enhancement of vasopressin and oxytocin secretion in rat neurohypophyseal tissue culture.

The effects of adrenaline (A) and noradrenaline (NA) on vasopressin (VP) secretion were studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP contents of the supernatant media were determined by radioimmunoassay after a 1 or 2-h incubation. Significantly increased VP levels were detected in the tissue culture media following the administration of A (an alpha + beta(2)-receptor agonist), depending on the dose of A. The VP secretion elevation was totally blocked by the previous administration of phentolamine (an alpha(1)+ alpha(2)-receptor antagonist) or corynanthine (an alpha(1)-receptor antagonist). Yohimbine (an alpha(2)-receptor antagonist) did not influence the VP secretion increase induced by A. After the administration of NA (a beta + alpha(1)-receptor agonist), a VP secretion elevation was again detected, but the degree of enhancement proved smaller than that of the VP secretion increase induced by A. Propranolol (alpha beta(1) + beta(2)-receptor antagonist) before NA administration prevented the VP secretion increase. Atenolol (a beta(1)-receptor antagonist) did not block the VP secretion elevation induced by NA. Corynanthine (an beta(1)-receptor antagonist) treatment before NA administration reduced the NA-induced VP enhancement, because NA has an alpha(1)-receptor agonist character in addition to its main character (a beta-receptor agonist). Surprisingly, the administration of pindolol (a beta(1) + beta(2)-receptor antagonist) enhanced VP secretion. This contradictory effect can be explained in that pindolol not only acts as a blocker, but also exerts "intrinsic sympathomimetic action" and a strong adrenergic agonist effect. Pindolol before NA administration significantly increased the NA-induced VP elevation.Conclusions: Mainly the alpha(1)- and beta(2)-adrenergic receptors are involved in the A- or NA-induced increase of VP secretion in isolated NH tissue cultures. The results indicate that VP release is influenced directly by the adrenergic system, and the adrenergic control of VP secretion from the NH tissue in rats can occur at the level of the posterior pituitary. (C) 2008 Elsevier B.V. All rights reserved.

Background: We investigated the involvement of myocardial tissue inducible and constitutive NOS (iNOS and cNOS) activities in the cardioprotective effect of early ischaemic preconditioning (IP) in closed-chest pigs subjected to percutaneous balloon coronary occlusion/reperfusion.Methods: Catheter-based 90-min occlusion followed by 60-min reperfusion of the left anterior descending coronary artery (LAD) was performed in 8 pigs (group AMI). IP was applied in 9 pigs (group IP) through 2 cycles of 5-min occlusion and 5-min reperfusion of the LAD before a 90-min occlusion and 60min reperfusion. Infarct size was expressed as a percentage of the area at risk. Fractional collateral flow reserve FFRcoll was measured with pressure-wire (PW) placed distally to the occluding balloon at IP, and during a 30-sec balloon occlusion of the infarkt related artery after final 60-min reperfusion. Tissue iNOS/cNOS activities were measured in the infarcted area (iNOS-I/cNOS-I) and in the border zone (iNOS-B/cNOS-B) by using of citrullin-assay.Results: Infarct size was smaller in group IP as compared with group AMI (21.7 +/- 4.4 vs 27 +/- 3.4 %; p = 0.014). IP did not influence the tissue iNOS-I, iNOS-B and cNOS-I activities neither in infarct, or border zone. A trend towards higher border zone cNOS-B activity (49.2 +/- 23.2 vs 31 +/- 25.1 pmol/min/mg protein; p = 0.142) was measured in group IP vs AMI. PW measurements distally to occlusion site revealed that IP led to higher FFR (coll) (0.18 +/- 0.06 vs 0.07 +/- 0.08; p = 0.031, IP vs AMI), even if it did not reach the value of 0.3 (index for sufficient collateralization). The FFR coll correlated significantly with cNOS-I (r = 0.726; p = 0.027) and cNOS-B (r = 0.832; p = 0.005) activities in group IP.Discussion: The beneficial effect of cNOS in ischaemia/reperfusion injury after IP results from the improved myocardial reperfusion after the release of coronary occlusion.

Background: The in-hospital mortality rate of non-variceal upper gastrointestinal bleeding (UGIB) is still considerable, and this figure seems to be remained stable during the past years. The aim of this retrospective study was to evaluate the risk-factors of in-hospital death due to non-variceal UGIB in this setting.

Background: Placement of self expanding metal stents (SEMS) has an emerging role to relieve acute colonic obstruction in otherwise operable colorectal cancer patients (pts). The aim of this retrospective study was to evaluate the efficacy and safety of colorectal SEMS insertion in pts with symptomatic malignant colonic obstruction.

Background. Endoscopic stent placement is considered as one of the best therapeutic option for palliation of patients (pts) with nonresecable hilar cholangiocarcinoma. At this date, there is no published study that provides detailed analyses of factors that has impact on survival of these pts palliated endoscopically. The aim of this retrospective study was to identify endoscopic and patient-related factors influencing the survival time of these pts.

Background: Endoscopic placement of self-expandable metal stents (SEMS) has proved to be the first line treatment option for palliation of patients (pts) with symptomatic cholestasis due to biliary strictures caused by nonresectable pancreato-biliary malignancies. However, at this date, there are small number of large-scale studies analyzing the safety and efficacy of placement of SEMS for palliation of malignant biliary strictures. The aim of this study was to evaluate retrospectively the long term technical and patient-related outcomes of cases where SEMS were used for management of malignant biliary strictures.

On 30 January 2000, a tailings pond burst at a facility near the city of Baia Mare, Romania which was reprocessing old mining tailings and re-depositing the waste sludge into a new tailings pond. This led to approximately 100,000 m 3 of waste water containing up to 120 tons of cyanide and heavy metals being released into the Lapus River, then traveling downstream into the Somes and Tisa rivers into Hungary before entering the Danube. The cyanide caused acute toxicity for different aquatic organisms (fish, phytoplankton, zooplankton, macrozoobenthos). On 10 March 2000, another tailings dam burst in Baia Borsa in the same region close to the Ukrainian border. While some of this material was retained within the dam complex, 20 thousand ton of sediments containing high concentration of lead, copper and zinc were then released into the Novat River, a tributary of the Viseu and Tisa rivers. The heavy metals were transported mainly in the suspended sediments along the Tisa River. In different sedimentation zones the settled polluted sediment increased the lead, copper and zinc concentration of the bottom sediment up to 1000 mg/kg order of magnitude. The above noted accidents revealed the lack of information on the potential pollution sources in the Tisa river basin. A relevant inventory of the potential pollution sources was compiled for the Tisa river basin after the above noted accidents.

Introduction: 5-amino salicylic acid (5-ASA) is successfully used in the treatment of inflammatory bowel disease (IBD). The better understanding of the mechanism of action of 5-ASA may lead further insight to the etiology of IBD. We know that oxidative stress plays a key role in causing inflammation. Thus, antioxidant enzyme systems have an important defensive function. The induction of the antioxidant systems, heme oxygenase-1 (HO-1) enzyme and glutathione (GSH) are involved in the maintenance of intestinal mucosal integrity.

Benign biliary strictures caused by bile duct injury and chronic pancreatitis usually respond sequential insertion of multiple plastic biliary stents. In some cases these stricture cannot be dilated with this method or after initial success the strictures may recur. If these patients unfit for surgery, insertion of self-expandable metal stents may be an alternative. However, there are few data concerning the safety and efficacy of SEMS for the treatment of benign biliary strictures.

The most frequent localisation of gastrointestinal stromal cell tumours (GIST) are the stomach, duodenum, the large bowel, however, there are reports on GIST of the oesophagus and the retroperitoneal space, too. The typical chronic clinical symptoms associated with GIST are abdominal pain, fullness, anaemia due to occult blood loss. Rarely these tumours can cause acute bleeding, obstruction and perforation of the GI tract.

Ulcerative colitis and Crohn's disease are both inflammatory bowel diseases. It has been shown that vascular infarctions play a role in the etiology of the severe transmural inflammation, characteristic of Crohn's disease. On the other hand, there is growing evidence that endogenous oestrogen is involved in the physiologic regulation of the vasodilator vascular tone. For the investigation of the mechanism of Crohn's disease, colonic injury following the local administration of 2,4,6-trinitrobenzene sulphonic acid (TNBS) is generally used.

BACKGROUND:A rare, late complication of endoscopic biliary sphincterotomy is the occurrence of short strictures extending from the papillary orifice to the distal parts of the extraduodenal common bile duct. METHODS:We evaluated the efficacy of the sequential insertion of multiple stents in the treatment of endoscopic biliary sphincterotomy associated common bile duct strictures. The design of the study is a prospective, single-arm observational study at a university-affiliated teaching hospital of 20 patients with distal common bile duct strictures because of choledocholithiasis-related endoscopic biliary sphincterotomy. Endoscopic treatment consisted of the sequential insertion of an increasing number of plastic stents with ever-larger diameters in 3-month follow-up intervals until stricture resolution. The primary outcome of the study was the rate of resolution of the stricture. The parameters measured were the duration of placement of stents, the maximum diameter, the total number of stents, and the total number of endoscopic sessions required for dilation of the strictures. RESULTS:After a median of 9.0 months of stent placement (range 3-22 months) and a median of 20F maximum stent diameter (range 10F-30F), 18 patients (90%) remained stent-free for a median of 14.5 months (range 6-38 months). Two patients (10%) had stricture recurrences at 10 and 24 months. Multivariate regression analysis demonstrated that the time elapsed after endoscopic biliary sphincterotomy was significantly associated with the stent-placement time (however, significance was removed by correction for multiple testing) and the number of ERCPs required for dilation. The initial common bile duct size was significantly associated with the total stent number and diameter needed for stricture resolution (however, significance was removed by correction for multiple testing). Limitations are the low case number and the single-arm, noncontrolled study design. CONCLUSIONS:Sequential insertion of an increasing number of biliary stents affords effective treatment of the distal biliary strictures that develop as a late complication of endoscopic biliary sphincterotomy.

Hemoxygenase-1 (HO-1) enzyme plays a protective role in the mechanism of inflammatory bowel disease. The expression of HO-1 can be induced by a number of agents, e.g. by heavy metals and hem (FePP). The mechanism of HO-1 induction is not fully understood, however, the involvement of glutathione (GSH) is suspected. AIM: We investigated the interaction of GSH with HO-1 expression in a human epithelial cell line (DLD-1). Methods: The expression of HO-1 and the GSH level were determined by Western Blot and by the DTNB method, respectively. Cells were treated with the GSH promoter, N-acetylcisteine (NAC; 10 mM)) or with the NF-kappaB inhibitor, MG 132. Results: Administration of FePP (50 micoM) or cadmium chloride (CdCl2; 10 microM) decreased GSH level within 10min. The maximum effect occurred after 1h, when baseline GSH level (23±0.5 nM/mg protein) reduced by 48% or 54% after FePP or CdCl2 administration, respectively. The expression of HO-1 developed 2h after incubation, when GSH level returned to the baseline value. Concurrent administration of NAC with FePP resulted in 45% decrease in GSH level, and an increase in HO-1 expression in a similar time-dependent manner as we found with FePP or CdCl2 alone. Administration of NAC inhibited FePP-provoked GSH level reduction, and delayed the expression of HO-1 over 4h. Administration of MG-132 (10 microM) did not affect FePP-evoked HO-1 induction. CONCLUSION: The reduction of GSH level following FePP and CdCl2 exposure is suggested to be involved in the induction of HO-1 in the human DLD-1 cell line. The present work was supported by The Hungarian Research Fund (OTKA F 42565).

Oesophageal cancer carries significant morbidity and mortality. The majority of patients can not be cured, thus require palliation. Endoscopic palliation of dysphagia can be achieved with bougienage, tumour ablation or placement of a stent. It has been shown that self-expandable metal stents (SEMS) are superior to plastic stents for palliation of malignant oesophageal strictures.