Liver radiofrequency ablation compromises the biological gut barrier.

AIM: Liver radiofrequency ablation (RFA) has been shown to disrupt the mechanical component of the gut barrier. The aim of the present study was to investigate the consequences of liver RFA on the biological gut barrier in terms of the effects of bile production rate and bowel inflammatory state on intestinal microflora balance. METHOD: A total of 25 New Zealand rabbits were assigned to five groups (n = 5 per group): group CBD: subjected to common bile duct (CBD) extracorporeal bypass; group CBD-RFA: subjected to CBD bypass plus one session of open liver RFA; group RFA: subjected to liver RFA; group sham: subjected to sham operation; and group TBD: subjected to total bile deviation (TBD). In groups CBD and CBD-RFA, bile production rate was assessed for 48 h. In groups sham and RFA, measurement of biliary glycine conjugates of cholic and deoxycholic acid levels, histopathologic examination of the non-ablated liver tissue, morphometric analysis, and histopathologic examination of the terminal ileum and microbiological analysis of fecal and tissue samples collected from the jejunum and the cecum (and in group TBD) were performed at 48 h post-operation. RESULTS: One session of liver RFA resulted in ablation of 18.7 ± 2.7% of liver weight. Following liver RFA, bile production rate was reduced, while the levels of biliary bile salts were not affected. There was mild injury of the non-ablated liver parenchyma, mild intestinal wall inflammation, intestinal mucosa atrophy, and intestinal microbial population overgrowth. CONCLUSION: Reduced in bile production and mild bowel inflammation secondary to liver RFA impaired the biological gut barrier as manifested by intestinal microflora imbalance.

Restoration of hepatocytes function following decompression therapy in extrahepatic biliary obstructed patients: metabolite profiling of bile by NMR.

Prolonged biliary obstruction and infection cause retention of biliary constituents in liver followed by hepatocyte dysfunction. Decompression therapy is important for both management and prognostic reasons and restores hepatocyte function. Quantitative metabolite profiling of bile using NMR spectroscopy at the time of obstruction and serially following decompression therapy using percutaneous transhepatic biliary drainage (PTBD) from nineteen patients with extrahepatic malignant biliary obstruction are presented. Based on detailed history, clinical condition, total leucocyte counts (TLC) and microbiological cultures of bile, patients were classified in two groups depending upon absence or presence of cholangitis. Statistical analysis was performed for comparison within each group using Wilcoxan sign square rank test. TLC and liver function tests indicated a trend towards recovery following decompression by one week. While on day 0 biliary constituents were undetectable in both the groups of patients, they increased significantly following one week of drainage with better recovery in patients with cholangitis compared to without. Free amino acids' signals were detected in all specimens starting from day 1 after decompression. This indicates disruption of blood-bile barrier during cholestasis and slow restoration of tight junction of hepatocytes following decompression leading to the appearance of biliary constituents in bile. Decompression therapy tends to restore biliary constituents with a prompt recovery in patients with cholangitis further supports such therapy for clinical management and outcome. To our knowledge this is the first report on the detection of amino acids in bile taken from common bile duct though they have been reported in hepatic bile.

Disseminated histoplasmosis presenting with biliary obstruction and duodenal ulcer.

Disseminated histoplasmosis is an AIDS-defining illness which usually involves the liver and gastrointestinal tract, most commonly the small bowel. Abdominal pain, diarrhea, GI bleeding, hepatosplenomegaly and small bowel obstruction are well described presentations. Still gastrointestinal histoplasmosis often results in either vague symptomatology or no symptoms. Pancreaticobiliary disease related to disseminated histoplasmosis is not well characterized. We report the case of a young female with advanced HIV infection and biliary obstruction and a periampullary duodenal ulcer due to disseminated histoplasmosis.

The effect of caffeic acid phenethyl ester on bacterial translocation and intestinal damage in cholestatic rats.

We investigated the effect of caffeic acid phenethyl ester in rat ileum injury induced by chronic biliary obstruction. Swiss albino rats were divided into three groups: Group 1, sham (n = 7); Group 2, common bile duct ligation (n = 7); and Group 3, common bile duct ligation plus caffeic acid phenethyl ester (n = 7). In the caffeic acid phenethyl ester-treated rats, ileum tissue levels of malondialdehyde and myeloperoxidase were significantly lower than those of the bile duct-ligated rats (P < 0.001). The levels of tumor necrosis factor-alpha, interleukin-6, and interleukin-1alpha in the caffeic acid phenethyl ester group were significantly lower than those in the bile duct ligation group (P < 0.03, P < 0.01, and P < 0.02 respectively). The present study demonstrates that intraperitoneal administration of caffeic acid phenethyl ester in bile duct-ligated rats reduces intestinal oxidative stress. This effect may be useful in the preservation of intestinal damage in cholestasis.

Toll-like receptors 2 and 4 are differentially involved in Fas dependent apoptosis in Peyer's patch and the liver at an early stage after bile duct ligation in mice.

BACKGROUND AND AIMS: Surgical management of extrahepatic cholestasis is frequently complicated by bacterial translocation and severe liver injury. The aim of this study was to clarify the involvement of Toll-like receptors (TLRs) in the pathogenesis of bacterial translocation and liver injury in obstructive cholestasis. METHODS: TLR2 deficient (TLR2(-/-)), MyD88(-/-), Jalpha281(-/-), gld/gld, and lpr/lpr mice, all of which have a C57BL/6 background, and C3H/HeN and TLR4 mutated C3H/HeJ mice were subjected to bile duct ligation (BDL). Faecal IgA and serum alanine aminotransferase levels were determined after BDL. Apoptosis was examined by histological and flow cytometric analyses of cells from Peyer's patches and the liver. RESULTS: The size and number of B cells in Peyer's patches markedly decreased on day 3 after BDL. Increased apoptosis in Peyer's patch B cells was evident on day 1 after BDL in control mice but not in lpr/lpr, MyD88(-/-), or C3H/HeJ mice. On the other hand, TLR2 and Fas ligand expression on intrahepatic NK1.1(+) T cells increased on day 1 after BDL in C57BL/6 mice. Liver injury and apoptosis were evident on day 1 after BDL in control and C3H/HeJ mice but were significantly reduced in TLR2(-/-), Jalpha281(-/-), gld/gld, and lpr/lpr mice. CONCLUSIONS: TLR4 and TLR2 may play important roles in Fas dependent apoptosis in Peyer's patch B cells and hepatocytes, respectively, at an early stage after BDL in mice.

Glutamine improves intestinal barrier function in experimental biliary obstruction.

OBJECTIVE: To determine the effects of enteral administration of glutamine on intestinal barrier function in experimental biliary obstruction. BACKGROUND: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of multiple organs. The amino acid glutamine has been shown to improve intestinal barrier function in other conditions, but its effects in biliary obstruction have not been fully examined. METHODS: This study examined the effects of enteral administration of glutamine on intestinal permeability and on bacterial translocation from the intestine in a rodent model of biliary obstruction. RESULTS: Glutamine was shown to reduce intestinal permeability measured as percentage excretion of 14C 7 days after biliary obstruction (0.35+/-0.03 vs. 0.56+/-0.085% in controls, p=0.028), and glutamine administration was also associated with a decreased incidence of bacterial translocation to extra-intestinal sites (p=0.03). Radiolabelled bacterial studies also demonstrated reduced translocation of bacterial fragments to extra-intestinal sites in glutamine-treated animals (p=0.01). There was also some evidence of decreased exposure to endotoxin, reduced systemic inflammation and increased bacterial killing by the immune system in glutamine-treated animals. CONCLUSIONS: Glutamine modulates intestinal permeability and reduces bacterial translocation in an animal model of experimental biliary obstruction and may increase bacterial killing by the immune system.

The effect of immunonutrition on bacterial translocation, and intestinal villus atrophy in experimental obstructive jaundice.

BACKGROUND & AIMS: Spontaneous bacterial infection and septicemia due to increased bacterial translocation (BT) in patients with obstructive jaundice result in significant morbidity and mortality. The present study evaluates the effects of enteral nutrition with immune enhancing feeds on BT and intestinal villus histopathology promoted by obstructive jaundice. METHODS: Fifty male Wistar-albino rats weighing 250-300g were assigned into five equal groups of 10. Animals in Groups I, II, and III were fed with standard chow, those in Group IV were given glutamine 1g/kg/day and the remaining 10 animals in Group V were fed with an arginine, omega-3 fatty acids, and RNA-supplemented enteral diet for (1g/kg/day amino acid and 230 kcal/kg) 7 days preoperatively. Group I underwent sham operation and the remaining animals in all other groups underwent common bile duct ligation. After operation, Group I had standard chow, Groups II and IV had glutamine, Groups III and V had an arginine omega-3 fatty acids, and RNA-supplemented enteral diet for 7 days. All animals were sacrificed on the 8th postoperative day and evaluated both biochemically and histopathologically. Samples from blood, liver, mesenteric lymph nodes and spleen were cultured under aerobic conditions. RESULTS: Significantly less BT was observed in groups fed with an arginine, omega-3 fatty acids, and RNA-supplemented enteral diet or glutamine in pre-and postoperative periods as compared to others (P<0.001). Histologic evaluation also showed significant reduction in villus atrophy in these groups. CONCLUSIONS: Enteral immunonutrition using glutamine or arginine, omega-3 fatty acids, and RNA-supplemented enteral diet during both pre-and postoperative periods seems to reduce BT and decrease atrophy of intestinal mucosal villi in rats with obstructive jaundice.

Helicobacter species are not detectable by 16S rDNA PCR in bile from Dutch patients with common bile duct stones.

BACKGROUND: Some Helicobacter species colonize the intestinal tract. To explore the possible relation between Helicobacter spp. and gallbladder disorders, we have investigated their presence in bile of patients with biliary obstruction and dilatation of the bile ducts. METHODS: Bile was sampled from 31 Dutch patients with biliary obstruction identified by jaundice and dilatation of the bile ducts on ultrasound. Samples (n = 31) were obtained immediately following cannulation of the common bile duct (CBD) by endoscopic retrograde cholangiopancreatography (ERCP) (n = 29) or by peri-operative puncture of the gallbladder (n = 2). DNA was isolated from bile by binding to diatoms. Helicobacter spp. were detected by a sensitive (detection limit 1 CFU per reaction tube) 16S rDNA PCR with genus-specific primers. Duplicate samples were spiked with Helicobacter pylori DNA and subjected to PCR in order to check for inhibition. RESULTS: 28 patients had CBD stones (bile collected by ERCP (n = 26) or operatively (n = 2)), 2 had a pancreatic head tumor, and in 1 no abnormalities were found. In 1 of 21 amplifiable bile samples (10/31 inhibited) from Dutch patients with CBD stones, H. pylori 16S rDNA was found. CONCLUSION: Our data indicate that CBD stones in Dutch patients are not associated with the presence of Helicobacter spp. in bile.

Technical considerations to maintain a low frequency of postoperative biliary stent-associated infections.

BACKGROUND/PURPOSE: In patients with malignant biliary obstruction, preoperative biliary tract manipulation and stent drainage has been associated with increased infectious complications and mortality. METHODS: Between October 1996 and September 2000, 36 patients underwent bilioenteric anastomosis by a single surgeon. Diagnoses included pancreatic and other periampullary cancers (67%), benign obstruction (14%), hilar cholangiocarcinoma (8%), and other malignancies (11%). Preoperative bile duct manipulation had been done in 72%, and a biliary stent had been placed in 58%. Two-thirds of patients underwent major resection and the remainder were treated with internal biliary bypass. All patients had received preoperative bowel cleansing and perioperative antibiotics. Bile ducts were left clamped after incision until anastomotic completion to avoid biliary spillage, and drains were generally not placed. RESULTS: Intraoperative bile cultures were positive in 73%. This was strongly linked to the presence of a stent ( P = 0.0004), or prior duct manipulation ( P = 0.002). There were 3 postoperative, unrelated deaths in patients after palliative bypass (overall mortality rate, 8.3%). Postoperative infections occurred in 7 patients (19%), of which three were due to a similar organism. There was one biliary leak, no pancreatic leak, and no intraabdominal abscess. CONCLUSIONS: Appropriate preoperative antibiotic coverage, preventing intraoperative peritoneal bile contamination through temporary bile duct occlusion, and avoiding routine drain placement, are strongly suggested for patients in whom preoperative biliary manipulation has taken place.

[Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance]. / Interventionelle ERCP bei Patienten mit Cholestase: Häufigkeit und Antibiotikaresistenz der biliären Keimbesiedlung.

Interventional ERCP in patients with cholestasis. Degree of biliary bacterial colonization and antibiotic resistance. Biliary obstruction together with bacterial colonization of the bile duct may lead to development of acute cholangitis. The aim of our prospective study was to investigate the presence and degree of biliary bacterial colonization by means of bile aspiration during ERCP in patients with biliary obstruction. Furthermore, we evaluated antibiotic therapy regimens, which would cover the bacterial species obtained by ERCP and subsequent culture in each patient. In addition, analysis of risk factors was performed that would predispose to the development of cholangitis.80 patients with clinical and laboratory evidence of biliary obstruction underwent ERCP with initial aspiration of bile via the cannulation catheter. This material was used to culture aerobic and anaerobic bacteria and determine the colony count/ml bile, followed by identification of each species and antibiotic resistance testing. The minimal inhibitory concentration for Levofloxacin, Ciprofloxacin, Piperacillin, Ampicillin, Ceftriaxone, Imipenem, Gentamycin und Metronidazole was determined. Immediately after the ERCP or if the body temperature (after ERCP) rose to > 38 degrees C blood cultures were obtained. In 45 (56 %) patients biliary colonization with bacteria could be identified (56 %). In 20 patients a single isolate was cultured, in 25 cases mixed infection was present. A total of 83 species were isolated. The most common bacteria were E. coli, Enterococcus and Klebsiella. 9.6 % of all isolates were obligatory anaerobes. In 9 of 80 patients bloodcultures tested positive for bacterial growth (rate of bacteremia: 11.3 %). 10 patients had acute cholangitis clinically before ERCP, 13 patients developed signs of infection after ERCP. Statistically significant factors contributing to the risk of infection were age of the patient, the clinical condition of the patient before ERCP and the biliary colony count. Patients with development of infection after ERCP showed a significantly higher incidence of bacterial colonization of the biliary tree and a higher colony count. In all bacterial species Imipenem (4.5 %) or Levofloxacin (2.2 %) exhibited the lowest rate of in-vitro resistance. Based on these data, the implementation of Levofloxacin in combination with anaerobic coverage is advantageous as a calculated therapy for patients with acute cholangitis.

Changes in gastrointestinal morphology associated with obstructive jaundice.

Bacterial translocation has been consistently demonstrated in experimental models of obstructive jaundice. An important factor which promotes this phenomenon is physical injury of the intestinal mucosa. Some previous studies have presented suggestive evidence of this, following bile duct ligation. The aims of this study were to analyse objectively intestinal mucosal morphometric characteristics, to examine for evidence of bacterial translocation, and to assess enterocytes for ultrastructural abnormalities. Adult female Wistar rats were assigned to one of three groups: control (n=8), bile duct ligation (BDL; n=11), or sham operation (n=10). One week later, portal blood, mesenteric lymph nodes, liver, and spleen were harvested and cultured aerobically and anaerobically for evidence of bacterial translocation. Segments of jejunum, ileum, caecum, and large bowel were examined histologically, using light microscopy and morphometrically, using an image analysis system. Electron microscopy was performed on regions of the gastrointestinal tract where significant morphometric alterations had been identified. Significant bacterial translocation was identified following BDL (63. 6% BDL vs. 0% sham vs. 0% control, p<0.01, Fisher's exact test). There was a significant reduction in total mucosal thickness (standard error) [650 microm (23) BDL vs. 731 microm (27) sham vs. 744 microm (95) control] and villous height [451 microm (20) BDL vs. 515 microm (18) sham vs. 559 microm (79) control] in jaundiced animals, compared with sham-operated and control animals (p<0.02, Mann-Whitney U-test). Electron microscopy revealed oedematous change associated with mild inflammation, disruption of desmosomes, and the formation of lateral spaces between enterocytes. In addition, enterocytes showed vacuolation of their cytoplasm and mitochondrial swelling. Increased numbers of bacteria appeared to be attached to the mucosa. These data provide evidence of physical disruption of intestinal mucosa in jaundiced animals, most marked in the distal ileum. Significant bacterial translocation occurs following bile duct ligation and this supports the hypothesis of gut barrier dysfunction with obstructive jaundice.

The effects of sodium deoxycholate, lactulose and glutamine on bacterial translocation in common bile duct ligated rats.

BACKGROUND/AIMS: Sepsis is a major cause of post-operative morbidity and mortality in obstructive jaundice as a result of bacterial translocation from the gut. This study was conducted to investigate the effects of glutamine, lactulose, and the bile salt Na deoxycholate in preventing bacterial translocation in an animal model where obstructive jaundice was developed by common bile duct ligation. METHODOLOGY: Fifty Wistar albino rats were divided into 5 groups of 10 animals each. The animals in groups I-IV underwent common bile duct ligation and received, respectively, either saline, Na deoxycholate, lactulose or glutamine, orally. Group V had sham ligation and received saline orally. The animals were sacrificed at the end of the 7th day, and serum concentrations of bilirubin, aspartate aminotransferase (ALT), alanine aminotransferase (ALT), and alkaline phosphatase (AP) were measured. In addition, mesenteric lymph nodes were removed and cultured together with cecal content. Histopathologic examination of terminal ileum specimens was made. RESULTS: Na deoxycholate, lactulose and glutamine all reduced bacterial translocation rates to mesenteric lymph nodes (p<0.05), with glutamine causing the greatest effect. Na deoxycholate and lactulose prevented bacterial translocation by causing a decrease in cecal intraluminal bacterial content (p<0.001), while glutamine exerted its effect by preserving intestinal mucosal integrity. CONCLUSIONS: The integrity of the intestinal mucosal barrier is of paramount importance in preventing bacterial translocation, and the measures taken to protect mucosal integrity reduce bacterial translocation to a greater extent than those taken to decrease the number of bacteria in the gut.

[Intestinal bacterial translocation in patients with biliary tract diseases].

To determine whether intestinal bacterial translocation occurs in man, the authors cultured the tissues of mesenteric lymph nodes(MLNs), bile, portal and peripheral venous blood obtained prior to and during operation in 35 patients with biliary diseases. No positive peritoneal swab, portal blood and peripheral blood culture were shown. Thirteen of 20 patients with biliary obstruction (65%) had bacteria in their MLNs, while no positive MLN culture was found in 12 patients without biliary obstruction. The most common bacteria recovered from the MLNs were Gram-negative enteric bacilli. Thus, it is considered that extrahepatic biliary obstruction may induce intestinal bacterial translocation in man.

Clinical factors associated with positive bile cultures during primary percutaneous biliary drainage.

PURPOSE: To evaluate the utility of routine bile cultures and to determine the risk factors for bacterial colonization of the bile as well as the biliary flora in patients with biliary obstruction undergoing primary percutaneous biliary drainage. MATERIALS AND METHODS: Between October 1995 and January 1997, bile cultures were prospectively obtained in all patients undergoing percutaneous biliary drainage. Seventy-six patients underwent 86 procedures. Culture results were correlated with clinical, laboratory, and demographic variables. The antibiotic sensitivities of cultured organisms were examined. RESULTS: Fever, previous endoscopic or percutaneous biliary instrumentation, and bilioenteric anastomosis were significant predictors of a positive bile culture. In the absence of any of these indicators, bile cultures were unlikely to be positive. Enterococcus species was the organism isolated most commonly. Yeast, gram-negative aerobic bacilli, and Streptococcus viridans followed in frequency. CONCLUSION: Bile cultures provide valuable information that was useful for planning antibiotic prophylaxis and treatment. The likelihood of positive bile cultures can be predicted based on certain clinical variables. Continued investigation is needed to better predict bacterial flora in individual patients. Given the association between previous instrumentation and biliary colonization, noninvasive imaging modalities should be exhausted before invasive procedures are performed for solely diagnostic purposes in patients with biliary obstruction.

Role of the gut in the pathophysiology of extrahepatic biliary obstruction.

BACKGROUND: Gram negative septic events are the commonest source of morbidity and mortality as a result of surgery in jaundiced patients. The large intestine provides the major source of Gram negative bacteria in mammals and is implicated in the pathogenesis of systemic endotoxaemia in obstructive jaundice. Bile salts have an important part in maintaining indigenous microecological homeostasis through their emulsifying properties. AIMS: The aim was to investigate the effects of biliary obstruction and isolated external biliary diversion on gastro-intestinal structure and caecal bacterial flora in relation to bacterial translocation. METHOD: Six groups of adult male Wistar rats were studied (no operation, sham operated, and bile duct ligated (BDL) for one and three weeks and a choledocho-vesical fistula (CDVF) for one week). At the end of the study period plasma was assayed for evidence of endotoxaemia and the animals were tested for bacterial translocation to the mesenteric lymph node complex (MLNC), liver, lungs, and spleen. Quantitative and qualitative bacteriological studies were performed on the caecal contents and segments of colon and terminal ileum were washed and prepared for histological assessment. RESULTS: Bacterial translocation was significantly increased in the BDL1 (68.8%) and BDL3 (60%) groups compared with the sham1 (6.3%), sham3 (9.1%), No operation (0%), and CDVF1 (16.7%) groups. Although translocation was more pronounced in the BDL1 group, this was almost exclusively to the MLNC compared with the more widespread translocation to other organs in the BDL3 group. The BDL3 group was the only group with significantly raised concentrations of endotoxin and anticore glycolipid. The caecal Gram negative aerobic counts were significantly increased in the BDL1 and CDVF1 groups compared with all other groups. There was evidence of structural abnormalities in the terminal ileum of rats jaundiced for three weeks, but not in the other groups. CONCLUSIONS: Biliary obstruction for one and three weeks promotes bacterial translocation although the mechanisms may be different. Absence of intralumenal bile results in a significant but self limiting increase in the Gram negative aerobic population, which may account for translocation in the early stages of biliary obstruction. As the duration of biliary obstruction increases systemic endotoxaemia is a consistent feature which, combined with factors such as immunological depression and physical disruption of gut barrier function, may promote bacterial translocation perpetuating systemic sepsis.

Allopurinol and glutamine attenuate bacterial translocation in chronic portal hypertensive and common bile duct ligated growing rats.

BACKGROUND: Spontaneous bacterial infections and septicaemia result in morbidity and mortality in patients with portal hypertension and obstructive jaundice. AIM: The aim of this study in rats was to investigate the incidence of bacterial translocation in portal hypertension and obstructive jaundice, and to evaluate the effects of allopurinol and glutamine. METHODS: Rats were subjected to sham laparotomy (SL), portal hypertension (PH) by calibrated stenosis of the portal vein, and common bile duct ligation (CBDL). Animals of each group were either treated with allopurinol (50 mg/kg twice a week), glutamine (1 g/kg/d), and allopurinol and glutamine. RESULTS: After four weeks, significant bacterial translocation in the untreated PH and CBDL rats occurred. Intestinal mucosal malondialdehyde concentrations (MDA), as an indicator for lipid peroxidation, and myeloperoxidase activity (MPO) released from activated neutrophils were also significantly increased (p < 0.01). Allopurinol and glutamine in PH and CBDL rats improved bacterial translocation, and decreased MDA and MPO values (p < 0.01). CONCLUSION: In PH and CBDL rats significant bacterial translocation, ileal mucosal lipid peroxidation, and neutrophil derived MPO activity occurred. Allopurinol and glutamine significantly reduced bacterial translocation, as well as ileal mucosal MDA and MPO activities.

A bacteriologic and scanning electron microscope study after implantation of foreign bodies in the biliary tract in rats.

BACKGROUND: Bacterial adherence to the stent surfaces, concomitant colonization, and possible stent blockage are the main complications after the use of biliary stents. The present study was assigned to investigate bacteriologic and morphologic changes in the biliary tract after the implantation of biliary drain materials. METHODS: Rubber and silicone pieces with a surface area of 1 cm2 were implanted into the biliary tract in rats after temporary obstruction of the common bile duct by the use of a mini-occluder. The animals were killed at 4, 8 and 14 weeks, respectively, after implantation, and the implants were retrieved, cultured, and examined by scanning electron microscopy (SEM). Bacterial culture and SEM were also performed on tissue samples obtained from the mucosal surface of the biliary tract. RESULTS: Bacterial colonization and biofilm formation were found on the surfaces of the implanted materials and on the mucosal surface of the biliary tract in animals with implants but not on the biliary tract mucosa in rats without implants. CONCLUSION: Foreign bodies implanted in the biliary tract facilitate bacterial adherence not only to the surface of the implants but also to the mucosal surface in the biliary tract.

Colangite obstrutiva aguda / Acute obstructive cholangitis

Os autores discutem vários aspectos da colangite obstrutiva aguda com ênfase especial ao quadro clínico, diagnóstico diferencial e tratamento. Com relaçäo à etiologia referem que a coledocolitíase constituía-se na principal causa da colangite aguda. Entretanto, nos últimos anos, especialmente em centros de atendimento terciário, as manipulaçöes biliares näo cirúrgicas, geralmente em pacientes com neoplasias malignas irressecáveis, tornaram-se as causas mais frequentes de colangite. Enfatizam que o prognóstico é ruim, se a terapêutica instituida for retardada ou mal indicada. Finalmente, referem que cabe ao médico entender que pacientes com colangite obstrutiva aguda devem ser sempre tratados em caráter de urgência, tanto no que diz respeito ao diagnóstico como à terapêutica

[Alterations of oxygen free radicals in rabbit models and its relation to formation of pigment gallstones].

The experimental rabbits were divided into three groups. In the first group the common bile ducts were loosely ligated and contaminated by E. coli (BOI); in the second group the common bile ducts were only loosely ligated (BO); and the third group was the control group (Con). Alterations of oxygen free radicals were studied in all these models. The result showed that alterations of the partial hepatic oxygen free radicals (OFR), the hepatic prostaglandin E2 (PGE2) and the pigment gallstones were similar. There was a positive correlation among them (P < 0.05). In group BOI, these indexes were higher than in group BO. It is suggested that oxygen free radicals are possibly responsible for the formation of pigment gallstones through the pathway from oxygen free radicals to promote the production of prostaglandin E2, glycoprotein and pigment gallstones at last E. coli may aggravate the formation of pigment gallstones by increasing hepatic oxygen free radicals.