Constantine E. Vagianos

Changes in aetiology and clinical outcome of acute upper gastrointestinal bleeding during the last 15 years.

Objectives The diagnostic and therapeutic approaches to patients with acute upper gastrointestinal bleeding have been improved during the last decades. The aim of this study was to compare the aetiology and clinical outcome of acute upper gastrointestinal bleeding (AUGIB) between two distinct periods during the last 15 years. Methods The causes of AUGIB and clinical outcome of 668 patients hospitalised with the problem in 1986–1987 were compared to 636 patients with AUGIB in 2000–2001. Patients were admitted to our hospital or they bled while they were inpatients for other reasons. No patient was excluded because of age or concurrent diseases. Endoscopic haemostasis with adrenaline injection for bleeding peptic ulcers was performed in the second period while no endoscopic method of haemostasis was performed in the first period. Results We observed an increase in the age of patients (56.5 ± 16.9 vs 62.9 ± 17.5 years, P < 0.0001) and the percentage of patients who received non-steroidal anti-inflammatory drugs (NSAIDs) before bleeding (from 44% to 63.5%, P < 0.0001). An increase in the diagnosis rate of gastric ulcer (12% vs 19.2%, P = 0.005) and varices (13.2% vs 3.3%, P < 0.001) with a simultaneous decrease in that of erosive gastroduodenitis (18.4% vs 7.2%, P < 0.0001) and duodenal ulcer (48.7% vs 33.3%, P < 0.0001) as a cause of bleeding was also observed. In peptic ulcer bleeding, emergency surgical haemostasis was reduced from 14% to 5.3%, P < 0.001. Overall mortality was also reduced from 5.2% to 3.1% and in peptic ulcer bleeding patients from 3.3% to 2.4%, respectively, but the differences are not statistically significant. Conclusion The aetiology of AUGIB has changed during the last 15 years probably due to the better therapeutic approach to chronic duodenal ulcers and increasing use of NSAIDs in the elderly. Emergency surgical haemostasis has been reduced but the reduction of mortality was not significant.

Growth hormone and insulin-like growth factor I protect intestinal cells from radiation induced apoptosis.

We studied whether programmed cell death (or apoptosis) is the predominant mechanism in radiation-induced cell damage to rat intestinal mucosa and investigated the mechanism of the protective effect of GH and IGF-I in the same model. Male albino Wistar rats were divided into four groups: controls, radiation, radiation plus GH and radiation plus IGF-I. Radiation was administered on the first day and on day 4. All animals were sacrificed and segments of the terminal ileum were stained with hematoxylin-eosin. Apoptosis of the epithelial cells was identified at the cellular level by the TUNEL stain and was distinguished from necrosis by the characteristic morphology of the cells (cytoplasmic shrinkage, marginal chromatin condensation and generation of nuclear apoptotic bodies). Apoptotic cells in the control animals were few and detected only at the tips of the villi while in the irradiated animals almost all the epithelial cells were apoptotic, distributed from the crypts to the tips of the villi and the mucosa showed severe epithelial atrophy and ulceration. The histologic picture of the mucosa in the GH and IGF-I treated animals was similar to normal controls and apoptotic cells were restricted only at the tips of the villi. DNA and RNA from the mucosa cells were isolated and analyzed by electrophoresis. DNA fragmentation and RNA 28s band ribonuclease cleavage was observed only in the irradiated animals. We have shown that abdominal radiation causes intestinal epithelial cell damage mainly through the induction of apoptosis and the treatment with GH and IGF-I inhibits apoptosis of the cells and preserves the mucosal integrity.

Beneficial effects of growth hormone and insulin-like growth factor I on intestinal bacterial translocation, endotoxemia, and apoptosis in experimentally jaundiced rats

BACKGROUND This study was undertaken to investigate the effect of growth hormone (GH) and insulin-like growth factor I (IGF-I), two well-known growth factors, on bacterial translocation, endotoxemia, enterocyte apoptosis, and intestinal and liver histology in a model of experimental obstructive jaundice in rats. STUDY DESIGN One hundred six male Wistar rats were divided into five groups: I (n = 21), controls; II (n = 22), sham operated; III (n = 22), bile duct ligation (BDL); IV (n = 21), BDL and GH treatment; and V (n = 20), BDL and IGF-I administration. By the end of the experiment, on day 10, blood bilirubin was determined, and mesenteric lymph nodes, liver specimens, and bile from the bile duct stump were cultured. Endotoxin was measured in portal and aortic blood. Tissue samples from the terminal ileum and liver were examined histologically and apoptotic body count (ABC) in intestinal mucosa was evaluated. Mucosal DNA and protein content were also determined. RESULTS Bilirubin increased significantly after BDL (p < 0.001). Bile from the bile duct was sterile. In group III, MLN and liver specimens were contaminated by gut origin bacteria (significant versus group I and II, p < 0.001, respectively). GH reduced significantly positive cultures (p < 0.01), and IGF-I had no effect. BDL resulted in significant increase in portal and aortic endotoxemia (p < 0.001); treatment with GH and IGF-I reduced it (p < 0.001). Mucosal DNA and protein content were reduced in animals with BDL and after treatment with GH or IGF-I; an increase to almost normal levels was noted in DNA, but not in protein. Overall the ileal architecture remained intact in all animal groups. The ABC increased after BDL. After GH and IGF-I administration, the ABC decreased significantly, and there was no difference between GH and IGF-I treated animals. After BDL, liver biopsies displayed typical changes of biliary obstruction, which were significantly improved after administration of GH and IGF-I. CONCLUSIONS Treatment with GH and IGF-I in rats with experimental obstructive jaundice reduces endotoxemia, and it improves liver histology. Apoptosis, in the intestinal epithelium, may serve as a morphologic marker of the ileal mucosal integrity, demonstrating the proliferative potential of GH and IGF-I in cases of obstructive jaundice, and this might be of potential value in patients with such conditions.

bcl-2/bax ratio as a predictive marker for therapeutic response to radiotherapy in patients with rectal cancer.

Combined radiation therapy and chemotherapy are adjuvant treatments given after surgery to patients with rectal carcinoma. Because apoptosis seems to play a role in tumor response to radiotherapy, the current study investigates whether there is a correlation between the ratio of bcl-2 oncoprotein and bax expression in rectal adenocarcinoma and the clinical response to radiotherapy. Elective colectomy for primary rectal adenocarcinoma followed by adjuvant radiotherapy and chemotherapy was performed on 35 patients. Tumors were staged as B 2 (n = 30) and C (n = 5), and were classified as radiation resistant (n = 19, group A) and radiation nonresistant (n = 16, group B). Immunohistochemical study, using the streptavidin-biotin complex technique and monoclonal antibody to bcl-2 and polyclonal antibody to bax protein was used on paraffin sections. Cases were considered positive if at least 5% of tumor cells displayed cytoplasmic staining for bcl-2 or bax. In each tumor, the bcl-2/bax ratio was calculated dividing the percentage of bcl-2–positive cells by the percentage of bax-positive cells. For statistical analysis, the Mann–Whitney rank sum test and Kruskal–Wallis analysis of variance test were used. Rectal tumors of group A displayed significantly greater bcl-2 immunoreactivity (40.2 ± 4.2) compared with group B (20.2 ± 3.8). In contrast, expression of bax protein was less in group A (30.3 ± 3.3) compared with group B (41.3 ± 2.3). The bcl-2/bax ratio was greater in group A (1.3 ± 0.1) compared with group B (0.49 ± 0.1), and was correlated with poor responsiveness to radiotherapy. The current study indicates that in patients with rectal carcinoma an elevated bcl-2/bax ratio in tissue specimens suggests increased tumor resistance to adjuvant radiotherapy. Thus, in such patients, the bcl-2/bax ratio may serve as a potential molecular marker for prediction of tumor prognosis.

Altered intestinal tight junctions’ expression in patients with liver cirrhosis: a pathogenetic mechanism of intestinal hyperpermeability

Eur J Clin Invest 2012; 42 (4): 439–446

Effect of Oral Glutamine Administration on Bacterial Tanslocation, Endotoxemia, Liver and Ileal Morphology, and Apoptosis in Rats with Obstructive Jaundice

Postoperative complications in patients with obstructive jaundice remain increased when associated with endotoxemia and the inflammatory response due to gut barrier failure. Administration of glutamine has been proposed to maintain the integrity of the gut mucosa and thus reduce bacterial translocation (BT), but the effects of this pretreatment on apoptosis and histologic morphology of various organs affected by BT in obstructive jaundice have not been studied. We therefore studied the effects of oral glutamine supplementation on endotoxemia, BT, liver and terminal ileal morphology, and apoptosis in an experimental model of obstructive jaundice. A total of 60 male Wistar rats were randomly divided into four groups of 15 each: I, controls; II, sham-operated; III, bile duct ligation (BDL); IV, BDL + glutamine (4.5 g/kg/day in drinking water). Ileal samples for histology, DNA and protein content, liver biopsies, mesenteric lymph nodes (MLNs) for culture, and portal and systemic blood samples for endotoxin measurements were obtained 10 days later. Compared to the controls, a significant increase in contaminated MLN and liver samples and increased endotoxemia were noted in group III (p < 0.01) but were significantly reduced in group IV (p < 0.05). Group IV also had a significantly higher number of mitoses per crypt (M/c) (p < 0.05), less apoptotic body counts (ABCs) (p < 0.05), and a higher DNA content than did group III (p < 0.05). Liver biopsies from group III displayed typical changes of large duct obstruction that significantly improved after glutamine treatment, with decreased ductular proliferation.We concluded that supplementation of oral glutamine in the presence of obstructive jaundice ameliorates BT, endotoxemia, and apoptosis and improves the ileal and liver histology.

Bombesin and neurotensin reduce endotoxemia, intestinal oxidative stress, and apoptosis in experimental obstructive jaundice.

Objective:To evaluate the effect of bombesin (BBS) and neurotensin (NT) on intestinal histopathology, intestinal oxidative stress, and endotoxemia in experimental obstructive jaundice. Summary Background Data:Obstructive jaundice compromises gut barrier function, resulting in endotoxemia. BBS and NT, exerting various biologic actions on gastrointestinal tissues, preserve gut mucosal integrity in cases of injury or atrophy. Methods:Seventy male Wistar rats were randomly divided into 5 groups: I = controls, II = sham operated, III = bile duct ligation (BDL), IV = BDL + BBS (30 μg/kg/d), V = BDL + NT (300 μg/kg/d). By the end of the experiment, on day 10, endotoxin was measured in portal and aortic blood. Tissue sections of the terminal ileum were examined histologically, and villus density, mucosal thickness, mitotic activity and apoptosis in crypts were assessed. In addition, ileal mucosa was analyzed for DNA and protein content. To estimate intestinal oxidant/antioxidant equilibrium, lipid peroxidation, protein oxidation, and thiol redox state (reduced glutathione [GSH], oxidized glutathione [GSSG], total nonprotein mixed disulfides [NPSSR], protein thiols [PSH], and protein disulfides [PSSP]) were determined on tissue homogenates from the terminal ileum. Results:BBS or NT administration significantly reduced portal and systemic endotoxemia observed in obstructive jaundice. Both factors reversed obstructive jaundice-induced morphologic features of intestinal atrophy, increasing villus density and mucosal thickness. This effect was accompanied by induction of mitoses and reduction of apoptosis in intestinal crypts. Mucosal DNA and protein content were reduced, although not to significant levels, in BDL animals and restored to control levels after BBS or NT treatment. Moreover, BBS or NT administration protected the intestine in jaundiced rats against oxidative stress, as demonstrated by reduction of intestinal lipid peroxidation, increase of the antioxidant GSH, and decrease of the oxidized forms GSSG and NPSSR, while BBS additionally reduced protein oxidation as well. Conclusions:Administration of BBS or NT in bile duct–ligated rats exerts beneficial effects on intestinal oxidative stress, cell proliferation, apoptosis, and endotoxemia. This observation might be of potential value in patients with extrahepatic cholestasis.

Evidence for intestinal oxidative stress in patients with obstructive jaundice

Background  Obstructive jaundice results in failure of the intestinal barrier with consequent systemic endotoxemia associated with septic complications. We have recently shown that gut barrier failure in experimental obstructive jaundice is associated with high intestinal oxidative stress. This study was undertaken to investigate whether oxidative alterations occur in the intestinal mucosa of patients with obstructive jaundice.

Tight junctions in thyroid carcinogenesis: diverse expression of claudin-1, claudin-4, claudin-7 and occludin in thyroid neoplasms

Claudins and occludin are integral constituents of tight junctions and are deregulated in a variety of malignancies. Their role in thyroid carcinogenesis has not yet been elucidated. This study investigates the expression of occludin and claudin-1, -4 and -7 in thyroid neoplasms. Ninety-one thyroid neoplasms (15 follicular adenomas, 15 follicular carcinomas, 26 papillary carcinomas, 16 papillary microcarcinomas, 8 medullary carcinomas, 3 poorly differentiated carcinomas, 8 undifferentiated carcinomas) were immunostained with antibodies against occludin and claudin-1, -4 and -7. Occludin was mainly expressed in the form of intracytoplasmic vesicles, whereas all claudins tested exhibited membranous immunostaining. Thirteen out of 15 follicular adenomas, 10/15 follicular carcinomas, 24/26 papillary carcinomas, 15/16 papillary microcarcinomas, 1/8 medullary carcinomas, 2/3 poorly differentiated carcinomas and 2/8 undifferentiated carcinomas exhibited claudin-1 expression, whereas claudin-4 was expressed in 13/15, 12/15, 23/26, 13/16, 7/8, 2/3 and 2/8 of the tumors, respectively, and claudin-7 expression was found in 67, 33, 73, 69, 25, 0 and 13% of the cases, respectively. Occludin was expressed in 100% follicular adenomas, 80% follicular carcinomas, 96% papillary carcinomas, 50% papillary microcarcinomas, 50% medullary carcinomas, 33% poorly differentiated carcinomas and 88% undifferentiated carcinomas. Occludin expression was reduced in papillary microcarcinomas, medullary carcinomas and poorly differentiated carcinomas. All claudins exhibited reduced expression in undifferentiated carcinomas. Claudin-1 was additionally reduced in medullary carcinomas and claudin-7 in follicular, medullary and poorly differentiated carcinomas. A correlation between loss of claudin-1 expression and worse disease-free survival was noted on univariate analysis. Dedifferentiation of the thyroid carcinomas is accompanied by reduction in claudin-1, -4 and -7 expression. A differential expression of tight junction proteins in the different histologic types of thyroid gland is noted. Additionally, claudin-1 expression may be an important prognostic indicator of recurrence in thyroid carcinomas.

Bacterial translocation, endotoxaemia and apoptosis following Pringle manoeuvre in rats ☆

BACKGROUND Intraoperative occlusion of the hepatoduodenal ligament (Pringle manoeuvre (Pm)) is often employed for the reduction of blood loss during liver surgery. No data exist to date on the effects of Pm on mucosal barrier dysfunction, systemic bacterial translocation (BT), endotoxaemia and apoptosis. MATERIALS AND METHODS Sixty-five male Wistar rats in three groups: I (n=25) controls, II (n=20) sham operation, III (n=20) occlusion of the hepatoduodenal ligament (Pm). Tissue samples from mesenteric lymph nodes (MLNs), liver, lungs and spleen were analysed after 30 min and at 24 h. Endotoxin was measured in portal and aortic blood and routine haematological and biochemical parameters were measured before and after Pm. RESULTS No differences were found in the blood parameters before and after Pm, but a significant increase in contaminated MLNs and liver was noted. All cultured bacteria were enteric in origin. Portal and aortic endotoxin were significantly increased. Overall the ileal architecture remained intact in all specimens studied and no significant pathology was observed. The ABC increased after Pm significantly (P<0.01). CONCLUSION Normothermic Pm of 30 min duration results in immediate and delayed gut barrier failure by significantly increasing BT and endotoxaemia which might be attributed to portal stasis leading to intestinal congestion as well as temporary liver ischaemia. Apoptosis increased significantly 30 min after performing the Pm.