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Biomedical subjects

E G Hahn

Publications and source records attributed to E G Hahn.

At least 343 records · Page 19Linked to original sources
PubMed1996

Mucosal irritation, adaptive cytoprotection, and adaptation to topical ammonia in the rat stomach.

BACKGROUND: The urease-ammonia (NH4OH) system has been proposed to play a major role in the pathogenesis of the Helicobacter pylori-associated gastritis, but the mechanism of the mucosal damage has not been fully explained. This study was designed to examine possible adaptive cytoprotection and the adaptation of rat gastric mucosa to the irritant action of NH4OH and urease. METHODS AND RESULTS: Single application of NH4OH alone in various concentrations (15-500 mM) caused concentration-dependent mucosal damage starting with 30 mM and reaching a maximum at 250 mM NH4OH, similar to that obtained with 100% ethanol; it was accompanied by a decrease in gastric blood flow (GBF) to approximately 30% of the normal value. When the mucosa was first exposed to the low, non-damaging concentration (15 mM) of NH4OH and then insulted with 100% ethanol, the extent of ethanol damage was greatly attenuated as compared with that caused by ethanol alone. This adaptive cytoprotection was accompanied by the rise in GBF and reversed, in part, by the pretreatment with indomethacin, an inhibitor of prostaglandin (PG)-cyclooxygenase; with L-NAME, a blocker of NO-synthase; or with capsaicin deactivating the sensory nerves. Damaging concentrations of NH4OH (125 mM) caused widespread mucosal damage after the first application, but with repeated insults with 125 mM NH4OH a gradual reduction in the mucosal lesions, accompanied by enhanced mucosal cell proliferation and over-expression of epidermal growth factor (EGF) (using immunocytochemistry) and mRNA of EGF (using trans-reverse polymerase chain reaction), were observed. CONCLUSIONS: NH4OH alone damages gastric mucosa only at the concentration exceeding that found in H. pylori-infected stomachs, whereas at lower concentrations it acts as 'mild' irritant to induce adaptive cytoprotection. This adaptive cytoprotection appears to be mediated, in part, by endogenous PG, sensory nerves, and an arginine-NO-dependent pathway, and repeated applications of NH4OH induce gastric adaptation, probably mediated by enhanced expression of EGF and its receptors and by an increased cell proliferation.

Adaptation, Physiological↗
PubMed1996

[Abscess development caused by ingrown nitinol spiral as a fatal complication of a partially deteriorated MEMOSOND-PEG].

Percutaneous endoscopic gastrostomy (PEG) is a safe method with a low complication rate for providing enteral nutrition. While the "pull" method is the standard technique for PEG placement, alternatively "push" methods were developed in order to minimize peristomal wound infections caused by micro-organisms from the oropharyngeal cavity. Intragastral fixation of the "push" type PEG tube has always been a problem. The MEMOSOND-PEG uses a heat activated nitinol memory spiral as an anchor-like intragastral fixation. So far, an intraabdominal dislocation and a perforation have been reported as severe complications of this type of PEG tube. Five years after insertion we observed the development of an abscess induced by ingrowth of a nitinol spiral into the stomach wall as a further fatal complication in a patient with a MEMOSOND-PEG. The memory metal spiral had pierced the stomach wall after partial destruction of the polyurethane covering. The nitinol spiral was endoscopically extracted in several fragments. Ten days after extraction however, the patient died of combined kidney and liver failure due to a sepsis with Staphylococcus.

Abdominal Abscess↗
PubMed1996

Salivary and gastric luminal release of epidermal growth factor under basal conditions and after pentagastrin stimulation in healthy subjects and in duodenal ulcer patients before and after eradication of Helicobacter pylori.

Epidermal growth factor (EGF) is secreted by salivary and Brunner's glands and shows a potent inhibitory effect on gastric acid and stimulatory influence on mucosal growth and protection but little is known about the effect of the Helicobacter pylori (Hp) infection on the release of EGF. In this study the salivary and gastric concentrations of EGF have been measured and gastric mucosal expression of EGF has been determined in 25 Hp positive duodenal ulcer (DU) patients before and after the eradication of Hp (using triple therapy with omeprazole, 20 mg bd, amoxycillin, 500 mg qd and metronidazole, 500 mg bd for 2 weeks) and in 10 healthy controls under basal conditions and following pentagastrin (2 micrograms/kg-h) stimulation. Basal salivary and gastric concentrations of EGF were similar and no significant difference was found between DU patients and healthy controls. Pentagastrin infusion (2 micrograms/kg-h) caused a significant increase in EGF release into saliva and gastric juice both in healthy controls and DU patients but in DU patients the Hp eradication resulted in several folds higher basal and pentagastrin-induced gastric EGF content than that before the anti-Hp therapy, whereas such Hp eradication had no significant influence on basal and pentagastrin-induced salivary EGF. Antral mucosal expression of EGF in Hp-positive DU patients was significantly higher than that in healthy Hp-negative controls and this elevation persisted after eradication of Hp. Basal and pentagastrin-induced gastric acid outputs in Hp-positive DU patients were significantly higher than in healthy controls and they were slightly reduced after the triple therapy. In all DU patients, 4 weeks after termination of anti-Hp therapy, a complete ulcer healing occurred. We conclude that (1) the stomach is capable of secreting large amounts of EGF and pentagastrin appears to be a potent stimulus of salivary and gastric EGF release; (2) the Hp infection reduces the release of gastric EGF and the eradication of Hp results in the augmentation of basal and pentagastrin-induced EGF release into the stomach but not into the saliva and (3) since the eradication of Hp infection in DU patients resulted in DU healing and this was accompanied by an increase in EGF release, we conclude that EGF plays a crucial role in the DU healing process.

Duodenal Ulcer↗
PubMed1996

One week treatment with omeprazole, clarithromycin and tinidazole or lansoprazole, amoxicillin and metronidazole for cure of Helicobacter pylori infection in duodenal ulcer patients.

We defined optimal Helicobacter pylori (Hp) treatment as Hp eradication rate about 90%, well-tolerated with few side-effects. Two centers carried out randomized trials including 90 patients (74% men, 26% women, ages ranging from 18 to 65, mean age 42 +/- 8) with active duodenal ulcers (DU). Patients were treated with the combination of Omeprazole (O) 20 mg bd + Clarithromycin (C) 250 mg bd + Tinidazole (T) (500 mg bd) or with Lansoprazole (L) 15 mg bd + Amoxicillin (A) 750 mg bd + Metronidazole (M) 500 mg bd administered for one week. The DU healing rate was evaluated by endoscopy and the Hp status by rapid urease CLO-test and 14C-urea breath test (UBT). The healing rate of the DU in a group treated with the combination of O + C + T was 91% and in group treated with L + A + M was 93%. The eradication of Hp in group O + C + T and L + A + M averaged 91% and 87%, respectively. There was no statistically significant difference in the DU healing rate and the Hp eradication rate between these two groups. Both treatments were accompanied by a marked rise in the basal and postprandial plasma gastrin levels and the rise in the intragastric pH but these alterations returned to the pre-treatment values 4 weeks after the termination of the therapy. Both treatments were well tolerated and the only side effect was the taste disturbance observed in few patents treated with O + C + T. None of patients discontinued the treatment because of the adverse events. We conclude that one week treatment using O + C + T or L + A + M are highly and equally effective in the healing of DU and in the eradication of Hp.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1996

K-ras point mutations are rare events in premalignant forms of Barrett's oesophagus.

OBJECTIVE: In Barrett's adenocarcinomas, in contrast to squamous oesophageal carcinomas, K-ras point mutations are thought to be a frequent event. The frequency of K-ras point mutations in premalignant forms of Barrett's oesophagus (metaplasia, dysplasia) leading to adenocarcinoma with increased risk is currently not known. To establish the frequency of K-ras mutations in premalignant forms of Barrett's oesophagus, we investigated oesophageal biopsy specimens with Barrett's metaplastic and dysplastic epithelium for point mutations in the K-ras gene/codons 12, 13. DESIGN: A total of 412 biopsies from patients with Barrett's oesophagus were histologically classified into biopsies with metaplasia (n = 252), dysplasia (n = 105) and adenocarcinoma (n = 11), as well as biopsies distant from disease (normal, n = 37 and hyperplastic squamous epithelium, n = 7). METHODS: DNA from biopsy specimens was amplified by polymerase chain reaction (PCR) with a modified primer for generating a restriction site in the case of wild type in codon 12. Wild-type or point mutations in the K-ras gene/codons 12, 13 were detected by restriction fragment length analysis of the PCR products. RESULTS: Point mutations in K-ras/codon 12 were found in 9 biopsies (n = 1 in metaplasia, n = 4 in dysplasias, n = 4 in adenocarcinomas). All the other biopsies showed the wild type of K-ras/codon 12. No K-ras/codon 13 mutation (GGCgly-->GACasp) was observed. CONCLUSION: Mutations in K-ras/codon 12 were rarely found in premalignant forms of Barrett's oesophagus. Whereas the screening for K-ras point mutations in metaplastic sites of Barrett's epithelium seems not to be of practical value, the screening for mutations in dysplastic lesions might be helpful to estimate the individual risk for progression of Barrett's epithelium to adenocarcinoma. A further evaluation in larger numbers of patients is needed.

Adenocarcinoma↗
PubMed1996

Subserosal application of transforming growth factor-beta 1 in rats with chronic gastric ulcers: effect on gastric ulcer healing and blood flow.

Transforming growth factor beta 1 (TGF-beta 1) has been shown to play a central role in wound healing. This peptide has been detected in the stomach, but no information is available at present whether TGF-beta 1 influences the healing of gastric ulcers and whether the mucosal expression of TGF-beta 1 changes in the course of this healing. In this study, gastric ulcers were induced by serosal application of acetic acid and TGF-beta 1 or vehicle saline was injected twice into the subserosa around the ulcer area, once immediately after ulcer induction and two days later. Local application of TGF-beta 1 led to significant acceleration of gastric ulcer healing. Gastric blood flow at the ulcer margin was significantly higher than that in the ulcer crater but no significant difference was found in this flow between studied groups. Immunohistochemistry showed that the expression of TGF-beta 1 reached the peak at day 2 and then declined in the course of healing. We conclude that TGF-beta 1 accelerates ulcer healing possibly by increasing the formation of granulation tissue and cell migration probably mediated by locally expressed TGF-beta 1 but the healing effects of TGF-beta 1 do not depend on the vascular factor.

Animals↗
PubMed1995

[The risks of percutaneous endoscopic gastrostomy].

AIM OF STUDY: Percutaneous endoscopic gastrostomy (PEG) having established itself as the standard procedure and preferred method for artificial long-term intestinal nutrition, a retrospective study was undertaken to evaluate the complications and course after PEG. PATIENTS AND METHODS: 1299 patients in whom PEG had been performed between 1.8. 1984 and 1.8. 1993 were sent a standardised questionnaire, 1182 of which could be evaluated (954 males, 228 females; mean age 56.7 [3-94] years). RESULTS: Total duration of PEG was 279830 days, with a mean of 216.2 days per patient. Mortality rate due to the procedure was 0.5%. Severe complications (peritonitis, perforation or faulty puncture) occurred in 9 patients (0.9%). The most common relatively minor complications were peristomal wound infection (8.7%) and brief periods of abdominal pain (4.8%). Typical side effects specific to nutrition were gastrointestinal symptoms, like constipation, diarrhoea, meteorism, vomiting and other signs of illness (39.3%). CONCLUSION: Long-term intestinal nutrition via PEG is a safe, efficacious and cost-effective form of treatment which decreases demands on hospital care and reduces costs.

Adolescent↗
PubMed1995

[Self-expanding metal endoprosthesis in palliation of stenosing tumors of the upper gastrointestinal tract. Comparison of experience with three stent types in 82 implantations].

INTRODUCTION AND AIM OF STUDY: As there are no reports of studies comparing different self-expanding metal stent types the results obtained with three stent types in 73 patients (58 men, 15 women; mean age 65 [43-90] years who had a total of 82 implantation were analysed. PATIENTS AND METHODS: 31 Wallstents were implanted in 23 patients, 31 Ultraflex stents (all without covering) in 30 patients, and 20 Gianturco-Z stents (with covering) in 20 patients. The three groups of patients did not differ significantly with respect to degree of dysphagia, frequency of previous treatment, length of stenosis by tumour, tumour localization and histological tumour type. Six patients, treated with the Gianturco-Z stent, had an tracheo-oesophageal fistula. RESULTS: All 82 implantations were technically successful. Complete occlusion was achieved in all patients with fistulas, as proven radiologically. Serious early complications, namely stent migration, occurred in two patients (2.4%). The degree of dysphagia improved equally in all three groups (Wallstent, from 2.0 to 0.7; Ultraflex from 2.2 to 0.9, Gianturco-Z from 2.1 to 0.5 (not significant). The median follow-up time differed: 89 days for the Wallstent group, 129 for the Ultraflex group and 77 days for the Gianturco-Z group. Tumour ingrowth was the main problem with the non-covered stents. Accordingly, there were 43% reinterventions with the Wallstent, 37% with the Ultraflex and 20% with the Gianturco-Z stents. CONCLUSIONS: Self-expanding metal stents improve palliative treatment of stenosing tumours of the oesophagus and cardia, particularly in view of the low complication rate (< 3%) in the early postimplantation phase. But technical improvements are needed to reduce the number of reinterventions for restenosis in the follow-up period.

Adult↗
PubMed1995

[Fumaria officinalis (fumitory)--clinical applications].

Fumaria officinalis-fumitory or earth smoke-is a medicinal plant which has long had a role to play in empirical medicine in numerous countries. A review of the literature, however, reveals very few studies that support its use for dermatological indications (milk crust, eczema, scabies, etc.) or as a diuretic or laxative. This contrasts with its use to treat functional diseases of the biliary system. Although no placebo-controlled studies have been done, a number of empirical reports, clinical case reports and animal experimental studies have been published. Accordingly, in Germany, Fumaria officinalis is approved for the indication "colicky pain affecting the gallbladder and biliary system, together with the gastrointestinal tract".

Animals↗
PubMed1995

[20 years of endoscopic papillotomy. Analysis of 2752 patients at Erlangen Hospital].

Following the development and introduction of endoscopic papillotomy (EPT), 2752 procedures were performed at Erlangen University Hospitals between 1973 and 1993. All papillotomies were evaluated with regard to indications, technique, results, complications and mortality. To show the development process clearly, results for the periods 1973-1980 (A), 1981-1987 (B) and 1988-1993 (C) were summarised separately. The proportion of patients with common bile duct stones was 91% in group A, 60% in group B and 41% in group C. By contrast the number of papillotomies for malignant disease rose from 1% (A) to 26% (B) and 29% (C). More recent indications such as chronic pancreatitis (11%), biliary pancreatitis (5%) and others (for example sphincter of Oddi dysfunction) (11%) were first seen in group C. While the Erlangen standard papillotomy was used in almost all cases in group A (96%), the precut technique was used (mostly with needle knife) in one-third of all papillotomies in groups B and C (32%). The success rate for EPT in all three periods was highest for common bile duct stones (from 96% for group A to 98% for groups B and C). For malignancies, the success rate was lower (89% in groups B and C). The complication rate fell significantly with time (P < 0.05) from 11% (A) to 7.6% (B) and 6.3% (C). Precut techniques did not increase the complication rate. While 71% of all complications were treated surgically in period A, the proportions fell to 28% (B) and then to 7.5% (C). Method-related mortality fell from 1.1% (A) to 0.4% (B) and 0.5% (C).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1995

[Multicenter prospective study of the current status of treatment for bleeding ulcer in Germany].

The current state of ulcer treatment in Germany was analysed in a prospective multi-centre study. It was based on 1139 consecutive patients admitted to the participating hospitals because of upper gastrointestinal bleeding. The source of the bleeding was identified by diagnostic endoscopy in 1075 patients (94%), from a gastric and/or duodenal ulcer in 546 of them (mean age 62 +/- 18 years). Using Forrest's classification, 4% of patients were in bleeding stage Ia, 17% in stage Ib, 16% stage IIa, 30% stage IIb and 33% stage III. An attempt to arrest bleeding through the endoscope was made in 233 patients (43%): more often with tissue-preserving substances (epinephrine +/- NaCl in 36%, fibrin glue +/- epinephrine in 24%) than with tissue-damaging procedures (epinephrine + polidocanol +/- NaCl in 26%, epinephrine + thermocoagulation in 7%). Primary haemostasis was achieved in 219 patients (94%). There was a total of 66 recurrences of bleeding (12%), but the rate was 18% after endoscopic haemostasis. 64 patients (12%) required operative intervention, including initial emergency operations. Severe complications (infections, organic failure) occurred in 82 patients (16%). 114 of the 546 patients were in the high risk group (older than 60 years; high amount of bleeding). Their bleeding recurrence and mortality rates (27 and 22%, respectively) were significantly higher (P < 0.01) than those of the total group. Overall mortality rate was 11% (58 patients). The mortality rate depended on the severity of initial bleeding (26% for Forrest group Ia). After recurrent bleeding the mortality rate was 34% with conservative and 33% with operative treatment. 7% of all deaths were the direct result of bleeding. The following factors prognostically closely correlated with mortality rate: age of patient (P < 0.01); haemoglobin < 8 g/dl on admission (P < 0.05); initial severity of bleeding (Forrest group I; P < 0.05); and recurrence of bleeding (P < 0.001).

Age Factors↗
PubMed1995

Does acute ingestion of large amounts of alcohol cause pancreatic injury? A prospective study.

The contribution of ethanol to the pathogenesis of acute pancreatitis has been questioned for a long time. The authors asked whether acute ingestion of large amounts of alcohol may lead to pancreatic injury, as assessed by serum amylase levels, clinical picture, and abdominal ultrasound. Therefore, all patients (N = 122) admitted to our medical emergency ward with the diagnosis of alcohol intoxication were evaluated prospectively during a 12-mo period. Of these, 78 (56 M, 22 F; mean age 36 +/- 15) could be evaluated. The other 44 were excluded because of incomplete data (n = 18), mixed intoxications (n = 8), repeated admission (n = 9), incorrect diagnosis on admission (n = 7), and chronic pancreatitis (n = 2). Serum ethanol, amylase, and GOT were measured. Serum ethanol was 246 +/- 122 mg/dL (3-500 mg/dL), amylase 83 +/- 44 U/L (27-361 U/L), and GOT 25 +/- 37 U/L (5-271 U/L) without significant differences among the genders. No correlation between serum ethanol and serum amylase levels could be detected.

Acute Disease↗