Toxicogenomic profile of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the murine fetal heart: modulation of cell cycle and extracellular matrix genes

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and similar environmental contaminants have been demonstrated to be potent cardiovascular teratogens in developing piscine and avian species. In the present study, we investigated the effects of TCDD on gene expression during murine cardiovascular development. C57Bl6N pregnant mice were dosed with 1.5, 3.0, or 6.0 microg TCDD/kg on gestational day (GD) 14.5, and microarray analysis was used to characterize the global changes in fetal cardiac gene expression on GD 17.5. TCDD significantly altered expression of a number of genes involved in xenobiotic metabolism, cardiac homeostasis, extracellular matrix production/remodeling, and cell cycle regulation. Interestingly, while the AhR-responsive genes Cyp1A1, Cyp1B1, Ugt1a6, and Ahrr, were all induced by TCDD in the fetal murine heart, other AhR-responsive genes, Cyp1a2, Nqo1, and Gsta1, were not. Quantitative real-time polymerase chain reactions confirmed the changes in expression of several G1/S-type cyclins and extracellular matrix-related genes. These results demonstrate the global changes in cardiac gene expression that result from TCDD exposure of the fetal murine heart and implicate genes involved in cell cycle and extracellular matrix regulation in TCDD-induced cardiac teratogenicity and functional deficits.

Influence of cytokine and ICAM-1 gene polymorphisms on susceptibility to chronic pancreatitis

AIMS

To test the hypothesis that single nucleotide polymorphisms (SNPs) within genes (or their promoter regions) encoding cytokines, growth factors, and intercellular adhesion molecules modulate the risk of development of chronic pancreatitis (CP).

METHODS

DNA was extracted from peripheral blood leucocytes or formalin fixed, paraffin wax embedded tissue from 53 patients with CP and 266 healthy controls. SNPs within the interleukin 1beta (IL-1beta), IL-6, IL-8, tumour necrosis factor alpha (TNFalpha) and vascular endothelial growth factor (VEGF) gene promoter regions and the transforming growth factor beta1 (TGFbeta1) and intercellular cell adhesion molecule 1 (ICAM-1) genes were genotyped by the amplification refractory mutation system polymerase chain reaction or 5' nuclease (Taqman) techniques. Patient-control comparisons were made using 2 x 2 contingency tables and chi2 analyses.

RESULTS

A non-significant decrease in the frequency of the IL-8 -251 AA genotype and a non-significant increase in the frequency of the ICAM-1 +469 GA genotype was seen in patients compared with controls. No associations were identified between SNPs in the promoter regions of the IL-1beta, IL-6, or TNFalpha proinflammatory cytokines genes or the TGFbeta1 and VEGF genes and susceptibility to CP.

CONCLUSIONS

This preliminary study suggests that genetic polymorphism within several cytokine genes is unlikely to influence susceptibility to CP, but the possible role of IL-8 and ICAM-1 polymorphisms in the development of this disease requires further investigation.

Quality of life and functional long-term outcome after partial pancreatoduodenectomy: pancreatogastrostomy versus pancreatojejunostomy

BACKGROUND

To determine the effects of pancreatogastrostomy (PG) versus pancreatojejunostomy (PJ) as types of reconstruction after partial pancreatoduodenectomy on postoperative quality of life and long-term gastrointestinal morbidity, the outcomes of 104 patients (PG, n = 63; PJ, n = 41) were evaluated.

METHODS

To compare the two groups, the European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (QLQ-PAN 26) standard and an additional self-developed questionnaire were used. The mean time after surgery was 6.4 +/- 3.4 years.

RESULTS

In the PG group, there was a significant reduction of gastric acid reflux, gastroduodenal ulcers, and pain compared with before surgery. However, a significant increase in steatorrhea, intolerance toward larger meals, and aversion against certain foods were observed. In the PJ group, no significant change of preoperative symptoms was present except for jaundice. The incidence of diabetes mellitus and the need for pancreatic enzyme substitution had increased significantly but similarly in both groups. The global quality of life was identical in both groups of patients.

CONCLUSIONS

This analysis demonstrates that the global quality of life was not affected by the type of reconstruction after partial pancreatoduodenectomy. Patients who underwent PG had a significant reduction of gastric reflux, pain, and abdominal discomfort compared with before surgery. Patients in both groups showed an impaired exocrine and endocrine pancreatic function of a similar extent.

Novel genomic targets in oxidant-induced vascular injury

To study the complex interaction between oxidative injury and the pathogenesis of vascular disease, vascular gene expression was examined in male Sprague-Dawley rats given 35 or 70 mg/kg allylamine, a synthetic amine converted to acrolein and hydrogen peroxide within the vascular wall. Vascular lesions and extensive vascular remodeling, coupled to increased production of 8-epi-PGF2alpha, nuclear localization of NFkappaB, and alterations in glutathione homeostasis, were observed in animals treated with allylamine for up to 20 days. Transcriptional profiling, immunohistochemistry, and in situ hybridization showed that genes involved in adhesion and extracellular matrix (ECM) (alpha(1) integrin, collagen), cytoskeletal rearrangements (alpha-smooth muscle actin, alpha-tropomyosin), and signal transduction (NFkappaB, osteopontin, and LINE) were altered by oxidant treatment. To evaluate mechanisms of gene dysregulation, cultured aortic smooth muscle cells were challenged with allylamine or its metabolites and processed for molecular analysis. These agents increased formation of reactive oxygen species and elicited changes in gene expression similar to those observed in vivo. Oxidative stress and changes in gene expression were inhibited by N-acetyl cysteine, a precursor of glutathione. These results indicate that genes along the ECM-integrin-cytoskeletal axis, in addition to LINE, are molecular targets in oxidant-induced vascular injury.

Persistent organ failure during the first week as a marker of fatal outcome in acute pancreatitis

BACKGROUND

In predicted severe acute pancreatitis, many patients develop organ failure and recover without local complications, and mortality is only 14-30%. It has been suggested that half of patients with progressive early organ failure may die, but there are no data to relate death or local complications to duration of early (week 1) organ failure.

AIMS

To determine mortality rates in patients with transient (<48 hours) and persistent (>48 hours) early organ failure and to show whether persistent organ failure predicts death or local complications.

PATIENTS

A total of 290 patients with predicted severe acute pancreatitis previously studied in a trial of lexipafant, recruited from 78 hospitals through 18 centres in the UK.

METHOD

Manual review of trial database to determine: the presence of organ failure (Marshall score > or =2) on each of the first seven days in hospital, duration of organ failure, and outcome of pancreatitis (death, complications by Atlanta criteria).

RESULTS

Early organ failure was present in 174 (60%) patients. After transient organ failure (n = 71), outcome was good: one death and 29% local complications. Persistent organ failure (n = 103) was followed by 36 deaths and 77% local complications, irrespective of onset of organ failure on admission or later during the first week.

CONCLUSION

Duration of organ failure during the first week of predicted severe acute pancreatitis is strongly associated with the risk of death or local complications. Resolution of organ failure within 48 hours suggests a good prognosis; persistent organ failure is a marker for subsequent death or local complications.

Urinary trypsinogen activation peptide as a marker of severe acute pancreatitis

BACKGROUND

Trypsinogen activation peptide (TAP) may be an early marker of severe pancreatitis. Previous studies have included all patients with organ failure in the group with severe pancreatitis, although patients with transient organ failure may have a good prognosis. The aim of this study was to determine the value of urinary TAP estimation for prediction of severity of acute pancreatitis, and to validate use of several markers of prediction of severity against a new, stringent definition of severity.

METHODS

Patients with acute pancreatitis were recruited within 24 h of onset of symptoms. Urine and blood samples were collected for 24 h, and Acute Physiology And Chronic Health Evaluation (APACHE) II (24 h), Ranson (48 h) and Glasgow (48 h) scores were calculated. Severe acute pancreatitis was defined by the presence of a local complication or the presence of organ failure for more than 48 h.

RESULTS

Urinary TAP levels were significantly greater in patients with severe pancreatitis than in those with mild disease during the first 36 h of admission. The highest of three estimations of TAP in the first 24 h was as effective as APACHE II at 24 h in predicting severity. At 24 h after admission, urinary TAP was better than C-reactive protein (CRP) in predicting severity. The combination of TAP and CRP at 24 h allowed identification of high- and low-risk groups. The new definition of severity excluded 24 of 190 patients with transient organ failure; none of these patients died.

CONCLUSION

Use of TAP improved early prediction of the severity of acute pancreatitis. Organ failure that resolves within 48 h does not signify a severe attack of acute pancreatitis.

An aqueous formulation of ??-linolenic acid with anti-proliferative action on human pancreatic cancer cell lines

Essential fatty acids, especially gamma-linolenic acid (GLA), have been shown to directly inhibit the growth of cancer cell lines in culture. The aim of this study was to see whether an aqueous formulation of GLA works as well as the lithium-based salt. We evaluated the effect of the 1-deoxy-1-methylamino-D-glucitol salt of GLA (MeGLA) on the growth of two human pancreatic cancer cell lines (Panc-1 and MIA PaCa-2) in vitro, and compared its effects with a previously studied formulation, lithium GLA (LiGLA). The effect of time exposure (2-7 days) and difference in concentration (0-1000 micromol/l) were studied using 96-well culture plates. Cell growth was assessed by MTT assay. Control experiments were performed with meglumine alone in similar concentrations. MeGLA had cytostatic and cytotoxic effects on pancreatic cancer cell lines with 50% growth inhibition at 30-100 micromol/l and cytotoxic effects at 60-250 micromol/l. The degree of growth inhibition increased with time of exposure to MeGLA. The anti-proliferative effects of MeGLA were similar to those previously observed with LiGLA. We conclude that MeGLA has equivalent anti-proliferative activity to LiGLA when tested in vitro against pancreatic cancer cell lines and is therefore a suitable alternative to LiGLA for investigation of the in vivo activity of GLA against pancreatic adenocarcinomas.

Arris & Gale lecture. Regulation and responses of gallbladder muscle activity in health and disease

A complex relationship links biliary symptoms with the mechanisms of gallbladder emptying and the presence of gallstones. This relationship has been investigated by clinical studies of symptoms associated with gallstones, by investigation of gallbladder emptying and cholecystokinin (CCK) release in patients with gallstones, and after cholecystectomy, or truncal vagotomy, and in the irritable bowel syndrome (IBS). Laboratory studies examined receptor density on bovine gallbladder, and contractility of human gallbladder in response to a variety of stimuli was studied in vitro. A set of six symptoms associated with the presence of gallstones was identified; IBS appeared to be present in two-fifths of patients before cholecystectomy but only one-third of these patients had persistent IBS symptoms one year after operation. Gallbladder emptying studies confirmed the poor contraction of stone-bearing gallbladders; abnormal patterns of emptying were also found in patients with IBS. Gallbladder emptying and filling appear to be largely neurally regulated. CCK receptor density was very low in gallbladder tissue, suggesting that receptors on nerve cells might mediate the action of CCK. Relaxation of gallbladder muscle was mediated by adrenergic and nitrergic nerves. The inflammatory mediator bradykinin, however, had a strong direct action on muscle cells to cause gallbladder contraction. The work reported here gives an overview of the symptoms and mechanisms of disease associated with the presence of stones in the gallbladder.

CT colonography: determination of optimal CT technique using a novel colon phantom

The aim of this study was to determine the thickest slice at the lowest radiation dose for detection of colon polyps larger than 5mm in diameter at computed tomographic (CT) colonography. A colon phantom containing haustral folds, flexures, and straight segments was constructed of borosilicate. One hundred forty simulated polyps (5, 7, 10, and 12 mm) of various shapes (sessile, flat, and pedunculated) were attached at different colon locations (wall, base of fold, on the fold and fold tip). Polyps were positioned parallel, perpendicular, and oblique to the CT gantry. The air-filled phantom was scanned at different slice thicknesses (1.25-5 mm) and x-ray tube currents (5-308 mA). All polyps were identified in all data sets except one (1.25 mm slice thickness, 5 mA). In this acquisition, image noise reduced polyp visibility, and five of 140 (3%) polyps could not be identified. Unidentified polyps were 5 mm, flat or sessile in shape, located on the colon wall or base of the fold, and oblique or parallel to CT gantry. All tested CT techniques provided optimal polyp detection except settings at 1.25 mm and 5 mAs. Thin collimation (<5 mm) scans may not be necessary to detect clinically significant polyps.

Combination of APACHE-II score and an obesity score (APACHE-O) for the prediction of severe acute pancreatitis

BACKGROUND

The advent of specific therapeutic or preventive treatments for severe acute pancreatitis creates a need to determine the risk of complications for each individual. Scoring systems used in acute pancreatitis identify groups of patients at risk of complications, but the pancreatitis-specific scores require 48 h of hospital admission to give full information. The APACHE-II score is useful within 24 h, but ignores simple clinical features, such as obesity, known to predict severity. The aim of this study was to evaluate a combination of the APACHE-II score with an obesity score in patients with acute pancreatitis, to predict severity using information available during the first 24 h of hospital admission.

METHODS

Data were collected prospectively from 186 consecutive patients with acute pancreatitis, to allow calculation of the APACHE-II score and body mass index (BMI). BMI was categorised as normal (score = 0), overweight (BMI 26-30: score = 1), or obese (BMI >30: score = 2). A logistic regression model was used to identify factors significantly associated with complications (Atlanta criteria; 104 complications in 60 patients).

RESULTS

Age, BMI and the acute physiology score independently predicted complications. Addition of the score for obesity to the APACHE-II score gave a composite score (APACHE-O) with greater predictive accuracy. At cut-off of >8, APACHE-O had sensitivity 82%, specificity 86%, positive predictive value 74%, negative predictive value 91% and overall accuracy 85%.

CONCLUSIONS

This study confirms that age, obesity and APACHE-II measured in the first 24 h of hospital admission can predict complications in acute pancreatitis. Combination of the APACHE-II and obesity scores by simple addition improved categorical prediction of severity (mild or severe) in patients with acute pancreatitis.