Time progression and regional expression of brain oxidative stress induced by obstructive jaundice in rats.

BACKGROUND: Obstructive jaundice induces oxidative changes in the brain parenchyma and plays significant role in clinical manifestations of hepatic encephalopathy. We aim to study the progression of the brain oxidative status over time and the differences of its pattern over the hemispheres, the brainstem and the cerebellum. We use an experimental model in rats and measuring the oxidative stress (OS) specific biomarkers protein malondialdehyde (PrMDA) and protein carbonyls (PrC = O). RESULTS: Hyperbilirubinemia has been confirmed in all study groups as the result of common bile duct obstruction. We confirmed increase in both PrMDA and PrC = O biomarkers levels with different type of changes over time. We also confirmed that the oxidative process develops differently in each of the brain areas in study. CONCLUSIONS: The present study confirms the progressive increase in OS in all brain areas studied using markers indicative of cumulative protein modification.

Risk Factors for Surgical Site Infections in Patients Undergoing Emergency Surgery: A Single-centre Experience.

BACKGROUND/AIM: Surgical site infections (SSI) are associated with increased morbidity and mortality, and they occur more frequently during unplanned emergency surgical (ES) procedures rather than elective. Our aim was to determine the incidence of SSI within our ES cohort and to identify risk factors for SSI. PATIENTS AND METHODS: Data from consecutive patients undergoing ES in a single institution during a 5-year period were prospectively collected and analyzed. RESULTS: A total of 838 consecutive patients were included. The median age was 52 (IQR=25-71) years and some 368 (44%) were female. 157 (18.7%) of those patients developed SSI. The most commonly isolated pathogen was E. Coli (55.4%) followed by Staphylococcus Aureus (40.1%). The 30-day mortality rate of patients who presented SSIs was 14.6% compared to 6.8% of patients without SSI (p=0.002). Multivariable analysis showed that the type of wound, American Society of Anesthesiology score, severity and duration of surgery >90 min were independent risk factors for the occurrence of SSI. CONCLUSION: Identification of modifiable causative factors for SSI within an ES unit is paramount as they can critically impact postoperative outcomes.

Management of blunt hepatic and splenic injuries (grade ≤ III) in patients receiving antithrombotic therapy.

BACKGROUND: Non-operative management (NOM) may be particularly challenging in patients receiving synchronous antithrombotic therapy (AT). The current study examined the feasibility of NOM in patients under AT who sustained blunt splenic or hepatic injuries. METHODS: We analyzed the results of a 5-year (2010-2014) pre-decided treatment protocol, including 15 patients under AT who were treated for splenic and/or hepatic injuries at our institution. The antithrombotic therapy consisted of acenocoumarol 4 mg, acetylsalicylic acid 100 mg and clopidogrel 75 mg. Vitamin K (Vit K), Fresh frozen plasma (FFP) and Prothrombin Complex Concentrate (PCC) were transfused to patients receiving anticoagulant therapy, while platelets (PLTs) were given to patients under antiplatelet therapy if their level was excessively low. The organ injury grading scale, injury severity score (ISS), the need for blood transfusion and intensive care unit (ICU)/ high dependency unit (HDU) admission, morbidity, mortality and duration of hospital stay were also recorded. RESULTS: Ten patients fulfilled the criteria for NOM and were treated accordingly. No conversion to operative management (OM) was required (success rate 100%). Five patients were managed surgically due to hemodynamic instability and/or signs of peritonitis. Reversal of AT was attempted in all cases. CONCLUSIONS: Hemodynamically stable patients under AT with blunt hepatic or splenic injuries (grade ≤ III) and no signs of peritonitis, may be good candidates for NOM, despite their bleeding tendency. The type of AT does not seem to influence the final outcome. Reversal of AT should be stratified individually. KEY WORDS: Antithrombotic therapy, Hemodynamic stability, Non-operative management.

Successful non-operative management of blunt abdominal trauma in highly selective cases: A safe and effective choice.

BACKGROUND: The non-operative management (NOM) of abdominal injuries has gained wide acceptance over the last few decades. The present study evaluated the efficacy of NOM in blunt abdominal trauma (BAT) at a regional Hellenic hospital. METHODS: We analyzed the results of a pre-decided treatment protocol, which was applied to all patients hospitalized for BAT, from 2008 to 2015. The protocol proposed NOM in hemodynamically stable patients with no signs of peritonitis. The demographic characteristics, type of injury, injured organ(s), type of management (operative vs. non-operative), Injury Severity Score (ISS), morbidity, mortality rates, and health costs were evaluated. RESULTS: One hundred and forty-six patients hospitalized for BAT at our department were included. Among them, 49 were operated and 97 were subjected to NOM. Although ISS was significantly higher in the surgical group, the severity of injuries in liver, spleen, and kidneys was not different between the two groups. Surprisingly, no case subjected to NOM required a conversion to operative management, which may probably be because of the strict inclusion criteria for NOM. CONCLUSION: Patients with hemodynamic stability and normal physical examination may be non-operatively treated, independent of the grade of injury, in highly selective cases. ISS score is an independent risk factor for surgical treatment.

Screening for colorectal cancer: the role of the primary care physician.

In recent years, the role of primary care physicians (PCPs) in the diagnosis and management of gastrointestinal disorders, including screening for colorectal cancer (CRC), has been recognized as very important. The available data indicate that PCPs are not adequately following CRC screening guidelines because a number of factors have been identified as significant barriers to the proper application of CRC screening guidelines. These factors include lack of time, patient reluctance, and challenges related to scheduling colonoscopy. Further positive engagement of PCPs with CRC screening is required to overcome these barriers and reach acceptable levels in screening rates. To meet the expectations of modern medicine, PCPs should not only be able to recommend occult blood testing or colonoscopy but also, under certain conditions, able to perform colonoscopy. In this review, the authors aim to provide the current knowledge of the role of PCPs in increasing the rate and successfully implementing a screening program for CRC by applying the relevant international guidelines.

Colonoscopy in Colorectal Cancer Screening: Current Aspects.

Colonoscopy represents a very important diagnostic modality for screening for colorectal cancer, because it has the ability to both detect and effectively remove pro-malignant and malignant lesions. It is recommended by almost all international and national gastroenterology and cancer societies, as an initial screening modality or, following a positive fecal occult blood test, to be performed every 10 years in individuals of average risk starting from the age of 50. However, a significant problem is the so-called post-screening (interval) polyps and cancers found some years after the index colonoscopy. In order to reduce the rate of interval cancers it is extremely necessary to optimize the quality and effectiveness of colonoscopy. Bowel preparation is of paramount importance for both accurate diagnosis and subsequent treatment of lesions found on colonoscopy. The quality of bowel preparation could be significantly improved by splitting the dose regimens, a strategy that has been shown to be superior to single-dose regimen. A good endoscopic technique and optimal withdrawal time offering adequate time for inspection, would further optimize the rate of cecal intubation and the number of lesions detected. During the last years, sophisticated devices have been introduced that would further facilitate cecal intubation. The percentage of total colonoscopies is now super-passing the level of 95 % allowing the adenoma detection rate to be greater than the suggestive level of 25 % in men and 15 % in women. This review aims to provide the reader with the current knowledge concerning indications, usefulness, limitations and future perspectives of this probably most important screening technique for colorectal cancer available today.

Appendiceal mucocele and pseudomyxoma peritonei; the clinical boundaries of a subtle disease.

PATIENT: Male, 70 • Male, 84. FINAL DIAGNOSIS: Appendiceal mucocele and pseudomyxoma peritonei. SYMPTOMS: -. MEDICATION: -. CLINICAL PROCEDURE: -. SPECIALTY: Surgery. OBJECTIVE: Rare disease. BACKGROUND: Mucocele of the appendix is an uncommon cystic lesion characterized by distension of the appendiceal lumen with mucus. Most commonly, it is the result of epithelial proliferation, but it can also be caused by inflammation or obstruction of the appendix. When an underlying mucinous cystadenocarcinoma exists, spontaneous or iatrogenic rupture of the mucocele can lead to mucinous intraperitoneal ascites, a syndrome known as pseudomyxoma peritonei. CASE REPORT: We report 2 cases that represent the clinical extremities of this heterogeneous disease; an asymptomatic mucocele of the appendix in a 70-year-old female and a case of pseudomyxoma peritonei in an 84-year-old male. Subsequently, we review the current literature focusing to the optimal management of both conditions. CONCLUSIONS: Mucocele of the appendix is a rare disease, usually diagnosed on histopathologic examination of appendectomized specimens. Due to the existing potential for malignant transformation and pseudomyxoma peritonei caused by rupture of the mucocele, extensive preoperative evaluation and thorough intraoperative gastrointestinal and peritoneal examination is required.

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

BACKGROUND: Increased intestinal permeability in cirrhosis exerts a pivotal role in the pathogenesis of spontaneous bacterial peritonitis and other complications of cirrhosis through promotion of systemic endotoxemia. This study was designed to investigate whether the expression of tight junction (TJ) proteins, which regulate gut paracellular permeability, is altered in the intestinal mucosa of patients with liver cirrhosis and study its potential association with the stage of liver disease and the development of systemic endotoxemia. DESIGN: Twenty-four patients with cirrhosis at a decompensated (n = 12, group A) or compensated condition (n = 12, group B) and 12 healthy controls (group C) were subjected to duodenal biopsy. The expression of the TJ proteins occludin and claudin-1 in the intestinal epithelium was evaluated by immunohistochemistry. Plasma endotoxin concentrations were also determined. RESULTS: Patients with cirrhosis presented significantly higher serum endotoxin concentrations as compared to healthy controls (P < 0·001), whilst endotoxemia was higher in decompensated disease (P < 0·05 vs. compensated cirrhosis). Patients with decompensated and compensated cirrhosis presented significantly reduced expression of occludin and claudin-1 as compared to controls (P < 0·01, respectively). These alterations were significantly more pronounced in decompensated patients as compared to compensated (P < 0·05). Regarding occludin, in patients with cirrhosis, a specific pattern of expression in the intestinal epithelium was observed, with a gradually increasing loss of expression from crypt to tip of the villi. Occludin and claudin-1 expression were inversely correlated with Child-Pugh score (P < 0·001), the grade of oesophageal varices (P < 0·01) and endotoxin concentrations (P < 0·001). CONCLUSIONS: This study demonstrates for the first time that human liver cirrhosis induces significant alterations in enterocytes' TJs. These changes might represent an important cellular mechanism for intestinal barrier dysfunction and hyperpermeability in patients with liver cirrhosis.

Stimulation of oval cell and hepatocyte proliferation by exogenous bombesin and neurotensin in partially hepatectomized rats.

AIM: To investigate the effect of the neuropeptides bombesin (BBS) and neurotensin (NT) on oval cell proliferation in partially hepatectomized rats not pretreated with a known hepatocyte inhibitor. METHODS: Seventy male Wistar rats were randomly divided into five groups: I = controls, II = sham operated, III = partial hepatectomy 70% (PHx), IV = PHx + BBS (30 µg/kg per day), V = PHx + NT (300 µg/kg per day). Forty eight hours after liver resection, portal endotoxin levels and hepatic glutathione redox state were determined. α-fetoprotein (AFP) mRNA (in situ hybridisation), cytokeratin-19 and Ki67 antigen expression (immunohistochemistry) and apoptosis (TUNEL) were evaluated on liver tissue samples. Cells with morphological features of oval cells that were cytokeratin-19 (+) and AFP mRNA (+) were scored in morphometric analysis and their proliferation was recorded. In addition, the proliferation and apoptotic rates of hepatocytes were determined. RESULTS: In the control and sham operated groups, oval cells were significantly less compared to groups III, IV and V (P < 0.001). The neuropeptides BBS and NT significantly increased the proliferation of oval cells compared to group III (P < 0.001). In addition, BBS and NT induced a significant increase of hepatocyte proliferation (P < 0.001), whereas it decreased their apoptotic activity (P < 0.001) compared to group III. BBS and NT significantly decreased portal endotoxemia (P < 0.001) and increased the hepatic GSH: GSSG ratio (P < 0.05 and P < 0.001, respectively) compared to group III. CONCLUSION: BBS and NT stimulated oval cell proliferation in a model of liver regeneration, without use of concomitant suppression of hepatocyte proliferation as oval cell activation stimuli, and improved the hepatocyte regenerative response. This peptides-induced combined stimulation of oval cell and hepatocyte proliferation might serve as a possible treatment modality for several liver diseases.

Intestinal epithelial cell proliferation, apoptosis and expression of tight junction proteins in patients with obstructive jaundice.

BACKGROUND: Intestinal hyperpermeability has been repeatedly confirmed in patients with obstructive jaundice and is considered a pivotal factor in the development of septic and renal complications in these patients. However, little is known on the mechanism(s) leading to this phenomenon. This study was undertaken to investigate the cellular and subcellular intestinal alterations in patients with obstructive jaundice. DESIGN: Sixteen patients with obstructive jaundice of malignant (n = 8, group A) or benign (n = 8, group B) aetiology, without concomitant cholangitis, and eight healthy controls (group C) were subjected to duodenal biopsy distal to the ampulla of Vater. Specimens were examined histologically and the apoptotic activity in the cryptal epithelium was recorded. Epithelial proliferation was evaluated by immunohistochemical expression of Ki67 antigen. The expression of the tight junction (TJ) proteins occludin, claudin-1, claudin-4 and claudin-7 in the intestinal epithelium was also evaluated by immunohistochemistry. RESULTS: Patients with malignant or benign obstructive jaundice presented significantly decreased intestinal epithelial cell proliferation rates compared with controls (P < 0·05), whereas no differences were detected in apoptotic activity. In a semiquantitative analysis of TJ protein expression, occludin, claudin-1 and -7 were significantly decreased (P < 0·001), whereas claudin-4 was significantly increased (P < 0·01) in jaundiced patients and their distribution was altered. No differences were detected between patients with malignant or benign obstructive jaundice for all intestinal barrier parameters studied. CONCLUSION: Decreased enterocyte proliferation and altered TJ protein expression might represent important mechanisms for intestinal barrier dysfunction and hyperpermeability in patients with extrahepatic cholestasis. The potential pharmacological modulation of these factors may lead to better control of intestinal permeability in the jaundiced patient with improved clinical outcome.

Pilot implementation of a technologically advanced system for the optimization of pre-hospital, trauma patient care.

BACKGROUND: Cooperation between medical informatics, wireless communication and pre-hospital emergency services is essential for the optimal pre-hospital patient treatment. The use of technological innovations improves medical care in the pre-hospital setting with regard to the organization of an integrated center, which coordinates all parties involved for the patient's best interest. METHODS: A dispatch center was developed in the city of Patras, in southwestern Greece, equipped with a Geographic Information System (GIS), which immediately points out the location of emergency vehicles (EVs) on a digital map depicting the city plan. Additionally, three ambulances of the National Center of Immediate Aid (NCIA) were equipped with a decentralized traffic management system for the vehicle's traffic priority at signaled junctions. The system consisted of a cellular-based (GSM) telemedicine module, a Global Positioning System (GPS) and a web camera system in the vehicle cabin. RESULTS: The aforementioned system provided considerable assistance to the pre-hospital treatment first by selecting the ambulance closest to the accident's location and then by pinpointing the optimum route to the hospital, thus significantly reducing the overall transportation time. CONCLUSION: The project's objective to coordinate emergency hospital departments involved in the treatment of trauma patients with other emergency services by utilizing high technology was achieved within this interdisciplinary effort.

Bombesin and neurotensin exert antiproliferative effects on oval cells and augment the regenerative response of the cholestatic rat liver.

The regenerative capacity of the cholestatic liver is significantly attenuated. Oval cells are hepatic stem cells involved in liver's regeneration following diverse types of injury. The present study investigated the effect of the neuropeptides bombesin (BBS) and neurotensin (NT) on oval cell proliferation as well as on hepatocyte and cholangiocyte proliferation and apoptosis in the cholestatic rat liver. Seventy male Wistar rats were randomly divided into five groups: controls, sham operated, bile duct ligated (BDL), BDL+BBS (30 µg/kg/d), BDL+NT (300 µg/kg/d). Ten days later, alpha-fetoprotein (AFP) mRNA (in situ hybridization), cytokeratin-19 and Ki67 antigen expression (immunohistochemistry) and apoptosis (TUNEL) were evaluated on liver tissue samples. Cells with morphologic features of oval cells that were cytokeratin-19(+) and AFP mRNA(+) were scored in morphometric analysis and their proliferation was recorded. In addition, the proliferation and apoptotic rates of hepatocytes and cholangiocytes were determined. Alanine aminotransferase (ALT) levels and hepatic oxidative stress (lipid peroxidation and glutathione redox state) were also estimated. The neuropeptides BBS and NT significantly reduced ALT levels and hepatic oxidative stress. Both agents exerted similar and cell type-specific effects on oval cells, hepatocytes and cholangiocytes: (a) oval cell proliferation and accumulation in the cholestatic liver was attenuated, (b) hepatocyte proliferation was increased along with a decreased rate of their apoptosis and (c) cholangiocyte proliferation was attenuated and their apoptosis was increased. These observations might be of potential value in patients with extrahepatic cholestasis.

Bile leaks after cholecystectomy: the significance of patient selection.

OBJECTIVE: A retrospective analysis of laparoscopic and open cholecystectomies, with introduction of selection criteria and estimation of postoperative bile leaks. METHOD: All patients who underwent cholecystectomy in a tertiary surgical unit from January 2007 to June 2008 formed 2 categories, laparoscopic and open. The choice of operation was based on patient's present status and past medical history, whereas the decision to convert came from intraoperative findings. All surgeons were experienced in both open and laparoscopic surgeries. RESULTS: Laparoscopic cholecystectomy was initially attempted in 230 patients. In 218 of these patients, cholecystectomy was accomplished laparoscopically (group A), whereas in 12 laparoscopic was converted to open cholecystectomy (group B). In 36 patients open cholecystectomy was the first choice according to predecided criteria (group C). Patients of groups B and C were older (P=0.0001), presented higher incidence of cholecystitis (P=0.0001), and required longer postoperative hospitalization (P=0.0001) compared with patients of group A. Postoperative bile leak was evident in 8 patients; no patient from group A, 2 patients from group B, and 6 patients from group C. Patients with bile leak were older (P=0.0001), they required a longer hospitalization (P=0.0001), and cholecystitis was more frequent (P=0.007). Regarding treatment followed, 4 patients required no intervention, whereas 1 required computed tomography-guided drainage of a biloma. Two patients with persistent bile leak, required stenting of the common bile duct with endoscopic sphincterotomy, whereas one, suffering from common bile duct injury, was cured with hepatojejunostomy. CONCLUSIONS: The study highlights the significance of patient selection based on clinical criteria with respect to the type of operation performed. It seems that when patients are selected for laparoscopy according to carefully chosen criteria, the expected postoperative bile leaks could be minimal.

Cavernous hemangioma of infrahyoid carotid sheath and review of the literature on carotid sheath tumors.

BACKGROUND: Carotid sheath may include a variety of lesions such as neurogenic or vascular, tumors originating from extra-adrenal chromaphil cells, squamous cell carcinomas, and lymphomas. Hemangiomas are benign congenital neoplasms, which, when located in the head and neck region, may be easily misdiagnosed due to their infrequent localization. METHODS AND RESULTS: We report an unusual case of cavernous hemangioma of the infrahyoid carotid sheath presenting as palpable mass in a 51-year-old woman with no prior medical history. A review of the literature was performed to investigate the radiological and histopathological characteristics and highlight the treatment of carotid sheath lesions. CONCLUSIONS: CT, MRI, and MR angiography would help to locate hemangiomas of carotid sheath, but only surgical excision and histopathology can reveal their true nature.

Ancient schwannoma of lumbar spine and review of the literature on paraspinal tumors, the role of preoperative biopsy: a case report.

INTRODUCTION: Schwannomas are rare encapsulated tumors that derive from the nerve sheath and should be removed due to their infrequent, but existent possibility of malignancy. CASE PRESENTATION: We report a case of a mass located in the L5 lumbar spine in a 42 year old man, presented with intermittent lumbar pain. Ultrasound, CT and MRI were used to examine the characteristics of the lesion. Fine needle aspiration showed cytologic characteristics of benign schwannoma and final histological diagnosis was ancient schwannoma. An extraperitoneal approach, through a left paramedian incision was used to approach the site of the mass. The lesion originated from the nerve root of the L4-L5 lumbar spinal space and a complete excision was achieved. CONCLUSION: A great variety of tumors should be differentiated when a paraspinal mass is discovered, including neurogenic, neuroendocrine and vascular tumors, as well as malignancies, cystic and inflammatory masses. Fine needle aspiration is a useful and reliable tool in the preoperative evaluation of paraspinal masses. A review of the literature is also presented.

Bile duct ligation in rats: a reliable model of hepatorenal syndrome?

The two most widely used experimental models of advanced liver disease are the administration of carbon tetrachloride, and common bile duct ligation (BDL), however, neither has been systematically evaluated as a model of hepatorenal syndrome (HRS). The BDL model in rats, studied at diverse time points, induced a progressive renal dysfunction without structural changes in the kidney. The authors concluded that BDL is a good model for further studies of HRS and its treatment. However, the renal impairment observed at the acute phase of the BDL model is based on a different pathophysiology than that of HRS. Specifically, in acute obstructive jaundice, cholemia predominates over parenchymal liver disease (reversible at this stage without portal hypertension or cirrhosis) and independently induces negative inotropic and chronotropic effects on the heart, impaired sympathetic vasoconstriction response and profound natriuresis and diuresis that might lead to volume depletion. In addition, systemic endotoxemia contributes to the prerenal etiology of renal impairment and promotes direct nephrotoxicity and acute tubular necrosis. On the other hand, the renal failure observed in the chronic BDL model (with development of biliary cirrhosis, portal hypertension and ascites) shares pathophysiological similarities with HRS, but the accordance of the chronic BDL model to the diagnostic criteria of HRS (e.g. absence of spontaneous bacterial peritonitis, no renal function improvement after plasma volume expansion) should have been confirmed. In conclusion, we think that the BDL model is not suitable for the study of the natural history of HRS, but the chronic BDL model might be valid for the study of established HRS and its potential therapies.

Plasma superoxide radical in jaundiced patients and role of xanthine oxidase.

BACKGROUND: In the experimental setting, obstructive jaundice induces oxidative stress in several extrahepatic tissues (systemic phenomenon), which is at least partly attributed to activation of the enzyme xathine oxidase. Very little is known on this important issue in patients with cholestasis. The present study was designed to (a) assess directly oxidative stress in the blood of patients with obstructive jaundice by measuring superoxide radical, and (b) investigate ex vivo whether xanthine oxidase (XO) is the source of this radical. METHODS: Twelve patients with malignant obstructive jaundice and no signs of cholangitis, 12 nonjaundiced disease-controls with a localized gastrointestinal malignancy, and 12 healthy-controls were enrolled in the study. Superoxide radical levels were measured in the whole blood (plasma and cells) and in plasma previously separated. These measurements were also done in blood samples in the presence of the specific XO inhibitor allopurinol. RESULTS: Superoxide radical levels were significantly increased in the plasma fraction of whole blood in jaundiced patients when compared with disease-controls (P < 0.001) and healthy-controls (P < 0.001), whereas disease-control patients presented significantly increased superoxide radical levels when compared with healthy-controls (P < 0.001). No differences in superoxide radical levels in the blood cells were detected between jaundiced patients and disease-controls. In jaundiced patients, superoxide radical levels in the plasma fraction of whole blood were positively correlated with the degree of cholestasis. The addition of allopurinol to whole blood samples decreased superoxide radical in the plasma fraction of jaundiced patients to the disease-control level (P < 0.001), whereas it had no effect on superoxide radical levels in the cell fraction. No superoxide radical was detected in fractionated plasma in all cases. CONCLUSIONS: These data show that increased superoxide radical in the plasma of jaundiced patients is possibly formed from a source in the cytoplasmic membrane of blood cells and secreted into plasma. The reversal of this phenomenon by allopurinol, ex vivo, indicates that a blood cell membranous XO might be the source of increased plasma superoxide radical in patients with extrahepatic cholestasis.

Differential expression of dysadherin in papillary thyroid carcinoma and microcarcinoma: correlation with E-cadherin.

Dysadherin is a novel glycoprotein, with an anti-cell-cell adhesion function. The aim of the present study was to examine the expression of dysadherin in thyroid papillary microcarcinoma (PMC), to associate it with the expression of E-cadherin and to investigate whether there are differences with papillary carcinoma (PC). A statistically significant difference in dysadherin and E-cadherin expression between PC and PMC and a negative correlation between E-cadherin and dysadherin expression regardless of tumor size were noted. Based on these findings it is hypothesized that retained cell-cell adhesion, through maintenance of the E-cadherin adhesion system, in PMC prevents neoplastic cells from dissociating easily from each other and metastasizing. Increased dysadherin expression is possibly one of the post-transcriptional mechanisms responsible for E-cadherin downregulation in thyroid papillary neoplasia.

Superoxide radical formation in diverse organs of rats with experimentally induced obstructive jaundice.

Oxidative stress seems to be a cardinal feature of cholestasis, implicated in the pathophysiology of organ injury not only in the liver, but also in several extrahepatic tissues. The present study was designed to assess directly oxidative stress in vital organs of experimentally jaundiced rats by measuring the key oxidative stress marker superoxide radical (O2(*-)). Twelve male Wistar rats underwent laparotomy and were divided into two groups - group I (n = 6) sham operated, and group II (n = 6) bile-duct ligated. Ten days later, the O2(*-) formation rate was quantified in liver, intestine, kidney and heart of all animals. These measurements were done by application of a new ultrasensitive fluorescent assay for the in vivo quantification of O2(*-), which is based on the 1:1 molar stoichiometric reaction of O2(*-) with dihydroethidine (DHE, an O2(*-) trap) that results in the formation of the specific product 2-OH-ethidium. 2-OH-Ethidium was measured by fluorescence in rats' organs and its formation rate was converted to O2(*-) production rate. As compared to sham-operated rats, in jaundiced rats there was a significant increase of O2(*-) in the intestine (136%, P < 0.01), liver (104%, P < 0.01), and kidney (95%, P < 0.01), whereas there was no significant difference in heart O2(*-) levels. Superoxide radical may play an important role in the pathophysiology of cholestatic liver injury, intestinal barrier failure and renal failure, associated with postoperative morbidity and mortality in obstructive jaundice. On the contrary, O2(*-) and oxidative stress are possibly not implicated in the pathophysiology of hepatic cardiomyopathy.