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N Lehn

Publications and source records attributed to N Lehn.

At least 73 records · Page 4Linked to original sources
PubMed1997

Histological diagnosis of Helicobacter pylori gastritis is predictive of a high risk of gastric carcinoma.

Chronic Helicobacter pylori infection has been identified as a major risk factor for the subsequent development of gastric carcinoma On the basis of seroepidemiological studies the relative risk for infected persons was estimated to range between 3 and 6. Our study attempted to determine the relative risk of gastric carcinoma in H. pylori-infected individuals based on the histological evaluation of gastritis in gastric carcinoma patients in the light of a declining prevalence of H. pylori infection in Western countries. We histologically determined the H. pylori infection rate in 215 patients with early gastric carcinoma (tumor stage pT1), and compared it with that of 215 asymptomatic persons matched by age and sex who were tested by the 13C urea breath test. On the basis of these data an odds ratio of 16.7 (CI 9.6-29.1) was calculated for the relative risk of developing gastric carcinoma in H. pylori-infected people. The histological diagnosis of gastritis permits a separate risk assessment for patients with autoimmune gastritis, and by excluding these patients from the analysis we calculated an odds ratio for H. pylori-infected persons of 150 (CI 36.4-622.9). The endoscopic-histological diagnosis of H. pylori infection is associated with an increased risk of the subsequent development of gastric carcinoma of approximately 150-fold compared with H. pylori-negative patients who do not have chronic atrophic corpus gastritis of the autoimmune type (type A gastritis).

Adult↗
PubMed1997

Differing degree and distribution of gastritis in Helicobacter pylori-associated diseases.

Infection with Helicobacter pylori (H. pylori) causes gastritis, and may be associated with gastric and duodenal ulcers and also with such malignant diseases as MALT lymphoma and gastric carcinoma. In order to determine whether there are differences in the degree and distribution of gastritis, each patient with H. pylori gastritis only (n = 50) was matched for sex and age with four patients, one each with H. pylori-associated duodenal ulcer, gastric ulcer, gastric carcinoma or MALT lymphoma. From each patient, two biopsies were taken from the antrum and two from the corpus for histopathological examination of H. pylori gastritis. The median summed gastritis score decreases in the following order: antrum: gastric ulcer > duodenal ulcer > gastritis alone > carcinoma > MALT lymphoma, and corpus: gastric ulcer > carcinoma > MALT lymphoma > gastritis alone and duodenal ulcer. We conclude that the degree and distribution of H. pylori gastritis differs significantly among H. pylori-associated diseases. These differences may explain some of the underlying pathomechanisms associated with H. pylori infection.

Adult↗
PubMed1997

An increasing dose of omeprazole combined with amoxycillin cures Helicobacter pylori infection more effectively.

BACKGROUND: The combination of omeprazole and amoxycillin has demonstrated effectiveness with very few side-effects in the treatment of H. pylori infection, however cure rates have varied widely. The present study addresses the question as to the extent to which the cure rate of H. pylori infection depends on the size of the daily omeprazole dose, and investigates other patient-related factors that influence treatment success. METHODS: In a randomized, controlled and investigator-blinded trial, 163 hospitalized patients with H. pylori-associated gastritis were treated with 20 mg omeprazole once daily in the morning, 20 mg omeprazole b.d., 40 mg omeprazole b.d. or 60 mg omeprazole b.d. for 14 days. In addition, all patients received 1000 mg amoxycillin b.d. on days 5-14. Endoscopic and histological examinations were performed prior to treatment, at the end of treatment and 4 weeks after completion of treatment. RESULTS: H. pylori infection was cured in 18 of 40 (45%, 95% CI: 29-62%), in 22 of 39 (56.4%, 95% CI: 40-72%), in 25 of 38 (65.8%, 95% CI: 49-80%), and in 33 of 40 (82.5%, 95% CI: 67-93%) patients, respectively, (P < 0.001). Side-effects leading to discontinuation of treatment occurred in only 1.2%. CONCLUSION: The daily dose of omeprazole is an important factor for the success of dual therapy comprising omeprazole and amoxycillin in curing H. pylori infection. Cure of H. pylori infection correlates positively and significantly with the size of the daily omeprazole dose. The combination of high-dose omeprazole and amoxycillin is an effective and well-tolerated regimen for the treatment of H. pylori-associated diseases.

Adolescent↗
PubMed1997

Is the polymerase chain reaction or cure of Helicobacter pylori infection of help in the differential diagnosis of early gastric mucosa-associated lymphatic tissue lymphoma?

PURPOSE: The differential diagnosis of early gastric mucosa-associated lymphatic tissue (MALT) lymphoma based on Helicobacter pylori gastritis may be difficult when lymphoepithelial lesions are not detected. The aim of the present study was to investigate the question whether the polymerase chain reaction (PCR) or cure of H pylori infection may be of help in this respect. PATIENTS AND METHODS: Twenty patients with suspected low-grade gastric MALT lymphomas were treated in a double-blinded, randomized, crossover trial with 2,250 mg of either amoxicillin or placebo, both in combination with omeprazole, for 14 days with the aim to cure H pylori infection. PCR was performed using primers specific for the CDR3 region to detect monoclonal B cells. RESULTS: In five of 20 patients, MALT lymphomas were finally diagnosed. Three of these five patients went into complete remission, while two were referred to surgery. In the 15 patients with gastritis, complete regression was observed in all cases. With respect to PCR, monoclonal bands were detected in all four of the analyzed lymphoma patients before histology showed lymphoma. In addition, monoclonal bands were found in three patients with gastritis. In the patients with gastritis and monoclonal PCR, complete regression took longer as compared with the remaining 12 patients with polyclonal PCR and gastritis (P = .0209). Successful H pylori eradication was associated with earlier diagnosis of the MALT lymphoma (P = .0237). CONCLUSION: CDR3-PCR may be of help in the differential diagnosis of early gastric MALT lymphoma. Furthermore, H pylori eradication may lead to earlier diagnosis.

Adult↗
PubMed1996

Granulocyte activation by Helicobacter pylori.

Helicobacter pylori-associated gastritis (HAG) is characterized by granulocytic and mononuclear cell infiltrates within infected gastric mucosa. Since the bacterium does not invade the epithelial layer, it must be assumed that components or products of the pathogen which permeate the epithelial barrier may initiate chemotaxis and activation of neutrophils. The aim of this study was to evaluate the effect of H. pylori water soluble protein (WSP) components on the induction of granulocyte adherence and activation. The results show that H. pylori WSP led to enhanced expression of the beta 2-integrin CD11b/CD18 on the granulocyte surface. Following upregulation of this adhesion molecule, activated granulocytes demonstrated increased adhesion to human endothelial cells (HUVEC) in culture. These observations support the hypothesis that in vivo neutrophil activation may be a direct result of H. pylori constituents promoting transendothelial migration into the lamina propria of infected gastric mucosa.

Bacterial Proteins↗
PubMed1996

[Antibiotic prophylaxis using cefuroxime in bile duct endoscopy].

OBJECTIVE: To assess prospectively the effectiveness of a single prophylactic dose of cefuroxim before therapeutic endoscopy, in view of the general practice not to give antibiotics routinely. PATIENTS AND METHODS: In a prospective study endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography with drainage (PTCD) together with simultaneous stone extraction, dilatation or stent implantation were performed in 99 patients (51 men, 48 women; mean age 60.6 +/- 19.2 years). Group A (n = 49) received 1500 mg cefuroxim i.e. 30 min before the procedure, while none was given to group A patients (n = 50). Several blood cultures were taken up to 60 min after the endoscopy. The number of septicaemias (bacteraemia with fever, rigor, circulatory reactions, leukocytosis or leukopenia) were noted. Bile cultures were obtained in 56 patients with indwelling biliary drainage. RESULTS: Incidence of bacteraemia was 6.1% (3 of 49) in group A, 16% (8 of 50) in group B, but this difference is not statistically significant. The septicaemia rate was 6.1% in group A and 10% in group B (not significant). There were eleven positive blood cultures with 12 different microorganisms, Escherichia coli in four (A: n = 3). In vitro cefuroxim sensitivity was 53.3%. 25 different bacterial species were isolated from 73.2% of bile cultures, of which 53.4% were sensitive to cefuroxim and 8.2% moderately so. CONCLUSION: Although the obtained differences between the two groups were not statistically different, the reduction in bacteraemia/septicaemia rate may be of clinical use. Further studies are needed with higher dosages or antibiotic combinations to improve these results.

Adult↗
PubMed1996

Cure of gastric ulcer disease after cure of Helicobacter pylori infection--German Gastric Ulcer Study.

BACKGROUND: Helicobacter pylori infection is associated with gastric ulcer disease in about 75% of cases. OBJECTIVE: The aim of this study was to determine whether H. pylori eradication reduces gastric ulcer relapse rates. DESIGN: The study was randomized, controlled, multicentric and investigator blinded, and was conducted at three university hospitals, two teaching hospitals, and by six practising gastroenterologists. METHODS: During a period of 1 year 152 patients with gastric ulcers were randomly assigned to one of two treatment regimens: omeprazole 20 mg daily in the morning for 8 weeks (74 patients), or bismuth subsalicylate 600 mg three times daily for 8 weeks combined with 500 mg amoxicillin twice daily and 1000 mg tinidazole twice daily for the first 10 days (triple therapy) (78 patients). Follow-up examinations were performed 6, 12 and 18 months after treatment and whenever ulcer symptoms occurred. RESULTS: Of the 152 randomized patients five were excluded because of gastric cancer, 10 missed follow-up examinations and seven receiving triple therapy terminated treatment because of side effects. Of the remaining 130 patients, five of 69 (7.2%) in the omeprazole and six of 61 (9.8%) in the triple group were H. pylori negative. After 8 weeks' therapy, the gastric ulcer was healed in 85.9% (omeprazole) and in 81.8% triple) in H. pylori-positive patients, and in 80% (omeprazole) and 16.7% (triple) in H. pylori-negatives. H. pylori was eradicated in 8.1% of the patients who received omeprazole monotherapy and in 78.2% receiving triple therapy, and in 8.1% and 69.4% in an intention-to-treat analysis. The subsequent relapse rates during a follow-up period of 12 months were 50% in the omeprazole group and 4% in the triple group. Gastric ulcer relapse was observed in 49% of patients who were H. pylori positive and in 2% who were H. pylori negative after treatment. CONCLUSION: The data show that the presence of H. pylori is an important predictor of gastric ulcer relapse and that eradication of H. pylori may heal gastric ulcer disease.

Adult↗
PubMed1996

Helicobacter pylori reinfection is rare in peptic ulcer patients cured by antimicrobial therapy.

BACKGROUND: Cure of H. pylori infection in peptic ulcer patients significantly reduces the risk of ulcer recurrence. Since data on the rate of H. pylori reinfection in patients undergoing successful anti-H. pylori therapy are sparse, this study was conducted with the aim of determining the H. pylori reinfection rate in peptic ulcer patients receiving antibacterial treatment to heal their ulcer and cure H. pylori infection. METHODS: A total of 217 patients with H. pylori-associated duodenal or gastric ulcer were followed up after treatment with various antibacterial regimens resulting in histologically documented cure of H. pylori infection. Endoscopic and histological examinations were performed 4 weeks after completion of treatment and after 1, 2 and 5 years, or whenever dyspeptic symptoms occurred. To assess the H. pylori status two antral and two corpus biopsies were obtained for histological examination. RESULTS: Out of 217 patients with initially cured H. pylori infection 175 were available for endoscopic follow-up. At the time of analysis, 44 patients were re-examined after 1 year, 113 patients after 2 years and 18 patients after 5 years, giving a total of 360 patient years of follow-up. The mean duration of follow-up was 24.7 months. H. pylori reinfection was confirmed histologically in eight patients, three of whom becoming H. pylori-positive again within the first year of follow-up. Six of the eight patients with H. pylori reinfection also suffered an ulcer relapse. Eight cases of reinfection in 360 patient years represents an overall reinfection rate of 2.2%. Within the first 2 years of follow-up the reinfection rate was 0.8% per year. CONCLUSION: Our data suggest that H. pylori reinfection is rare in peptic ulcer patients receiving successful anti-H. pylori therapy. H. pylori reinfection frequently coincides with ulcer recurrence. Cure of H. pylori infection results in cure of peptic ulcer disease, provided H. pylori reinfection does not occur.

Amoxicillin↗
PubMed1996

Different expression of Helicobacter pylori gastritis in children: evidence for a specific pediatric disease?

BACKGROUND: Infection with Helicobacter pylori causes active chronic gastritis. Once the infection is acquired, gastritis will persist for almost the rest of one's life. To date, very few data are available on H. pylori gastritis in relation to age. Therefore, we attempted to investigate whether H. pylori gastritis in children exhibits features different from H. pylori gastritis in adults of two different age groups. MATERIALS AND METHODS: Fifty consecutive children with a median age of 11 years (range, 3-18 years) were compared with two groups of 50 adult patients, one group with a median age of 43 (range, 19-56 years) and another group with a median age of 70 years (range, 59-86 years). All patients had H. pylori gastritis unrelated to active peptic ulcer disease. Two biopsy specimens were taken from the antrum and two from the corpus, and the following gastritis parameters were evaluated: degree and activity of gastritis, H, pylori colonization, replacement of foveolar epithelium by regenerative epithelium, mucous depletion, presence of atrophic gastritis with intestinal metaplasia, and presence of lymphoid follicles. RESULTS: Degree and activity of gastritis, extent of H. pylori colonization, degree of replacement by regenerative epithelium, extent of mucous depletion, degree of atrophic gastritis with intestinal metaplasia, and the presence of lymphoid follicles in the antrum, as well as the presence of lymphoid follicles in the corpus differed significantly (chi-square test: p < .05). All these differences--except the once frequent occurrence of atrophic gastritis with intestinal metaplasia in adults--were attributable to a higher expression of these gastritis parameters in children. CONCLUSIONS: We conclude that H. pylori gastritis, particularly in the antrum, is more severely expressed in childhood. One reason for this might be a child-specific immune response to an infection with H. pylori. Alternatively, infection may represent a pediatric disease characterized by a nonatrophic, highly expressed form of gastritis, which changes its appearance once the host becomes adapted over time.

Adolescent↗
PubMed1996

Characterization of clinical isolates of Escherichia coli showing high levels of fluoroquinolone resistance.

During the years 1992 to 1994, an increase in fluoroquinolone-resistant Escherichia coli was observed at the Medical Center of the Technical University in Munich, Germany. Nineteen strains were collected and were thus available for further analysis. Pulsed-field gel electrophoresis showed clonal diversity in all but two strains. The majority of the patients from whom the strains were isolated had been previously treated with fluoroquinolones. Quinolone resistance was associated with mutations of the quinolone resistance-determining region of the gyrA gene in all cases. Direct sequencing of gyrA PCR amplification products revealed a mutation in codon 83 of the gyrA gene. In some instances the Ser-83-->Leu mutation was accompanied by an Asp-87-->Asn or Asp-87-->Gly mutation. Furthermore, the strains exhibited two different genotypes: in almost half of the fluoroquinolone-resistant E. coli strains as well as in the fluoroquinolone-susceptible E. coli reference strains ATCC 25922 and 35218, silent mutations were detected at bases 255, 273, 300, and 333. Although fluoroquinolones solved major problems in antimicrobial chemotherapy, in certain departments of our hospital the number of resistant E. coli isolates has become so high that susceptibility to fluoroquinolones can no longer be taken for granted.

Anti-Infective Agents↗
PubMed1996

Measles virus in otosclerosis and the specific immune response of the inner ear.

Histologic and immunohistochemical studies of otosclerotic lesions have shown that there is a chronic inflammatory reaction of the otic capsule with bone resorption resulting from vascular invasion accompanied by inflammatory cells. During the active lytic stage of otosclerosis, paramyxoviral structures have been identified by electron microscopy and measles virus antigen expression by immunohistochemistry. Recently, measles virus related sequences have been detected in tissue of otosclerotic lesions. Because the otosclerotic focus has a close relation to the perilymphatic space, the expression of measles virus antigens within it should represent an immunologic challenge to the immune system of the endolymphatic sac. In this study, measles virus specific antibodies were detected in all of the perilymph samples from 19 patients suffering from otosclerosis, and the relative amount of these IgG antibodies was much higher than in serum samples of the same patients or in perilymph of control patients. These findings support the hypothesis that measles viruses play an crucial role in the pathogenesis of otosclerosis.

Antibodies, Viral↗
PubMed1996

Severity of Helicobacter pylori gastritis predicts duodenal ulcer recurrence.

BACKGROUND: Helicobacter pylori gastritis is suggested to be the underlying condition leading to duodenal ulcer disease. The aim of the study was to investigate the relationship between chronic active H. pylori gastritis and the risk of duodenal ulcer (DU) recurrence. METHODS: One hundred and eighty-eight patients were followed up with regard to the evolution of their H. pylori gastritis after they had received antibacterial or acid-suppressing treatment for their DU. Four weeks, 1 year, and 2 years after treatment and in the case of DU recurrence several morphologic indicators of gastritis were studied histologically in the antrum and corpus. RESULTS: In patients who were cured of H. pylori infection a significant and long-lasting regression of all gastritis variables were observed. patients with persistent H. pylori infection after antibacterial treatment showed only a temporary regression of all gastritis variables. In the overall group of patients who received acid-suppressive therapy there was no change in gastritis. However, in the subgroup of patients who received omeprazole monotherapy, no change in the antrum but a statistically significant increase of gastritis in the corpus was observed. The grade of antral gastritis at the end of treatment was significantly and positively correlated with the risk of DU recurrence and was independent of the kind of pretreatment (18.5% recurrences in grade-2 versus 86% in grade-4 gastritis). CONCLUSIONS: The data show that the grade of gastritis is an important risk factor for duodenal ulcer recurrence. Cure of H. pylori infection is associated with healing of chronic H. pylori-associated gastritis. These data lend considerable support to the hypothesis that H. pylori gastritis is the most important factor among those leading to duodenal ulcer disease.

Chronic Disease↗
PubMed1996

[Prevalence of Helicobacter pylori infection in stomach carcinoma].

This report outlines the results of the first prospective case-controlled study performed within a defined geographic area of southern Germany showing a significant association between Helicobacter pylori infection and gastric carcinoma (odds ratio = 2.18, 95% confidence interval 1.04-4.56). Furthermore, it can be clearly demonstrated that no association exists between carcinoma of the gastric cardia and H. pylori infection. There is no difference in prevalence of H. pylori infection between intestinal and diffuse-type carcinoma (Lauren classification). H. pylori status determination and strain typing may be useful in identifying patient groups at risk for developing gastric carcinoma.

Adolescent↗
PubMed1995

Regression of primary gastric lymphoma of mucosa-associated lymphoid tissue type after cure of Helicobacter pylori infection. MALT Lymphoma Study Group.

Lymphoma of gastric-mucosa-associated lymphatic tissue (MALT) type has been linked to infection with Helicobacter pylori. We investigated the effect on MALT lymphoma of eradicating H pylori infection. 33 patients with primary gastric low-grade MALT lymphoma associated with H pylori gastritis were treated with omeprazole (120 mg daily) and amoxycillin (2.25 g daily) for 14 days to eradicate H pylori. In addition to histology, PCR was used to examine proliferation of monoclonal B cells before treatment and during follow-up. All patients had at least two post-treatment examinations, and all became negative for H pylori, 2 after a second treatment course. On histology, 23 (70%) patients showed complete regression and 4 (12%) partial regression of lymphoma. 6 (18%) patients had no change after cure of H pylori infection. 1 was treated with chemotherapy. Of 5 treated surgically, 4 were found to have high-grade B-cell lymphoma on histology of the resected stomach and 1 a high-grade T-cell lymphoma. PCR showed complete disappearance of monoclonal B cells after cure of H pylori infection in 13 of 16 patients investigated. During median follow-up of 1 year no relapse of MALT lymphoma occurred. Low-grade primary gastric MALT lymphoma can completely regress after eradication of H pylori infection. However, longer follow-up is needed to clarify whether the remission is lasting.

Adult↗
PubMed1995

Frequency of toxic shock syndrome toxin- and enterotoxin-producing clinical isolates of Staphylococcus aureus.

In 183 clinical isolates of Staphylococcus aureus, toxic shock syndrome toxin was detected in 13.7%, enterotoxin A in 20.2%, enterotoxin B in 7.7%, enterotoxin C in 5.5% and enterotoxin D in 3.3%. Seventy-three (39.9%) of the strains were found to produce one or more toxins. Multiple secretion of toxins was rare (< 1% of all strains) except for the combinations enterotoxin A with toxic shock syndrome toxin and enterotoxin A with enterotoxin D. These combinations were observed at significantly higher frequencies (4.9% and 2.2%, respectively) than would have been expected from values calculated from respective individual frequencies (0.88% and 0.06%) (p < 0.0001). In comparison with Staphylococcus aureus strains isolated from miscellaneous material, Staphylococcus aureus blood culture isolates produced enterotoxin D in significantly larger amounts and at higher frequencies (p = 0.01 in both cases). These toxins might play an important pathogenic role in Staphylococcus aureus infections.

Bacterial Toxins↗
PubMed1995

Recurrence of duodenal ulcers during five years of follow-up after cure of Helicobacter pylori infection.

BACKGROUND: Chronic Helicobacter pylori-associated gastritis is now widely accepted as one of the most important pathogenic factors in duodenal ulcer disease. However, little is known about for how long patients remain free of duodenal ulcer relapses after H. pylori infection has been cured. In the present study, we investigated remission time during a 5-year follow-up period after anti-H. pylori treatment. METHODS: The patients were randomly allocated to treatment with either a combination of 3 x 600 mg bismuth subsalicylate and 2 x 1000 mg amoxycillin or 3 x 600 mg bismuth subsalicylate monotherapy. Endoscopy, including histological and microbiological examination of biopsies, was performed 4 weeks after termination of treatment and after 1 and 2 years. During the third, fourth and fifth years of the follow-up period, patients were monitored twice a year for symptoms compatible with ulcer relapse and for their use of anti-ulcer medication. Endoscopic and histological examinations were carried out whenever symptoms occurred. RESULTS: Of 56 evaluated patients, 47 showed healing of ulcers after bismuth subsalicylate plus amoxycillin compared with 44 of 57 after bismuth subsalicylate monotherapy. H. pylori infection was cured in 52% (29 of 56) of the patients after combined therapy and in 4% (2 of 57) after the monotherapy. The cumulative duodenal ulcer relapse rates after 5 years were 38% (18 of 47) after the combined therapy and 75% (33 of 44) after the monotherapy. In patients who were cured of H. pylori infection, the cumulative duodenal ulcer relapse rate after 5 years was 9.7% (3 of 31), compared with 81.7% (49 of 60) in those patients who remained H. pylori-positive after treatment (P < 0.001). In two of the three patients who suffered duodenal ulcer relapse after being cured of H. pylori infection, H. pylori was present again at the time of relapse. CONCLUSION: The data suggest that curing H. pylori infection results in long-term cure of duodenal ulcer disease and that duodenal ulcer relapses in successfully treated patients are most often associated with H. pylori reinfection.

Adolescent↗
PubMed1995

Expression of adhesion molecules on human granulocytes after stimulation with Helicobacter pylori membrane proteins: comparison with membrane proteins from other bacteria.

Type B gastritis in its active form is characterized by a dense infiltration of the lamina propria with granulocytes. Since the bacterium Helicobacter pylori does not invade the epithelial barrier, a signaling pathway chemoattractive for granulocytes must exist across this mucosal boarder. One possible mechanism tested was whether granulocytes are directly activated by water-soluble membrane proteins (WSP) from H. pylori. These findings were compared with the effects of WSP from other bacteria (Helicobacter felis, Campylobacter jejuni, Escherichia coli, and Staphylococcus aureus). A unique activation pattern by H. pylori WSP was found. Like all other WSP tested, they induced an upregulation of CD11b but had no influence on CD11c and, most strikingly, CD62L expression. In contrast, E. coli WSP, e.g., not only induce a strong CD11b and CD11c expression but also lead to a loss in surface CD62L. The lack of CD62L shedding conserves rolling of granulocytes along the endothelium, creating a favorable precondition for granulocytes to stick more readily to activated endothelium after H. pylori stimulation via CD11b-CD54 receptor-counterreceptor interaction. This may explain why H. pylori infection is a very strong stimulus for granulocyte infiltration. The active fraction for the induction of CD11b on granulocytes is a heat- and protease-sensitive protein with a molecular mass between 30 and 100 kDa. One activation step involved may be the binding of WSP to CD15 determinants on granulocytes with subsequent induction of CD11b.

Antigens, Bacterial↗