IL-1beta-induced apoptosis in rat gastric enterochromaffin-like cells is mediated by iNOS, NF-kappaB, and Bax protein

BACKGROUND & AIMS

Enterochromaffin-like (ECL) cells are histamine-containing endocrine cells in the gastric mucosa. Previous studies have shown that the proinflammatory cytokine interleukin (IL)-1beta present during chronic gastritis inhibits histamine synthesis in ECL cells and leads to sustained functional impairment. This study investigated the effects of IL-1beta on ECL cell apoptosis and the related signal-transduction mechanisms.

METHODS

ECL cells were isolated by pronase digestion and a combination of elutriation, gradient centrifugation, and 48-hour culture (purity >/=90%). Apoptosis was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling reaction and cell death detection enzyme-linked immunosorbent assay.

RESULTS

IL-1beta (100 pg/mL) increased the rate of programmed cell death 2-3 fold in ECL cells after 24 hours of incubation (total of 12%-14%). This effect was completely inhibited by the NF-kappaB inhibitor, proteasome inhibitor I, and the nitric oxide synthase inhibitor (iNOS) N(G)-monomethyl-L-arginine (10(-4) mol/L), but not by the caspase 3 inhibitor, Asp-Glu-Val-Asp-CHO. Western blot analysis, reverse-transcription polymerase chain reaction (PCR), and in situ PCR showed that IL-1beta induced gene expression (after 2-4 hours) and protein synthesis (6-18 hours) of the iNOS isoform in ECL cells. Bax protein expression was increased in response to IL-1beta. In contrast, bcl-2 gene expression was increased in response to basic fibroblast growth factor, which has been shown to counteract IL-1beta- induced apoptosis.

CONCLUSIONS

These data suggest that IL-1beta induces programmed cell death in isolated rat ECL cells via activation of NF-kappaB, iNOS, and the Bax protein.

Reduced levels of coagulation factor XIII in patients with advanced tumor disease

BACKGROUND/AIMS

Coagulation factor XIII, which induces the stabilization of fibrin the final step in the coagulation cascade, has various physiological effects. Among these, its beneficial effect in gastrointestinal bleeding episodes is well known. With the exception of inflammatory bowel disease, however, few data are available about this effect, particularly with regard to its role in diffuse bleeding in tumor patients. The study was designed to carry out prospective follow-up investigations, gathering data concerning factor XIII levels in patients with advanced gastrointestinal tumors and evaluating the course of the disease as well as the incidence of bleeding.

METHODOLOGY

Sixty patients (22 women, 38 men; median age: 60; range: 29-79) with advanced gastrointestinal tumors were followed-up prospectively. Factor XIII levels were measured using chromogenic substrate. The correlation between the FXIII level and the patients' survival was analyzed using the Cox model.

RESULTS

Factor XIII deficiency (below 70%) was seen in only 7 patients (11.6%), 6 of whom died within a median of 1.5 months after the measurement. In all patients however, there was a significant correlation (P = 0.0133) between FXIII levels and the risk of death. Four bleeding episodes occurred in 3 patients, three times with FXIII levels being below the lower normal range. When substitution was attempted, it was only successful in 1 patient in whom the FXIII level was reduced.

CONCLUSIONS

FXIII may have predictive value as a marker for the prognosis in these patients with advanced tumor disease. Bleeding episodes were rarely seen, but when they do occur they may be associated with reduced levels of FXIII, and substitution may be beneficial as an adjunct or even as the sole therapeutic intervention.

Performance, patient acceptance, appropriateness of indications and potential influence on outcome of EUS: a prospective study in 397 consecutive patients

BACKGROUND

Although there is a large body of data on the accuracy of endoscopic ultrasonography (EUS) in the diagnosis and staging of various gastroenterological disorders, little has been published on the influence of EUS in the management of patients. Data on the performance of EUS and patient acceptance are also sparse.

METHODS

During a 10-month period, all consecutive EUS examinations were categorized by the examiner according to the appropriateness of the indications. Prior examinations, performance of EUS (duration, premedication, complications), and patient acceptance (assessed using a questionnaire by an independent investigator) were recorded. A mean of 2 months after the procedure, referring physicians were asked about the extent to which the EUS results had influenced their further diagnostic and therapeutic approach.

RESULTS

A total of 397 patients were included; they were referred for EUS after a mean of 1. 8 specific tests had been performed. The appropriateness of the indications for EUS was categorized as "classic," "useful," and "potentially useful" (categories 1 to 3) in 81% of cases. The referring physicians replied that EUS had provided useful additional information in 55% of cases; the EUS findings prompted further tests in 22% and made further examinations unnecessary in 30%. A change in therapy was believed to be directly due to EUS in only 6% of cases. The duration of the EUS examinations ranged from a mean of 8.1 minutes (esophageal indications) to 18.9 minutes (biliary indications). There were no complications. In patients who were able to remember the EUS examination (42%), 90% found it tolerable, and 83% of all the patients interviewed were willing to have the examination repeated with the same level of sedation.

CONCLUSIONS

EUS is a safe examination that can be carried out within a reasonable time frame by experienced examiners and without significant patient discomfort when performed under conscious sedation. With regard to patient management, EUS mainly influences further diagnostic tests.

Albumin dialysis: effective removal of copper in a patient with fulminant Wilson disease and successful bridging to liver transplantation: a new possibility for the elimination of protein-bound toxins

BACKGROUND

Acute liver failure may be the first manifestation of Wilson disease. If copper elimination fails, liver transplantation is the only remaining therapeutic option. Albumin dialysis, a new method for the removal of protein-bound toxins, was performed in a patient with fulminant Wilson disease.

METHODS

An 18-year-old man with Wilson disease presented with hyperacute liver failure, hepatic encephalopathy III, oligo-anuric renal failure, haemolytic anaemia, rhabdomyolysis, pancreatitis and thrombocytopenia. He was treated with albumin dialysis using a 44 g/l albumin-containing dialysate and a slow dialysate flow rate (1-2 l/h). The other details of the technique used are similar to routine continuous veno-venous haemodiafiltration.

RESULTS

One hundred and five milligrams of copper were removed by albumin dialysis within the first six treatments, resulting in normalisation of blood-copper levels. Successful treatment of the multiorgan failure was achieved. Hepatic encephalopathy improved within 2 days. The patient initially refused liver transplantation. Therefore 35 additional albumin dialysis treatments were performed. Forty-three grams of bilirubin (an indicator of detoxified substances in the liver) and 196 mg of copper were removed. Multiorgan failure, in particular hepatic encephalopathy, did not recur during 59 days of treatment. Eventually, the patient agreed to liver transplantation and that was successful.

CONCLUSION

Albumin dialysis is a new method for the effective treatment of fulminant Wilson disease, resulting in the removal of protein-bound toxins copper and bilirubin. It may serve as a new treatment option in hyperacute liver failure of other origin, acting as an extracorporeal detoxifier.

Long-term results of endoscopic and percutaneous transhepatic treatment of benign biliary strictures

BACKGROUND AND STUDY AIMS

Benign biliary strictures, mostly associated with biliary surgery, are of growing importance for the therapeutic endoscopist. In the short term, endoscopic therapy has success rates similar to those of surgery. With regard to the long-term results, fewer data are available, particularly concerning forms of treatment including percutaneous transhepatic biliary drainage (PTBD) as an additional tool. The present study was aimed at allowing evaluation of the short and long-term results of endoscopic and percutaneous treatment in patients with benign biliary strictures.

PATIENTS AND METHODS

The charts of 40 consecutive patients treated during the period 1992-1994 (12 men, 28 women; median age 60.5 years, range 24-86) were analyzed retrospectively. Long-term follow-up was carried out by direct contact. In almost all of the cases, the endoscopic treatment consisted of papillotomy and stenting (single stent treatment 10 or 11.5 Fr); Yamakawa-type prostheses (14 or 16 Fr) were used in the PTBD patients.

RESULTS

The primary treatment was successful in 37 of the 40 patients, including nine of 21 patients (43 %) treated endoscopically and 28 of 31 patients (90%) treated using the percutaneous approach. The complication rates after endoscopic retrograde cholangiopancreatography (ERCP) were 14%, compared with 26% after PTBD. Relief of the stricture was achieved in 25 patients after a median period of stent treatment of nine months (range 3-44), while recurrences were seen in six patients with stents in place for only 4.5 months (range 1-8), and in one patient with a metal stent. Therapy failed in two patients, and three were lost to follow-up. Serious long-term complications were rare, but there was a fatal complication in one patient with metal stents. The follow-up period was 44 months (range 11-66). Three patients underwent successful primary surgery, and three more underwent successful surgery after stricture recurrence; all were free of complaints after 49 months (range 40-44).

CONCLUSIONS

Endoscopic and percutaneous treatment of benign biliary strictures is not only a short-term treatment, but also an adequate long-term therapeutic alternative to surgery, with tolerable complication rates. The period of stenting appears to influence the outcome, and the diameter of the stents used also probably plays a role. Prospective studies are required for further evaluation of these observations.

Initial experience with a new Yamakawa-type prosthesis for long-term percutaneous transhepatic drainage

BACKGROUND AND STUDY AIMS

In a previous study evaluating the problems of long-term percutaneous transhepatic biliary drainage (PTBD) using Yamakawa-type prostheses in patients with benign and malignant stenoses, breakage of the tube proved to be a serious problem, occurring in 19.7 % of PTBD exchanges. As a consequence of these results, a new PTBD tube made of Tecothane has been developed.

PATIENTS AND METHODS

From September 1997 to September 1998, this new PTBD tube was applied in 64 patients (39 men, 25 women; median age: 70, range 29-89) in the treatment of benign (n = 30) or malignant stenoses (n=31; three stenoses remained indeterminate), and the course was followed.

RESULTS

A total of 134 stent exchanges were performed, 52 of these being ahead of schedule (39 %). Not a single case of breakage occurred. However, other PTBD-related problems remained unchanged. Patients accepted the new prosthesis very well; among 19 patients who had experience of both the new one and the conventional one, 11 had preferences-eight for the new one and three for the old one.

CONCLUSIONS

This new Tecothane prosthesis has solved the problem of PTBD breakage, which was often accompanied by serious problems. As was to be expected, other PTBD-related problems were not substantially affected. Nevertheless, this new tube represents progress in the percutaneous treatment of biliary stenoses.

Clinical relevance of the Helicobacter pylori gene for blood-group antigen-binding adhesin

Infection with Helicobacter pylori is associated with different human gastric diseases. Biochemical studies, in vitro adherence assays, and in vivo animal models revealed that epithelial attachment of H. pylori can be mediated by the blood-group antigen-binding adhesin (BabA) targeting human Lewis(b) surface epitopes. Studies with transgenic mice expressing the Lewis(b) epitope have shown that such attachment can alter disease outcome. In the current study, the presence of the babA2 gene encoding the adhesin was investigated in clinical isolates from a German population by using PCR and reverse transcription-PCR. A positive genotype was correlated to allelic variations in the genes encoding VacA and CagA and also to the prevalence of duodenal ulcer, distal gastric adenocarcinoma, mucosa-associated lymphoid tissue lymphoma, and antral gastritis. The presence of babA2 was significantly associated with duodenal ulcer (P = 0.0002) and adenocarcinoma (P = 0.033). In contrast, type 1 strains (vacAs1- and cagA-positive) were associated with only duodenal ulcer (P = 0.004) but not adenocarcinoma (P = 0.235). Genotype presence of babA2, vacAs1, and cagA ("triple-positive" strains) showed a highly significant correlation to the prevalence of ulcer (P = 0.000002) and adenocarcinoma (P = 0.014) and discriminated significantly better between disease outcome than did the current type 1 classification. These results indicate that the babA2 gene is of high clinical relevance and would be a useful marker to identify patients who are at higher risk for specific H. pylori-related diseases.

[Metal stents in gastroenterology]

Self-expanding metal stents have, when introduced in their constrained form through gastrointestinal and biliary strictures, a relatively small diameter. Once placed through the stricture and released, however, they expand to a much larger internal diameter, thus giving rise to sufficient palliative reopening of these strictures. Since metal stents are usually not removable, their primary use has been in malignant stenoses. Benign strictures should be treated with metal stents only in exceptional situations. For palliation of dysphagia in esophagocardial malignancies, metal stents have been shown to be associated with significantly fewer initial complications on placement than plastic tubes. The long-term fate of both stent types seems to be similar. In the palliation of malignant jaundice, metal stents were demonstrated to have a significantly longer patency rate, resulting in a favourable cost-benefit ratio despite the high price of metal stents. Continued developments are necessary to further reduce long-term complications and effectiveness.

[Prospective Epidemiologic Study of Epigastric Discomfort (PRESTO). Ground work and preliminary results]

BACKGROUND AND OBJECTIVE

Symptoms of dyspepsia (indigestion; upper abdominal discomfort) are one of the most frequent reasons for consulting a general practitioner or internist. Yet there are no up-to-date national data on the epidemiology and course of this symptom complex.

PATIENTS AND METHODS

In an open, prospective, multicentre, epidemiological study (PRESTO) 3016 patients with the suspected diagnosis of "functional dyspepsia" (1228 males, 1788 females, mean age 50 +/- 15 years) were followed for 2 years by 983 physicians in private practice (general practitioners or specialists in internal medicine). Patients with proven gastro-oesophageal reflux or peptic ulcer were excluded. Treatment was at the discretion of the physician. Patients were seen after one month (if under treatment) and then at 6, 12, 18 and 24 months. In addition to personal data, (1) symptoms, diagnosis and treatment of the dyspepsia, (2) socioeconomic aspects and (3) any limitations and the quality of life of each patient were recorded in a standard manner.

RESULTS

At the first interim analysis more than half the patients judged there situation to be one of "chronic stress" or having to cope with a stressful event; nearly 50% thought this to be the cause of the symptoms. Concomitant illnesses were present in 63% of patients. Oesophagogastroduodenoscopy with subsequent medication was performed in 20.6%, a trial of medication (usually drugs stimulating gastric motility) in 65%. No medication was initially given to 14.4% of patients. The most common symptoms were feeling of fullness (92.9%, epigastric pressure sensation (91.5%) and flatulence (87.4%).

CONCLUSION

These preliminary results indicate that a large epidemiological study can be performed by general practitioners and has advantages over the more usual method of enquiry by telephone. Dyspepsia exerts an unusually high degree of stress and results in considerable demands on medical facilities.

Growth factor effects on apoptosis of rat gastric enterochromaffin-like cells

Enterochromaffin-like (ECL) cells are histamine-containing endocrine cells in the gastric epithelium that show increased density during chronic atrophic gastritis. The current study determined cell number and apoptosis of isolated rat ECL cells in response to several growth factors. Isolated ECL cells from fundic mucosa (enrichment >90%) were grown in serum-free medium over 2-5 days. Cell number was determined by mitochondrial formazan production; apoptosis was measured by Tdt-mediated dUTP nick end labeling reaction and DNA fragmentation-based enzyme-linked immunosorbent assay. Immunocytochemistry and RT-PCR demonstrated the presence of epidermal growth factor receptor, neuronal growth factor receptor (type 1), and fibroblast growth factor (FGF) receptor (type 1). Gastrin (EC50, approximately 2 pM), transforming growth factor-alpha (TGF alpha; 10-30 ng/ml), and basic FGF (bFGF; 1-10 ng/ml) increased the total number of cultured ECL cells. bFGF augmented the gastrin (1 pM)-induced response. Beta-neuronal growth factor (10 ng/ml) and bFGF (2 ng/ml) decreased the programed death of ECL cells. Interleukin-1beta (100 pg/ml, 24 h) stimulated apoptosis 2- to 3-fold in ECL cells, and simultaneous incubation with TGF alpha (20 ng/ml) or bFGF (2 ng/ml) significantly inhibited this effect. ECL cells express specific receptors for gastrin, epidermal growth factor, neuronal growth factor, and FGF. bFGF prolonged ECL cell survival by inhibiting spontaneous apoptosis. Our data further indicate that TGF alpha and bFGF increase ECL cell number by inhibiting cytokine-induced programed cell death.

Microbiological examinations and in-vitro testing of different antibiotics in therapeutic endoscopy of the biliary system

BACKGROUND AND STUDY AIMS

Prior to endoscopic therapeutic procedures, no antibiotic prophylaxis is administered routinely. Because of the reported incidence of infectious complications, which may reach up to 10%, a prospective study was undertaken to investigate the effects of a prophylactic dose of cefuroxime on the incidence of bacteremia and clinical signs of infection, but no significant effects could be demonstrated. In addition to this published work, blood and bile cultures obtained in this trial were also investigated, and the in-vitro susceptibility to several antibiotics was tested in order to recommend the appropriate substances.

PATIENTS AND METHODS

Ninety-nine consecutive patients (51 men, 48 women; mean age 61.4 +/- 17 years) with biliary obstruction who underwent an endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography with drainage (PTCD) were included. Sequential blood cultures were taken before and up to 60 minutes after the endoscopic intervention. Bile cultures were obtained in 56 patients with biliary drainage. Aerobic and anaerobic cultures were prepared from all obtained specimens and the isolated organisms were identified. In the case of positive cultures, an in-vitro resistance test for 15 different antibiotics was performed.

RESULTS

The incidence of bacteremia was 11.1% (n = 11), and 16 bacteria were isolated. Twelve different microorganisms were detected, with Escherichia coli found in four cases. From 41 positive out of 56 prepared bile cultures (73.2%), 91 isolates were found with 25 different species. A single agent was detected in eight cases (19.5%), while a mixed growth, with pathogens ranging from two to six species, was found in 33 cases (80.5%). The seven most frequently isolated germs were E. coli and Enterococcus (each n = 19), Klebsiella (n = 10), Streptococcus viridans (n = 9), Staphylococcus epidermidis (n = 5), Morganella morganii (n = 4), and Bacteroides fragilis (n = 3), representing 76% of all agents. Examination for fungal infection revealed positive cultures of Candida albicans in 16.1% of bile cultures (nine of 56). Interestingly, the use of proton-pump inhibitors (PPIs), with a consequent rise in the gastric pH value, led to an increase in the rate of bacteremia to 26.2% (five of 19) compared to the other patients not on PPIs (n = 80), who developed bacteremia in only six cases (7.5%; p = 0.02). In-vitro testing of different antibiotics was carried out in 73 isolates. Imipenem showed the best antimicrobial activity (98.4%), followed by trimethoprim and sulfamethoxazole (90%), amoxicillin plus clavulanic acid (87.3%), vancomycin (82.4%), and ofloxacin (76.9%).

CONCLUSIONS

Escherichia coli was found to be the pathogen most frequently detected in blood and bile following endoscopic interventions in the biliary tract. Enterococci, Klebsiella and Streptococcus viridans were found in bile cultures with an incidence exceeding 10%. In view of the in-vitro test results, possible side effects, and contraindications, amoxicillin plus beta-lactamase inhibitors or quinolones are considered to be suitable antibiotics for the prophylaxis of biliary infections.

Significance of antibodies to the recombinant E2 protein of hepatitis G virus in haemodialysis patients

Patients on maintenance haemodialysis represent a high-risk group for parenterally transmitted viral infections, such as hepatitis B, C and G. In addition to hepatitis G virus (HGV) (GBV-C) RNA, analysed in previous studies, we characterized the seroprevalence rates of antibodies to the putative E2 protein (anti-E2) of HGV in a German cohort of patients on maintenance dialysis (n = 72) in comparison to healthy blood donors (n = 100). The presence of anti-E2 and/or HGV RNA as indicators of present or past HGV infection could be demonstrated in 34.7% of patients and in 16% of the blood donors (P < 0.01). The infection rates with HGV seem to increase only during the first 6 years of haemodialysis. The simultaneous presence of viraemia and anti-E2 was found very rarely in patients and controls. Therefore, the emergence of anti-E2 indicates clearance of HGV viraemia. In conclusion, patients on haemodialysis are at high risk of acquiring HGV infection, but a chronic carrier state with viraemia is rare. The risk of infection is not strictly correlated with the duration of dialysis.

Randomized study of intracorporeal laser lithotripsy versus extracorporeal shock-wave lithotripsy for difficult bile duct stones

BACKGROUND

Endoscopic treatment modalities are well established for the removal of bile duct stones. For the small percentage of stones that are difficult or impossible to extract by conventional means, more sophisticated endoscopic techniques or associated modalities such as intracorporeal laser lithotripsy (ILL) and extracorporeal shock wave lithotripsy (ESWL) have to be applied. Little is known, however, about the relative value of these different techniques. We therefore compared endoscopic ILL with ESWL in patients with difficult bile duct stones in a prospective randomized study.

METHODS

The study included 60 patients (35 women; mean age 70+/-15 years) with bile duct stones in whom standard extraction failed (n=33) or in whom the papilla was not accessible, thus requiring percutaneous access (n=27). They were randomized to receive ESWL under fluoroscopic targeting (maximum discharge number per session: 6000) or ILL using a pulsed dye laser with an automatic stone recognition system, which was mostly performed (28 of 30 cases) under cholangioscopic control. Endoscopic removal of fragments was attempted within the subsequent (ESWL) or the same (ILL) session. Failure was defined as failure to remove all ductal stones/fragments after a maximum of three lithotripsy sessions.

RESULTS

There were no statistical differences in background variables between the two groups. Bile duct clearance was achieved in 22 of 30 patients (73%) in the ESWL group and in 29 of 30 patients (97%) in the ILL group (p < 0.05). The number of treatment sessions (ESWL 3.0+/-1.3; ILL 1.2+/-0.4; p < 0.001) and the duration of treatment (ESWL 3.9+/-3.5 days; ILL 0.9+/-2.3 days; p < 0.001) were also significantly different in favor of ILL. Two minor complications occurred in each group; there was no 30-day mortality. Crossover therapy to ILL led to stone removal in seven of the eight cases in which ESWL failed, whereas ESWL fragmented the stone in the single patient in whom ILL failed.

CONCLUSIONS

ILL is more effective in the treatment of difficult bile duct stones than ESWL in terms of stone clearance rate and treatment duration.

Long-term results of endoscopic treatment of biliary duct obstruction due to pancreatic disease

BACKGROUND/AIMS

Endoscopic stenting has become an established method of providing palliative treatment in cases of malignant biliary obstruction, as well as in benign biliary stenosis. Several problems associated with the types of stent used have not yet been resolved, and an ideal stent has yet to be designed. Observation of the clinical course for patients with biliary obstruction of various etiologies, and evaluation of the results with various treatment methods are the aims of this study.

METHODOLOGY

In 1993 and 1994, biliary obstruction was treated endoscopically in 47 patients with a malignant pancreatic tumor and in 18 patients with chronic pancreatitis. The primary intervention was assessed retrospectively on the basis of the patients' records, and information concerning the clinical course was obtained by contacting the patients or their relatives or general practitioners.

RESULTS

Primary endoscopic drainage was successful in all cases. Only one of the patients with pancreatic tumors is still alive; survival after stent placement averaged 6.2 months. Metal stents remained patent significantly longer than plastic stents and percutaneous transhepatic biliary drains (PTBDs)(8.2 versus 3.5 or 1.9 months; p < 0.001). In cases of chronic pancreatitis, three of the nine patients who received only endoscopic treatment, without stenting, were able to continue without stents in the longer term, whereas seven of the nine who underwent surgery had no further problems.

CONCLUSIONS

Endoscopic drainage of biliary obstruction provides excellent short-term results. In long-term treatment for purely palliative purposes, metal stents remain patent for longer than plastic stents. In chronic pancreatitis, surgical treatment clearly seems to provide better long-term results than endoscopic therapy.

Long-term results of percutaneous transhepatic biliary drainage for benign and malignant bile duct strictures

BACKGROUND

Long-term percutaneous transhepatic biliary drainage (PTBD) is a valid alternative to surgery in patients with benign or malignant bile duct strictures in whom endoscopic drainage has failed. However, few data are available on the long-term outcome with percutaneous drainage, specially when the application of Yamakawa-type prostheses is considered.

METHODS

During 1996, 48 patients who were either treated with primary PTBD insertion followed by PTBD exchanges (n = 15) or who presented only for exchange of an earlier PTBD (n = 33) were included in the study. Thirty-one patients had malignant strictures, and 17 had benign ones. The PTBD catheters were scheduled for exchange every 3 months or earlier if signs and symptoms of obstruction or other problems were present. The data were collected prospectively during each follow-up visit and included both symptoms and the status and function of the PTBD at the time of exchange.

RESULTS

Although PTBD was highly effective in relieving jaundice (progression of cholestasis was observed in only 2 cases), 73 of the 157 PTBD exchanges (47%) had to be carried out earlier than scheduled. Premature exchange was needed for clinical reasons, such as fever indicating PTBD dysfunction, in only 19% of these cases. The other reasons were related to the PTBD catheter and consisted of bile leakage alongside the drain (33%), PTBD disconnection or complete dislocation (30%), or occlusion suspected during regular flushing of the drain (15%). In most cases exchanging the drain was sufficient to solve the problem; in cases of complete dislocation, dilation of the same tract (n = 6) or fresh puncture and establishment of a new drainage site (n = 2) were necessary. Reducing the PTBD exchange interval from 3 to 2 months would have decreased the number of premature stent exchanges by 26%.

CONCLUSIONS

Although PTBD is an effective method of biliary drainage, there are frequently minor problems-mostly catheter-related-which require premature exchange of the drain in almost half of the cases, and this may affect the patients' quality of life. Improvements in PTBD materials and catheter design are therefore needed. The effectiveness of reducing the intervals between PTBD exchanges should also be examined.

Biomagnetic 3-dimensional spatial and temporal characterization of electrical activity of human stomach

Biomagnetic measurements are based on the noninvasive recording of magnetic signals produced by biological sources such as nervous system and muscle. The aim of this study was to obtain multichannel magnetic field recordings from the human gastrointestinal tract and to localize the sources of these signals three-dimensionally. The magnetic field was recorded in eight human healthy subjects using a sensor array with 37 superconducting quantum interference devices (SQUIDs); an electrogastrogram was recorded simultaneously. Biomagnetic source localization was carried out with an iterative nonlinear optimization algorithm using the model of an equivalent current dipole (ECD) and correlated to magnetic resonance imaging (MRI) in four volunteers. Magnetogastrograms and electrogastrograms demonstrated a similar frequency distribution with a peak at 3/min. In all subjects the centers of the calculated dipoles plotted vs time showed a characteristic migration across the stomach area. One volunteer demonstrated tachygastric episodes, during which his magnetic field amplitudes increased fivefold and his dipole migration disappeared. In absence of an attack his recordings changed to normal. This demonstrates multichannel magnetic recordings can be used to localize the sources of the biomagnetic field, which could be useful for the understanding of motility disturbances.

[Polyposis of the gastrointestinal tract as a manifestation of diffuse follicular lymphatic hyperplasia]

HISTORY AND ADMISSION FINDINGS

A 21-year-old previously healthy Turkish man who had been living in Germany for 15 years was admitted because of worsening cramp-like abdominal pain with nausea, vomiting and watery diarrhoea. Palpation elicited diffuse muscular guarding over the entire abdomen and a mass of about 8 cm in the right lower abdomen.

INVESTIGATIONS

Abnormal laboratory results were erythrocyte sedimentation rate (55 mm), C-reactive protein (6.2 mg/dl), total bilirubin (2.1 mg/dl), creatine kinase (137 U/l) and thymidine kinase (5.5 U/l). There was a slight leucocytosis (13,700/microliter) and mild anaemia (haemoglobin 13.4 g/dl) with a normal differential count. Listeria ivanovii was repeatedly cultured from stool. Ultrasonography and computed tomography of the abdomen demonstrated a 6 cm mass in the right lower abdomen, splenomegaly (15.5 x 5 cm) and several lymphomas, up to 1.8 cm in diameter. Endoscopy revealed dense, in part grass-like, polyps, 3 to 6 mm deep, in the mucosa from the terminal ileum to the rectum, and to a lesser extent also in the duodenum. Histological examination of the polyps demonstrated diffuse follicular hyperplasia without evidence of malignancy.

TREATMENT AND COURSE

On antibiotic treatment with ofloxacin (2 x 400 mg intravenously) the symptoms quickly regressed, but the endoscopic findings remained unchanged.

CONCLUSION

Diffuse follicular lymphatic hyperplasia manifested itself in this patient as diffuse gastrointestinal polyposis. Listeria ivanovii cannot be ruled out as a causative factor.