Hemodynamic abnormalities in the left atrial appendage in patients with paroxysmal atrial fibrillation, with special reference to albumin-contrast echocardiographic aspects.

AIM: We assessed the prolonged dysfunction of the left atrial appendage caused by paroxysmal atrial fibrillation. METHODS AND RESULTS: Transesophageal echocardiography with intravenous albumin-microspheres (Albunex, 0.2 ml/kg) was performed in 100 consecutive patients (44 patients in sinus rhythm without previous paroxysmal atrial fibrillation: 13 patients in sinus rhythm who had had previous episodes of paroxysmal atrial fibrillation; and 43 patients with sustained atrial fibrillation). We compared the left atrial appendage ejection fraction and degree of opacification in the left atrial appendage with Albunex in the groups. Patients with previous paroxysmal atrial fibrillation had lower left atrial appendage ejection fractions than patients in sinus rhythm without paroxysmal atrial fibrillation (33 +/- 14 vs. 47 +/- 14%, p < 0.001). More than half of the patients (7/13 [54%]) with previous paroxysmal atrial fibrillation showed delayed and incomplete opacification of the left atrial appendage with Albunex. CONCLUSION: We conclude that paroxysmal atrial fibrillation causes left atrial appendage stunning, at least in some patients.

Profile of Helicobacter pylori cytotoxin derived from two areas of Japan with different prevalence of atrophic gastritis.

BACKGROUND AND AIM: To clarify the roles of Helicobacter pylori cytotoxin in gastric atrophy, the cytotoxin positive rate and cytotoxin activity in Fukui and Okinawa, where the prevalence of atrophic gastritis and gastric cancer risk are quite different, were studied. MATERIALS: Seventy three strains from Fukui and 51 from Okinawa were examined. METHODS: The validation of atrophy was done by endoscopy, being confirmed with histology. The supernatant of liquid H pylori culture media was concentrated 20-fold, serially diluted, using doubling dilutions, and scored from 1 to 8. The semi-quantitated cytotoxin activity was expressed as the maximum dilution score yielding > 50% A431 cell vacuolation, being standardised with bacterial density. RESULTS: The cytotoxin activity of the strains from Fukui was highly diverse compared with that from Okinawa, although the cytotoxin positive rate was not different. In Fukui strains, the grade of atrophy and the cytotoxin activity were correlated (p < 0.05). In addition, the cytotoxin activity of the strains from all patients in Okinawa, most of whom showed closed-type/mild atrophy, was significantly lower than that of the strains from the patients with open-type/severe atrophy in Fukui (6.46 (5.53) v 9.76 (8.80), p < 0.05), (mean (SEM)). CONCLUSION: The difference in profile of the cytotoxin activity in the two areas was related to the difference in the prevalence of atrophic gastritis.

Cytotoxin and urease activities of Helicobacter pylori isolates from Japanese patients with atrophic gastritis or duodenal ulcer.

The vacuolating cytotoxin and urease secreted by Helicobacter pylori are thought to be virulent factors. Because vacuolation is potentiated by the presence of ammonium ion, which is produced by urease in vitro, it is of interest to examine whether cytotoxin and urease work reciprocally in the development of atrophic gastritis or duodenal ulcer. In the present study, patients (all H. pylori-positive) were divided into four groups: mild atrophic gastritis (group 1; nine patients), severe atrophic gastritis (group 2; 36 patients), duodenal ulcer with mild atrophic gastritis (group 3; 19 patients) and duodenal ulcer with severe atrophic gastritis (group 4; 12 patients). Cytotoxin production and urease activity of H. pylori isolated from these patients were analysed. Cytotoxin production was observed in four of nine (44.4%), 28 of 36 (77.8%), 11 of 19 (57.9%) and eight of 12 (66.7%) isolates from groups 1, 2, 3 and 4, respectively. Cytotoxin-producing H. pylori isolates were found significantly more in patients with severe atrophy than in patients with mild atrophy (P = 0.048). The mean of relative activity of cytotoxin in H. pylori isolate was 1.6 +/- 2.3, 7.9 +/- 7.4, 5.8 +/- 6.0 and 9.0 +/- 9.1 in groups 1, 2, 3 and 4, respectively. Helicobacter pylori isolates from severe atrophy or duodenal ulcer patients in groups 2 or 4 possessed significantly higher activity than those from non-ulcer patients in group 1 (P = 0.017 and 0.030, respectively). The mean of urease activity was 8.6 +/- 4.6, 10.0 +/- 5.9, 10.0 +/- 8.5 and 11.2 +/- 7.7 IU/mg in groups 1, 2, 3 and 4, respectively. These differences indicated no statistical significance. In each H. pylori isolate, the production of cytotoxin and urease were independent, which indicated that there was no reciprocal effect between them in vivo. Thus, cytotoxin-producing H. pylori isolates were more prevalent in patients with severe atrophic gastritis and the cytotoxin activities of H. pylori isolates from the patients with severe atrophic gastritis or duodenal ulcer were much higher than those from the patients with mild atrophic gastritis, which suggested that vacuolating cytotoxin may be a disease-inducing factor.

Differences in urease activity in live Helicobacter pylori cultured from patients with gastroduodenal diseases.

AIM: To develop a reliable method for measuring urease activity in live bacteria, and to determine whether there are any differences in urease activity among the Helicobacter pylori strains involved in gastroduodenal disease. DESIGN: The stability of the method was examined in the first phase of the study, and in a second phase the mean urease activity in clinical isolates from different groups of patients was compared. MATERIALS AND METHODS: To assess the stability and reliability of the method, we assessed the relationship between bacterial proliferation and urease activity, the relationship between the number of bacteria and the optical density, and differences in urease activity among bacterial generations. Ten of the 3-day-old colonies in the third generation were suspended in phosphate-buffered saline, and urease activity was measured as 10(5) colony-forming units/ml bacteria. RESULTS: The assay system appeared to be effective, because the urease activity of live bacteria in the logarithmic growth period was constant, the number of bacteria and the optical density showed a linear correlation on a bilogarithmic graph and there was no significant difference in urease activity over three generations. With this method, urease activity varied from 0.192 to 80.42 mIU/10(5) colony-forming units of bacteria/ml. There was no significant difference in the mean urease activity of live bacteria from controls, gastric ulcer patients and duodenal ulcer patients. However, the mean urease activity in bacteria from cancer patients was significantly higher than that of controls or duodenal ulcer patients. CONCLUSIONS: H. pylori strains derived from cancer patients, which have relatively high levels of urease activity, might easily colonize the stomach and lead to much mucosal damage during the long course of H. pylori infection.

Vacuolating cytotoxin production by Helicobacter pylori isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients.

OBJECTIVE: We investigated the production of vacuolating cytotoxin by Helicobacter pylori isolates from patients with peptic ulcer, atrophic gastritis or gastric carcinoma in order to examine the pathophysiological significance of vacuolating cytotoxin in these diseases. METHODS: H. pylori was isolated from 18 patients (five with peptic ulcers, seven with atrophic gastritis and six with gastric carcinoma). Culture supernatants of H. pylori isolates, concentrated 20-fold, were serially diluted and then analyzed for cytotoxin activity semi-quantitatively using A431 cells as indicator cells. The relative activity of vacuolating cytotoxin was defined according to the maximum dilution. RESULTS: Cytotoxin production was observed in two out of five, six out of seven and six out of six isolates from peptic ulcer, atrophic gastritis and gastric carcinoma patients, respectively. The mean relative activity was calculated as 0.80, 2.71 and 2.50 in CONCLUSION: These results suggest that vacuolating cytotoxin-producing H. pylori is strongly associated with both atrophic gastritis and gastric carcinoma.

Fate of orally administered triethylenetetramine dihydrochloride: a therapeutic drug for Wilson's disease.

Triethylenetetramine dihydrochloride (TETA) is a therapeutic drug for Wilson's disease. We developed a simple fluorometric method for detection of TETA in biological fluids by using high-performance liquid chromatography (HPLC), and examined TETA concentrations in the serum and urine of two healthy adults who were given TETA orally. No TETA peak was detected in the serum. The amount of TETA in the urine of the two adults was only 1.6 and 1.7% of the dose administered. However, a large unidentified peak appeared in the urine after oral administration. This peak was not observed in a mixture of TETA and control urine or in urine before TETA administration. When the urine after TETA administration was analyzed after hydrolysis with HCl, the unidentified peak disappeared, while the TETA peak increased. These findings indicate that the substance which yielded the unidentified peak is a metabolite of TETA, suggesting that most of the TETA administered is metabolized and then excreted in the urine.

[Mucosubstance and lectin histochemistry of DMH induced colonic tumor in rats].

Histo-pathological appearances of DMH-induced colonic tumor in Wistar rats were sequentially observed upto the 35th week after the drug administration. In our series, 28 tumors were successfully induced in the colonic mucosa of 19 out of 64 rats treated with DMH, and they were histologically diagnosed as adenocarcinoma. However, there were differences in the histo-pathological findings of the carcinoma between the distal colon and the proximal colon in rats. That is, the slowly growing type of well differentiated adenocarcinoma was likely to originate from the proper mucosa in the distal colon, while in the proximal colon the rapidly growing type of tumor did from atypical glands in the lymphoid follicles. Therefore, it was suggested that histogenesis and growing processes of the carcinoma were differed in the distal colon from that in the proximal colon in rats. Second, epithelial mucosubstances and lectin-binding properties of these lesions were examined histochemically. There were differences in the lectin-binding patterns of UEA-I and PNA between carcinomas and/or atypical glands in the lymphoid follicle and normal background mucosa in rat colon. In the UEA-I staining, almost all tumors were positively stained except for one case, and in the well differentiated type a positive staining was discernible at the cell apex and secretory product in tumors, while in the undifferentiated type, it was seen at the cytoplasma and secretory product. From these histopathological and histochemical studies it may be concluded that these lectins is likely to be useful as tumor markers for the large bowel, and also effective for a diagnosis of minute carcinoma in the large bowel.