Chrisoula D. Scopa

Relative risk of cancer in sonographically detected thyroid nodules with calcifications.

The aim of this prospective study was to evaluate the significance of sonographically detected thyroid calcifications in the diagnosis of thyroid cancer.

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

Expression of the ribonucleases Drosha, Dicer, and Ago2 in colorectal carcinomas

The pathogenesis of colorectal carcinoma (CRC) is a complex process that involves the recruitment of both genetic and epigenetic mechanisms. Recent studies underline the cardinal role of small, noncoding RNA molecules, called microRNAs (miRs), in the pathobiology of numerous physiological and pathological processes, including oncogenesis. MiR biogenesis and maturation is mainly regulated by the nuclear ribonuclease Drosha and the cytoplasmic ribonucleases Dicer and Ago2. In the present study, we investigated the expression and distribution of these molecules in three colon cancer cell lines and in human CRC samples. Drosha, Dicer, and Ago2 mRNA and protein expression was assessed with real-time PCR, western blotting, and immunofluorescence. Our experiments showed that Drosha, Dicer, and Ago2 were expressed in all the cell lines and in the majority of the CRC samples examined. The mRNA levels of Dicer were significantly augmented in stage III compared to stage II tumors. Our results suggest that Drosha, Dicer, and Ago2 are possibly implicated in CRC pathobiology and that Dicer might have a role in the progression of these tumors to advanced stages.

Evaluation of Margin Status in Lumpectomy Specimens and Residual Breast Carcinoma

Abstract:  Residual disease leads to most local recurrences, especially in those patients treated with breast‐conserving therapy (BCT). This study evaluates whether assessment of excisional biopsy margins accurately predicts the presence or absence of residual tumor in the lumpectomy bed. The margin status of 201 consecutive lumpectomy specimens of 178 infiltrating and 23 in situ breast carcinomas followed by reexcision were evaluated microscopically and classified as “positive” (tumor at the inked margins), “negative” (tumor more than 0.1 cm from the inked margins), “close” (tumor within 0.1 cm of the inked margins, but not transecting it), and “indeterminate” (biopsy not inked or fragmented). Tumor size and grade were also analyzed, as potential predictors for residual disease. Residual tumor was found in 41% of the patients: in 21% of the cases with negative margins, in 63% with positive margins, in 30% with close margins, and in 56% with indeterminate margins. In 37% of the positive and 70% of the close margin cases, no tumor was found in reexcised specimens. In 24% of the cases the residual disease was composed entirely of an in situ component of the same histologic type as the initial biopsy. No relationship was found between tumor size or grade and residual disease. For breast tumors, histologically negative and “close” biopsy margins do not guarantee complete excision. A number of factors seem to be responsible for the discrepancy between the margin status and the presence/absence of residual cancer in the lumpectomy bed.

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.