Biomedical subjects
Publications and source records attributed to J Fritsch.
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BACKGROUND AND STUDY AIMS: Gastric outlet obstruction is a late event in the natural history of biliopancreatic tumours. Metallic self-expanding stents inserted under endoscopic and fluoroscopic guidance can be used for palliation. The aim of this study was to evaluate the feasibility, efficacy, and complications of endoscopic duodenal stenting in patients with malignant gastric outlet obstruction. PATIENTS AND METHODS: Between August 1998 and November 2001, 63 patients (31 women, 32 men; mean age 73 +/- 12) presenting with clinical symptoms of duodenal obstruction underwent endoscopic stenting with large metallic prostheses. Complications and clinical outcome were assessed both retrospectively and prospectively. RESULTS: Of the patients, 58 needed one duodenal stent and two overlapping stents were required in five patients. Stenting was immediately successful in 60/63 patients (95%). At the time of the duodenal procedure, 25 previously inserted biliary stents were still patent; biliary stenting was attempted during the same procedure in 18 patients; and 20 patients had no biliary stricture. There was no procedure-related mortality. There were complications in 30 % of patients: 13 stent obstructions, 4 stent migrations and 2 duodenal perforations (treated surgically). For 44 patients (70%) there were no minor or major digestive problem during their remaining lifetime. An exclusively peroral diet was possible in 58 patients (92%), but was considered satisfactory (solid or soft) in 46/63 patients (73%). Of the patients, 53 (84 %) died between 1 and 64 weeks after the duodenal stenting (median survival 7 weeks). CONCLUSIONS: Endoscopic stenting for the palliation of malignant gastric outlet obstruction is feasible and well-tolerated in most patients. Most dysfunctions can be managed endoscopically.
An exceptional cause of obstructive jaundice is reported in the present case. A 51-year-old woman progressively developed jaundice with pruritus, and abdominal ultrasonography revealed dilated intra- and extrahepatic bile ducts. Endoscopic retrograde cholangiography and endoscopic ultrasonography showed a tumor in the distal common bile duct, but failed to determine the nature of the lesion, and the patient underwent a pancreaticoduodenectomy. The final diagnosis was an inflammatory pseudotumor of the common bile duct. Inflammatory pseudotumors are uncommon, without evident pathogenesis, and are described in many organs. The localization in the common bile duct is exceptional. The prognosis is good, and a more conservative approach is possible if the diagnosis is certain before surgery.
Helium atom diffraction experiments carried out under ultrahigh vacuum conditions on a freshly cleaved (001) surface of KTaO3 reveal metastable features which decay over a period of several hours. The initial He diffraction pattern contains large scattering intensity satellite peaks very close to the specular reflection beam. As time from cleaving elapses, the satellite intensities diminish virtually to zero while the specular intensity increases, and the diffraction pattern evolves into one consistent with the (1x1) bulk termination surface. The data are compared with model calculations for scattering from a series of terraces at two heights with a distribution of terrace lengths [Surf. Sci. 384, 15 (1997)].
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The almost ubiquitously expressed ClC-2 chloride channel is activated by hyperpolarization and osmotic cell swelling. Osmotic swelling also activates a different class of outwardly rectifying chloride channels, and several reports point to a link between protein tyrosine phosphorylation and activation of these channels. This study examines the possibility that transforming growth factor-alpha (TGF-alpha) modulates ClC-2 activity in human colonic epithelial (T84) cells. TGF-alpha (0.17 nM) irreversibly inhibited ClC-2 current in nystatin-perforated whole cell patch-clamp experiments, whereas a superimposed reversible activation of the current was observed at 8.3 nM TGF-alpha. Both effects required activation of the intrinsic epidermal growth factor receptor (EGFR) tyrosine kinase activity, of phosphoinositide 3-kinase, and of protein kinase C. With microspectrofluorimetry of the pH-sensitive fluorescent dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, TGF-alpha was shown to reversibly alkalinize T84 cells at 8.3 nM but not at 0.17 nM, suggesting that 8.3 nM TGF-alpha-induced alkalinization activates ClC-2 current. This study indicates that ClC-2 channels are targets for EGFR signaling in epithelial cells.
Radiation-induced lesions of the bile ducts rarely occur and may be difficult to manage. We report the case of a 59-year old woman who developed radiation-induced stenosis of the papilla and the common bile duct 25 years after abdominal radiation therapy for abdominal non-Hodgkin's lymphoma. She presented with recurrent cholangitis and chronic cholestasis. Endoscopic results showed dilation of the intrahepatic bile ducts, radiation-induced inflammation and narrowing of the antrum and the duodenum, and stricture of the papilla and the last few millimeters of the common bile duct. The patient was treated with endoscopic balloon dilation. Forty-two months after endoscopic dilation, the patient remained asymptomatic with normal liver tests and no biliary dilation at ultrasound.
The number of complex cystic fibrosis transmembrane conductance regulator (CFTR) genotypes identified as having double-mutant alleles with two mutations inherited in cis has been growing. We investigated the structure-function relationships of a severe cystic fibrosis (CF)-associated double mutant (R347H-D979A) to evaluate the contribution of each mild mutation to the phenotype. CFTR mutants expressed in HeLa cells were analyzed for protein biosynthesis and Cl(-) channel activity. Our data show that R347H is associated with mild defective Cl(-) channel activity and that the D979A defect leads to misprocessing. The mutant R347H-D979A combines both defects for a dramatic decrease in Cl(-) current. To decipher the molecular mechanism of this phenotype, single and double mutants with different charge combinations at residues 347 and 979 were constructed as charged residues were involved in this complex genotype. These studies revealed that residue 979, located in the third cytoplasmic loop, is critical for CFTR processing and Cl(-) channel activity highlighting the role of charged residues. These results have also important implications for CF, as they show that two mutations in cis can act in concert to alter dramatically CFTR function contributing to the wide phenotypic variability of CF disease.
In the field of industrial hygiene, besides the necessity of monitoring phosphine with direct reading apparatus to prevent accidents, there is a need for a method of sampling and analysing phosphine to control workers' exposure. The use of filters impregnated with silver nitrate to collect arsine, phosphine and stibine in workplace air has been described in the literature. Having previously chosen this type of filter to collect arsine, we studied its characteristics for phosphine capture. A filter impregnated with sodium carbonate was used both as a prefilter to collect the particles and to trap arsenic trioxide. After dissolving the silver compounds in nitric acid, ICP emission spectrometry was used to carry out the analysis. This article describes the comparative sampling we performed in a microelectronic laboratory and in a fumigation chamber (130 samples) to determine the concentration of AgNO3 impregnation solution to be used, the detection limit of the method and the retention capacity of the impregnated filters. Interference with other gases reacting with silver nitrate was studied and the storage time for sampled filters and analysis solutions was checked. The detection limit of the adopted method is better than 1 microg per filter, and the retention capacity exceeds 300 microg per filter. The problem of how to sample phosphine when H2S, NH3, or HCl is present has been solved, but the problem of sampling phosphine in atmospheres where acetylene evolves remains. Sampled filters and filter solutions are stable for more than three months at ambient temperature.
UNLABELLED: The aim of this retrospective study was to evaluate the nature and the frequency of biliary complications after endoscopic retrograde cholangiography for common bile duct stones in elderly patients with gallbladder in situ. METHODS: Between 1991 and 1993, 169 consecutive patients with gallbladder in situ, older than 65 years (79 +/- 8) had an endoscopic retrograde cholangiography with sphincterotomy for choledocholithiasis. Information on the early (<1 month) and late biliary complications, treatment and mortality were obtained by mail or phone calls from patients and general practitioners. Long-term data were obtained for 139 patients (82%). Mean follow-up was 56.5 months (80 months for patients still alive at the end of the study). RESULTS: Early complications occurred in 13 patients (10.8%). Seven patients had acute cholecystitis, present before the procedure in all cases; all were treated by surgery. Other early complications included cholangitis (n =7), mild acute pancreatitis (n =3), bleeding (n =1), perforation (n =1), biliary colic (n =1), pneumopathy (n =1) and bradycardia (n =1), all treated medically. Forty patients underwent early cholecystectomy, and 5 died during the first month without biliary disease. Late complications were thus assessed in 94 patients and occurred in 13 (14%), i.e around 2% per year. Complications were acute cholangitis (n=4), biliary pain (n =4), cholecystitis (n =2), abdominal pain (n =2) and jaundice due to sphincterotomy stenosis (n =1). Five patients had cholecystectomy, 1 a radiological drainage and 7 were treated medically. No death due to a biliary complication was observed. The presence of gallstones, the absence of gallbladder opacification at cholangiography were not prognostic factors for the recurrence of biliary symptoms. 65 patients (50%) died without biliary disease during the follow-up (actuarial death rate 10.5% per year). CONCLUSION: Late biliary complications after endoscopic retrograde cholangiography for choledocholithiasis in patients with gallbladder in situ are rare (2% per year). Prophylactic cholecystectomy after sphincterotomy does not seem warranted in elderly patients, because of rare recurrent biliary symptoms, low mortality rate, and limited life expectancy.
BACKGROUND: Magnetic resonance cholangiography (MRC) is a new technique for non-invasive imaging of the biliary tract. AIM: To assess the results of MRC in patients with suspected bile duct stones as compared with those obtained with reference imaging methods. PATIENTS/METHODS: 70 patients (34 men and 36 women, mean (SD) age 71 (15.5) years; median 75) with suspected bile duct stones were included (cholangitis, 33; pancreatitis, three; suspected post-cholecystectomy choledocholithiasis, nine; cholestasis, six; stones suspected on ultrasound or computed tomography scan, 19). MR cholangiograms with two dimensional turbo spin echo sequences were acquired. Endoscopic retrograde cholangiography with or without sphincterotomy (n = 63), endosonography (n = 5), or intraoperative cholangiography (n = 2) were the reference imaging techniques used for the study and were performed within 12 hours of MRC. Radiologists were blinded to the results of endoscopic retrograde cholangiography and previous investigations. RESULTS: 49 patients (70%) had bile duct stones on reference imaging (common bile duct, 44, six of which impacted in the papilla; intrahepatic, four; cystic duct stump, one). Stone size ranged from 1 to 20 mm (mean 6.1, median 5.5). Twenty seven patients (55%) had bile duct stones smaller than 6 mm. MRC diagnostic accuracy for bile duct lithiasis was: sensitivity, 57.1%; specificity, 100%; positive predictive value, 100%; negative predictive value, 50%. CONCLUSIONS: Stones smaller than 6 mm are still often missed by MRC when standard equipment is used. The general introduction of new technical improvements is needed before this method can be considered reliable for the diagnosis of bile duct stones.
AIMS: The hydrostatic dilatation of the papilla of Vater, or sphincteroclasy, has been recently proposed as an alternative to endoscopic sphincterotomy. Our aim was to assess short term results and follow-up after sphincteroclasy for choledocholithiasis. METHODS: From August, 1994 to December, 1996, 52 patients were included for endoscopic therapy of choledocholithiasis (mean age 66 +/- 17 years). Patients were prospectively followed on the short term-period (24 h, 48 h and 30 days) and longer term after treatment (every 6 months) by clinical and biological controls. MAIN RESULTS: Forty-eight sphincteroclasies were performed successfully (92.3%). Thirty seven patients had a choledocolithiasis. Eleven were stone-free. Eight had undergone former gastric surgery and 8 had impaired coagulation test. Complete stone clearance was achieved in 98% of patients. Mild pancreatitis were observed in three patients (6.25%). Thirty-day mortality was nil. Long term follow-up (mean 21.4 +/- 7 months) revealed: 2 patients with cholecystitis 6 and 13 months after treatment, one of which was followed 8 months later by a fatal septic shock, and 3 patients with cholangitis, 2 of which in the same patient, 9, 12 and 24 months after sphincteroclasy. The global long term biliary complication rate was 8.4%, 4.2% of which were potentially related to the endoscopic procedure. CONCLUSION: Sphincteroclasy is an efficient procedure for the treatment of choledocholithiasis. Its short term results are similar to those of endoscopic sphincterotomy. Complications after 2 years appear to be scarce, but longer follow-up is required before routinely performing sphincteroclasy.
We describe three cases of spontaneous intramural hematoma of the esophagus, a rare pathology. The combination of chest pain, dysphagia and hematemesis and often the existence of hemostasis disorders or fragility of the mucosa, or trauma of the esophagus, should evoke the diagnosis. Radiology (thoracic scan, barium swallowing) and esophagoscopy enable confirmation of the diagnosis, permitting conservative treatment and simple spontaneous course of this pathology.
BACKGROUND: Although metallic stents remain patent longer than plastic stents, the optimal palliation of inoperable malignant biliary strictures remains controversial because of the high cost of metallic stents and short patient survival. METHODS: A total of 101 patients (mean age 72.5+/-12.9 years) with malignant strictures of the common bile duct were included in this study, after three exclusions for technical failure (n = 3) and one for noncompliance with study design. The etiology of the strictures included pancreatic cancer (65), cholangiocarcinoma (21), ampullary tumor (3), and metastatic lymph nodes (12). Patients were randomized to receive either an 11.5F polyethylene stent to be exchanged in case of dysfunction (group 1, n = 33), an 11.5F stent to be exchanged every 3 months (group 2, n = 34), or a self-expanding metallic Wallstent (group 3, n = 34). RESULTS: Endoscopic procedures were successful (including complete relief of jaundice) in 97.1 % of cases. Procedure-related morbidity was 11.9%, and mortality was 2.9%. Bilirubinemia after 48 hours (37.2%+/-21.7% decrease from the preoperative level) did not differ between groups. Patients were followed for a mean of 166 days (median 143, range 0 to 596 days). Overall survivals were not different between groups, but complication-free survival for groups 2 and 3 was longer than that of group 1 (p < 0.05). Cumulated hospital days were 7.4+/-1.5, 10.6+/-1.7, and 5.5+/-1.4 (groups 1, 2, and 3, respectively) (p < 0.05; analysis of variance). Cost analysis showed that metallic stents were advantageous in patients surviving more than 6 months, whereas a plastic stent was advantageous in patients surviving 6 months or less. CONCLUSIONS: Metallic stents and plastic stents exchanged every 3 months are valuable alternatives for increasing complication-free survival in patients with malignant strictures of the common bile duct. Metal stents are advantageous in patients with the longest life expectancy.
BACKGROUND: Stenting is the treatment of choice for inoperable malignant strictures of the common bile duct. Criteria for the choice of stents (plastic versus metallic) remain controversial because predicting survival is difficult. AIMS: To define prognostic factors in order to improve the cost effectiveness of endoscopic palliation. PATIENTS: One hundred and one patients were included in a prospective trial. Seven prognostic variables for survival were analysed (age, sex, bilirubinaemia, weight loss, presence of liver metastases, and tumour histology and size). All patients were followed until death or at least one year after inclusion. By the end of the study, 81 (80.2%) patients had died. RESULTS: In univariate analysis, the variables associated with survival were weight loss (p < 0.05) and tumour size (p < 0.01). By multivariate analysis, tumour size was the only independent prognostic factor (p < 0.05). A threshold of 30 mm at diagnosis distinguished two survival profiles: the median survival of patients with a tumour greater than 30 mm was 3.2 months, whereas it was 6.6 months for patients with a tumour less than 30 mm (p < 0.001). CONCLUSIONS: A practical strategy could be based on tumour size at diagnosis: a metal stent should be systematically chosen for patients with an inoperable tumour smaller than 30 mm, while larger tumours are efficiently palliated by a plastic stent.
Inflammatory fibroid polyp is an uncommon lesion involving the stomach, the small bowel and occasionally the colon. Inflammatory fibroid polyp is a large polypoid lesion arising from the submucosa. It has no malignant potential although extensive infiltration may occur. The main histological characteristics are diffuse inflammatory infiltrate with eosinophils and highly vascularized fibrocytic stroma. Immunohistochemistry is always positive for vimentine and negative for S 100 and desmin. We report four cases of inflammatory fibroid polyps, 3 of which mimicked carcinoma of the colon. Exploratory laparotomy and histopathological examination of the resected specimen were necessary to confirm definitive diagnosis. In the last case, diagnosis was established by histological examination of an endoscopically-removed colonic polyp.
OBJECTIVES: Laparoscopic cholecystectomy is the standard treatment of symptomatic gallstones. At present, no consensus has been reached on the diagnostic and therapeutic methods of concomitant common bile duct stones. Systematic preoperative endoscopic ultrasonography followed, if necessary, by endoscopic retrograde cholangiography and sphincterotomy during the same anesthetic procedure could be a diagnostic and therapeutic alternative for common bile duct stones making possible a laparoscopic cholecystectomy without intraoperative investigation of the common bile duct. METHODS: One hundred and twenty-five patients underwent a prospective endoscopic ultrasonographic evaluation prior to laparoscopic cholecystectomy for symptomatic gallstones. Fourty-four patients (35%) had at least one predictive factor for common bile duct stones. Endoscopic ultrasonography and cholecystectomy were performed on the same day. Endoscopic ultrasonography was followed by endoscopic retrograde cholangiography and sphincterotomy by the same endoscopist in case of common bile duct stones on endoscopic ultrasonography. Patients were routinely followed up between 3 and 6 months and one year after cholecystectomy. RESULTS: Endoscopic ultrasonography suggested common bile duct stones in 21 patients (17%). Endoscopic ultrasonography identified a stone in 17 of 44 patients (38.6%) with predictor of common bile duct stones and only in 4 of 81 patients (4.9%) without predictor of common bile duct stone. Among these 21 patients, one patient was not investigated with endoscopic retrograde cholangiography because of the high risk of sphincterotomy, 19 patients had a stone removed after sphincterotomy, one patient had no visible stone neither on endoscopic retrograde cholangiography, nor on exploration of the common bile duct after sphincterotomy. Endoscopic ultrasonography was normal in 104 patients (83%). However, two patients in this group were investigated with endoscopic retrograde cholangiography because endoscopic ultrasonography was incomplete in one case and because endoscopic ultrasonography was normal in the second case but a stone in the left hepatic duct was detected by ultrasonography. A stone was removed after endoscopic sphincterotomy in these two patients. In the group of 102 patients without stone, 91 out of 92, continued to be asymptomatic during a median follow-up of 8.5 months. One patient with symptoms one month after cholecystectomy underwent endoscopic sphincterotomy but no stone was found. CONCLUSIONS: Systematic preoperative endoscopic ultrasonography followed, if necessary with endoscopic retrograde cholangiography and sphincterotomy is a diagnostic and therapeutic alternative for common bile duct stones making possible a laparoscopic cholecystectomy without intraoperative investigation of the common bile duct for all patients. This alternative is only justifiable in patients with predictor of common bile duct stones.