Elias Kouroumalis

Potent inhibitory action of red wine polyphenols on human breast cancer cells.

Breast cancer (one of the most common malignancy in Western societies), as well as esophagus, stomach, lung, bladder, and prostate cancer, depend on environmental factors and diet for growth and evolution. Dietary micronutriments have been proposed as effective inhibitory agents for cancer initiation, progression, and incidence. Among them, polyphenols, present in different foods and beverages, have retained attention in recent years. Red wine is a rich source of polyphenols, and their antioxidant and tumor arresting effects have been demonstrated in different in vitro and in vivo systems. In the present study, we have measured the antiproliferative effect of red wine concentrate, its total polyphenolic pool, and purified catechin, epicatechin, quercetin, and resveratrol, which account for more than 70% of the total polyphenols in red wine, on the proliferation of hormone sensitive (MCF7, T47D) and resistant (MDA‐MB‐231) breast cancer cell lines. Our results indicate that polyphenols, at the picomolar or the nanomolar range, decrease cell proliferation in a dose‐ and a time‐dependant manner. In hormone sensitive cell lines, a specific interaction of each polyphenol with steroid receptors was observed, with IC50s lower than previously described. Interaction of polyphenols with steroid receptors cannot fully explain their inhibitory effect on cell proliferation. In addition, discrete antioxidant action on each cell line was detected under the same concentrations, both by modifying the toxic effect of H2O2, and the production of reactive oxygen species (ROS), after phorbol ester stimulation. Our results suggest that low concentrations of polyphenols, and consecutively, consumption of wine, or other polyphenol‐rich foods and beverages, could have a beneficial antiproliferative effect on breast cancer cell growth. J. Cell. Biochem. 78:429–441, 2000.

Treatment of hepatocellular carcinoma with octreotide: a randomised controlled study

Background—Standard treatment of inoperable hepatocellular carcinoma has not been established. Somatostatin has been shown to possess antimitotic activity against a variety of non-endocrine tumours. Aims—To assess the presence of somatostatin receptors in human liver and to treat advanced hepatocellular carcinoma with the somatostatin analogue, octreotide. Methods—Somatostatin receptors were measured in liver tissue homogenates from patients with acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Fifty eight patients with advanced hepatocellular carcinoma were randomised to receive either subcutaneous octreotide 250 μg twice daily, or no treatment. Groups were comparable with respect to age, sex, Okuda classification, presence of cirrhosis, and liver biochemistry and virology. Results—Various amounts of somatostatin receptors were identified in liver tissue of all patients including those with hepatocellular carcinoma. Treated patients had an increased median survival (13 months versus four months, p=0.002, log rank test) and an increased cumulative survival rate at six and 12 months (75% versus 37%, and 56% versus 13% respectively). Octreotide administration significantly reduced α fetoprotein levels at six months. When a multivariable Cox’s proportional hazards model was fitted, variables associated with increased survival were: treatment administration, absence of cirrhosis, increased serum albumin, and small tumours. Treated patients clearly had a lower hazard (0.383) in the multivariate analysis. Conclusions—Octreotide administration significantly improves survival and is a valuable alternative in the treatment of inoperable hepatocellular carcinoma.

Circulating levels of leptin, adiponectin, resistin, and ghrelin in inflammatory bowel disease

Background: There is evidence that adipocytokines play an important role in metabolism and in inflammation. Because human metabolism dramatically changes in inflammatory bowel disease (IBD) and chronic inflammation is the hallmark of the disease, we studied serum levels of leptin, adiponectin, resistin, and ghrelin in patients with ulcerative colitis (UC) and Crohns disease (CD) in comparison with healthy controls (HC). Methods: Leptin, adiponectin, resistin, and active ghrelin serum levels were measured in 100 IBD patients (46 UC and 54 CD) and in 60 matched HC using commercially available enzyme‐linked immunosorbent assays. Leptin, adiponectin, resistin, and ghrelin levels were correlated with disease activity, type, localization, and treatment. Results: Mean serum leptin levels were 10.6 ± 2.0 ng/mL in UC patients, 12.5 ± 2.6 ng/mL in CD patients, and 15.0 ± 1.8 ng/mL in HC (P = .01). Mean serum adiponectin levels were 9514.8 ± 787.8 ng/mL in UC patients, 7651.1 ± 613 ng/mL in CD patients, and 7270.6 ± 559.4 ng/mL in HC (P = .05). Mean serum resistin levels were 21.2 ± 2.2 ng/mL in UC patients, 18.7 ± 1.6 ng/mL in CD patients and 11.8 ± 0.6 ng/mL in HC (P = .0002). Mean serum ghrelin levels were 48.2 ± 4.2 pg/mL in UC patients, 49.4 ± 4.6 pg/mL in CD patients and 14.8 ± 3.0 pg/mL in HC (P < .0001). Serum levels of these adipocytokines were not correlated with either C‐reactive protein levels or the clinical indices of activity. No association between serum adipocytokines levels and disease localization in both UC and CD patients was found. Only serum ghrelin was significantly higher in ileal compared with colonic CD (P = .04). Conclusions: Serum levels of adiponectin, resistin, and active ghrelin are increased whereas serum levels of leptin are decreased in patients with IBD. Further studies are needed to elucidate the role of adipocytokines in IBD.

Wine antioxidant polyphenols inhibit the proliferation of human prostate cancer cell lines.

The effect of different wine antioxidant polyphenols (catechin, epicatechin, quercetin, and resveratrol) on the growth of three prostate cancer cell lines (LNCaP, PC3, and DU145) was investigated. A dose- and time-dependent inhibition of cell growth by polyphenols was found at nanomolar concentrations. The proliferation of LNCaP and PC3 cells was preferentially inhibited by flavonoids (catechin, epicatechin, and quercetin), whereas resveratrol was the most potent inhibitor of DU145 cell growth. Possible mechanisms of action were investigated: 1) The competition of polyphenols for androgen binding in LNCaP cells revealed significant interaction only in the case of high concentrations of quercetin, at least at five orders of magnitude higher than the concentrations needed for cell growth inhibition. All other phenols showed low interactions. 2) Oxygen species production after mitogen stimulation and H²O²2 sensitivity of these cell lines did not correlate with the observed antiproliferative effects, ruling out such a mode of action. 3) NO production revealed two different patterns: LNCaP and DU145 cells produced high concentrations of NO, whereas PC3 cells produced low concentrations. Phorbol ester stimulation of cells did not reveal any additional effect in LNCaP and DU145 cells, whereas it enhanced the secretion of NO in PC3 cells. Polyphenols decreased NO secretion. This effect correlates with their antiproliferative action and the inhibition of inducible NO synthase. It is therefore proposed that the antiproliferative effect of polyphenols is mediated through the modulation of NO production. In conclusion, our data show a direct inhibitory effect of low concentrations of antioxidant wine phenols on the proliferation of human prostate cancer cell lines mediated by the production of NO, further suggesting potential beneficial effects of wine and other phenol-containing foods or drinks for the control of prostate cancer cell growth.

Role of appendicitis and appendectomy in the pathogenesis of ulcerative colitis: a critical review.

Besides a genetic predisposition, a causal role of various environmental factors has been considered in the etiology of ulcerative colitis (UC). The association between appendectomy and UC has recently been the subject of intense scrutiny in the hope that it may lead to the identification of important pathogenetic mechanisms. Published data from animal models of colitis demonstrated reduction in experimental colitis after appendectomy, especially if performed at an early age. Several epidemiological case control and cohort studies have shown a strong and consistent relationship. The metaanalysis of 17 case-controlled studies showed an overall odds ratio 0.312 (95% confidence intervals = 0.261–0.373) in favor of appendectomy (p < 0.0001). One of the two recent large cohort studies is in agreement with these results, but the other failed to confirm them. All these studies have suggested that alterations in mucosal immune responses leading to appendicitis or resulting from appendectomy may negatively affect the pathogenetic mechanisms of UC. Further investigation of the role of appendectomy in UC is expected to open new fields for basic scientific research and may lead to the improvement of our understanding for the disease pathogenesis.

CC Chemokine Receptor 9 Expression Defines a Subset of Peripheral Blood Lymphocytes with Mucosal T Cell Phenotype and Th1 or T-Regulatory 1 Cytokine Profile

The chemokine receptor CCR9 is expressed on most small intestinal lamina propria and intraepithelial lymphocytes and on a small subset of peripheral blood lymphocytes. CCR9-expressing lymphocytes may play an important role in small bowel immunity and inflammation. We studied the phenotype and functional characteristics of CCR9+ lymphocytes in blood from normal donors. A subset of CCR9+ T cells have a phenotype of activated cells and constitutively express the costimulatory molecules CD40L and OX-40. In contrast to CCR9−, CCR9+CD4+ peripheral blood T cells proliferate to anti-CD3 or anti-CD2 stimulation and produce high levels of IFN-γ and IL-10. IL-10-producing cells were exclusively detected within the CCR9+ subset of CD4+ T cells by intracellular staining and were distinct from IL-2- and IFN-γ-producing cells. Moreover, memory CCR9+CD4+ lymphocytes respond to CD2 stimulation with proliferation and IFN-γ/IL-10 production, whereas memory CCR9−CD4+ cells were unresponsive. In addition, memory CCR9+CD4+ T cells support Ig production by cocultured CD19+ B cells in the absence of prior T cell activation or addition of exogenous cytokines. Our data show that the memory subset of circulating CCR9+CD4+ T cells has characteristics of mucosal T lymphocytes and contains cells with either Th1 or T-regulatory 1 cytokine profiles. Studies on the cytokine profile and Ag specificity of this cell subset could provide important insight into small intestinal immune-mediated diseases and oral tolerance in humans.

Role of angiogenesis in inflammatory bowel disease.

&NA; Several studies have shown alterations in vascular anatomy and physiology in inflammatory bowel disease (IBD). These findings, together with the observed upregulation of the mediators of angiogenesis in IBD patients, suggest that angiogenesis possibly contributes to the initiation and perpetuation of IBD. There is considerable evidence of an interrelationship between the mechanisms of angiogenesis and chronic inflammation in IBD. The increased expression of endothelial junction adhesion molecules found in IBD patients indicates the presence of active angiogenesis. Evidence that angiogenesis is involved in IBD was also obtained from animal models of colitis, most notably from studies of angiogenesis inhibition. Serum levels of vascular endothelial growth factor (VEGF) correlate with disease activity in human IBD and fall with the use of steroids, thalidomide, or infliximab. Pharmacological inhibition of angiogenesis, therefore, has the potential to be a therapeutic strategy in IBD. This review outlines the evidence that the rate of angiogenesis is increased in the inflamed intestine in IBD and proposes lines for future research in this field.

Anti–saccharomyces cerevisiae mannan antibodies and antineutrophil cytoplasmic autoantibodies in Greek patients with inflammatory bowel disease

OBJECTIVES:The combined measurement of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) and anti–Saccharomyces cerevisiae mannan antibodies (ASCA) has recently been suggested as a valuable diagnostic approach in inflammatory bowel disease (IBD). The aim of this study was to assess the value of detecting pANCA and ASCA in the differentiation between ulcerative colitis (UC) and Crohns disease (CD) in a Greek population with IBD.METHODS:Sera were collected from 157 patients with IBD (97 with UC, 56 with CD, and four with indeterminate colitis) and 150 healthy controls. Determination of pANCA was performed by a standard indirect immunofluorescence technique on ethanol-fixed granulocytes and ASCA by an ELISA assay.RESULTS:In patients with UC, sensitivity, specificity, positive predictive value, and negative predictive value of the pANCA test was 67%, 84%, 93%, and 46% respectively. These values did not change significantly when the combination of positive pANCA and negative ASCA was used. ASCA test in diagnosing CD yielded a sensitivity, specificity, positive predictive value, and negative predictive value of 39%, 89%, 54%, and 81%. The combination of pANCA negative and ASCA positive increased the positive predictive value to 77% and it was associated with small bowel disease.CONCLUSIONS:A positive pANCA test in Greek patients has a diagnostic value in confirming a diagnosis of UC. Measurement of pANCA and ASCA together has a rather limited value in the differential diagnosis between UC and CD but may be of help in studying disease heterogeneity.

Balthazar computed tomography severity index is superior to Ranson criteria and APACHE II and III scoring systems in predicting acute pancreatitis outcome.

Background and Goals Acute pancreatitis runs an unpredictable course. We prospectively analyzed the prognostic usefulness of four different scoring systems in separately assessing three variables; acute pancreatitis severity, development of organ failure and pancreatic necrosis. Study 78 patients with acute pancreatitis were studied prospectively. Data pertinent to scoring systems were recorded 24 hours (APACHE II and III scores), 48 hours (Ranson score) and 72 hours (Balthazar computed tomography severity index) after admission. Statistical analysis was performed by using receiver operating characteristic curves and by comparing likelihood ratios of positive test (LRPT) for all three outcome variables. Results 44 patients were classified as mild and 34 as severe pancreatitis. When we compared LRPT, only that for the Balthazar score (11.2157) was able to generate large and conclusive changes from pretest to post-test probability in acute pancreatitis severity prediction. LRPT were 2.4157 for Ranson, 4.0980 for APACHE II and 3.6670 for APACHE III score. The APACHE II and III scores and Ranson criteria performed slightly better than the Balthazar score in predicting organ failure (LRPT: 4.0667, 3.2892, 3.0362 and 1.7941 respectively), while when predicting pancreatic necrosis the APACHE II and III performed slightly better than the Ranson score (LRPT: 2.0769, 2.7500 and 1.7813 respectively). Conclusions In all outcome measures the APACHE scores generate small and of similar extent changes in probability. The Balthazar score is superior to other scoring systems in predicting acute pancreatitis severity and pancreatic necrosis. However the Ranson and APACHE scores perform slightly better with respect to organ failure prediction.

Resistance to activated protein C and low levels of free protein S in Greek patients with inflammatory bowel disease

OBJECTIVE:Patients with inflammatory bowel disease (IBD) frequently suffer from thromboembolic events. A recently identified mechanism for thrombophilia, the poor anticoagulant response to activated protein C, has been suggested as one of the leading risk factors for thrombosis. The aim of this study was to evaluate the frequency of thrombophilic abnormalities, including activated protein C-resistance (APCR), in Greek patients with ulcerative colitis (UC) and Crohns disease (CD).METHODS:Forty-eight patients with UC, 36 with CD, and 61 matched healthy controls (HC) were studied. Cases with presence of lupus anticoagulant, use of anticoagulants or heparin, and pregnancy were excluded. Disease activity in CD was evaluated by use of the Crohns Disease Activity Index (CDAI) score and in UC by the Truelove-Witts grading system. Plasma levels of protein C, free protein S, antithrombin III (AT-III), activated protein C resistance (APCR), and fibrinogen were determined in IBD patients, as well as in HC. All the cases and controls with abnormal APCR were further studied by genetic testing for the factor V Leiden mutation.RESULTS:Mean fibrinogen levels in UC and CD patients were significantly elevated (p < 0.0001), compared with HC. The mean values of free protein S, as well as mean APCR, were significantly lower in UC and CD patients than in the HC (p < 0.0001). Seven (five UC and two CD) of 84 IBD patients (8.3%) and three of the HC (4.9%) had the factor V Leiden mutation. No significant difference was observed for the other thrombophilic parameters. Fibrinogen levels and profound free protein S deficiency were found related to disease activity.CONCLUSIONS:Thrombophilic defects are common in Greek patients with IBD and they could interfere either in the disease manifestation or in the thrombotic complications.