority of early deaths. No specific therapy is available and treatment remains supportive.

METHODS

In a randomized controlled trial conducted in 11 hospitals in the West of Scotland, 50 patients with predicted severe acute pancreatitis were selected from 188 screened over a 14-month period. Patients received placebo or lexipafant, a potent platelet-activating factor antagonist, by continuous intravenous infusion at a dose of 100 mg/day for up to 7 days. Early systemic complications were assessed by the measurement of organ failure scores.

RESULTS

There was a significantly greater fall in organ failure score in the treatment group during the 7 days of study (mean and median changes in organ failure score were 0.17 and 0 in the placebo group versus -1.42 and -1 in the treatment group; P = 0.003, Wilcoxon rank sum test), associated with trends towards a reduction in mortality and a reduced incidence of systemic complications.

CONCLUSION

These results suggest that lexipafant may be a useful adjunct to full supportive care in the early management of patients with severe acute pancreatitis.

Gastric emptying in patients with constipation following childbirth and due to idiopathic slow transit

BACKGROUND

Idiopathic slow transit constipation (ISTC) is considered to be a heterogeneous condition in which patients have varying sites and degrees of delayed gastrointestinal transit. The majority of patients have pancolonic disease, and colectomy with ileocolorectal anastomosis has been the mainstay of surgical treatment. Severe constipation following traumatic childbirth is now being recognized and this subgroup of patients may have delayed transit confined to the rectosigmoid colon. In theory, proximal transit in these patients should be normal.

METHODS

Gastric emptying was studied in patients with constipation following childbirth or ISTC and in controls. After an overnight fast, both patients and controls received breakfast, which consisted of cornflakes, sugar and milk. The liquid marker 111In-labelled di-ethylene tri-amine penta-acetic acid (DTPA) was added to the milk. A solid marker, 99mTc-labelled colloid, was impregnated on to paper and sealed with cellulose. The t1/2 for gastric emptying was calculated.

RESULTS

Liquid phase emptying was normal in both constipation following childbirth and ISTC. Solid phase emptying was delayed significantly in ISTC compared with that in patients with constipation following childbirth and controls. In addition, half the patients with ISTC had delayed transit through the small bowel and proximal colon. Small bowel and colonic transit were normal in patients with constipation following childbirth.

CONCLUSION

Patients with constipation following childbirth represent a distinct subgroup with normal proximal gastrointestinal function. Gastric emptying studies may be helpful in selecting patients for surgical management of severe constipation.

Gastric emptying in patients with constipation following childbirth and due to idiopathic slow transit

BACKGROUND

Idiopathic slow transit constipation (ISTC) is considered to be a heterogeneous condition in which patients have varying sites and degrees of delayed gastrointestinal transit. The majority of patients have pancolonic disease, and colectomy with ileocolorectal anastomosis has been the mainstay of surgical treatment. Severe constipation following traumatic childbirth is now being recognized and this subgroup of patients may have delayed transit confined to the rectosigmoid colon. In theory, proximal transit in these patients should be normal.

METHODS

Gastric emptying was studied in patients with constipation following childbirth or ISTC and in controls. After an overnight fast, both patients and controls received breakfast, which consisted of cornflakes, sugar and milk. The liquid marker 111In-labelled di-ethylene tri-amine penta-acetic acid (DTPA) was added to the milk. A solid marker, 99mTc-labelled colloid, was impregnated on to paper and sealed with cellulose. The t1/2 for gastric emptying was calculated.

RESULTS

Liquid phase emptying was normal in both constipation following childbirth and ISTC. Solid phase emptying was delayed significantly in ISTC compared with that in patients with constipation following childbirth and controls. In addition, half the patients with ISTC had delayed transit through the small bowel and proximal colon. Small bowel and colonic transit were normal in patients with constipation following childbirth.

CONCLUSION

Patients with constipation following childbirth represent a distinct subgroup with normal proximal gastrointestinal function. Gastric emptying studies may be helpful in selecting patients for surgical management of severe constipation.

Randomized trial of different insufflation pressures for laparoscopic cholecystectomy

BACKGROUND

The factors affecting cardiorespiratory changes and postoperative pain after laparoscopic cholecystectomy are poorly understood. The aim of this study was to assess these changes in patients undergoing laparoscopic cholecystectomy at an insufflation pressure of 7.5 or 15 mmHg.

METHODS

Forty patients with similar preoperative characteristics were randomized, 20 to each group.

RESULTS

There were no significant differences in intraoperative heart rate or cardiac index although the latter fell significantly soon after insufflation in both groups. The fall in cardiac index lasted longer (7 versus 2 min) and coincided with a slower rise in mean arterial pressure in those having 15 mmHg insufflation. Changes in peak airway pressure, end-tidal carbon dioxide and arterial blood gases were similar. After operation the low-pressure group had significantly less pain, better preservation of pulmonary function and were discharged home sooner (P = 0.015).

CONCLUSIONS

Insufflation pressure significantly affects the haemodynamic changes and postoperative pain associated with laparoscopic cholecystectomy.

Increased monocyte cytokine production in association with systemic complications in acute pancreatitis

Tumour necrosis factor (TNF) alpha, interleukin (IL) 1 beta, IL-6 and IL-8 are thought to play a central role in the pathophysiology of sepsis but their role in acute pancreatitis is unknown. In the present study, monocytes were isolated from the peripheral blood of 26 patients with moderate or severe acute pancreatitis without biliary sepsis. Secretion of these cytokines in vitro was measured at intervals during the first week of illness. Sixteen patients developed systemic complications. Peak TNF-alpha secretion was significantly higher in patients who developed systemic complications (median (interquartile range (i.q.r.)) 18.5 (5.5-28.5) ng/ml) than in those with an uncomplicated course (3.7 (2.3-6.4) ng/ml, P < 0.01). Similarly, peak IL-6 and peak IL-8 secretion were significantly higher in the complicated group (IL-6: complicated median (i.q.r.) 48.9 (12.1-71.0) ng/ml, uncomplicated 16.3 (14.2-37.9) ng/ml, P < 0.05; IL-8: complicated 748 (643-901) ng/ml, uncomplicated 608 (496-749) ng/ml), P < 0.05). No significant difference in peak IL-1 beta secretion was observed between the two groups. Systemic complications of acute pancreatitis are associated with a significant increase in monocyte secretion of TNF-alpha, IL-6 and IL-8 suggesting that, as in sepsis, these cytokines play a central role in the pathophysiology of the disease.