Deficiency of the complex I of the mitochondrial respiratory chain but improved adenylate control over succinate-dependent respiration are human gastric cancer-specific phenomena.

The purpose of study was to comparatively characterize the oxidative phosphorylation (OXPHOS) and function of respiratory chain in mitochondria in human gastric corpus mucosa undergoing transition from normal to cancer states and in human gastric cancer cell lines, MKN28 and MKN45. The tissue samples taken by endobiopsy and the cells were permeabilized by saponin treatment to assess mitochondrial function in situ by high-resolution oxygraphy. Compared to the control group of endobiopsy samples, the maximal capacity of OXPHOS in the cancer group was almost twice lower. The respiratory chain complex I-dependent respiration, normalized to complex II-dependent respiration, was reduced that suggests deficiency of complex I, but the respiratory control by ADP in the presence of succinate was increased. Similar changes were observed also in mucosa adjacent to cancer tissue. The respiratory capacity of MKN45 cells was higher than that of MKN28 cells, but both types of cells exhibited a deficiency of complex I of the respiratory chain which appears to be an intrinsic property of the cancer cells. In conclusion, human gastric cancer is associated with decreased respiratory capacity, deficiency of the respiratory complex I of mitochondria, and improved coupling of succinate oxidation to phosphorylation in tumor tissue and adjacent atrophic mucosa. Detection of these changes in endobiopsy samples may be of diagnostic value.

Giant peptic ulcer hemorrhages: epidemiology, treatment, and outcome in the teaching hospital of Tartu.

UNLABELLED: The aim of the study was to analyze the management and outcome in the case of giant peptic ulcer hemorrhage (GPUH). MATERIAL AND METHODS: We analyzed the data of all 372 cases of 348 patients treated for acute peptic ulcer hemorrhage during 2005-2007. The source and intensity of hemorrhage was assessed endoscopically according to the Forrest classification: class I+II, persistent hemorrhage or signs of recent hemorrhage; and class III, ulcer without signs of recent hemorrhage. Of the 372 cases, 64 (17%) were GPUH (diameter, ≥2 cm) (group 1) and the remaining 308 (83%) were peptic ulcer hemorrhages of a standard size (SPUH) (diameter, <2 cm), which formed the control group (group 2). RESULTS: Forrest class I+II hemorrhage occurred significantly more frequently in the group 1 as compared with the group 2 (97% [62/64] vs. 77% [238/308]), as well as endoscopic hemostasis, (80% [51/64] vs. 57% [175/308]), repeat hemostasis procedures (22% [11/51] vs 6.3% [11/175]), and operative treatment (27.6% [16/58] vs 1.7% [5/290]) were needed more frequently in the group 1. No postoperative in-hospital deaths occurred in either group. Five patients died: 2 (3.4% [2/58]) in the group 1 and 3 (1.0% [3/290]) in the group 2. CONCLUSIONS: GPUHs were more intensive as compared with SPUHs and needed more endoscopic hemostasis, including repeat procedures and operative treatment. Endoscopic hemostasis and operative treatment allowed reducing mortality due to GPUH to 3.4%.

Changes in the histology and function of gastric mucosa and in Helicobacter pylori colonization during a long-term follow-up period after vagotomy in duodenal ulcer patients.

BACKGROUND/AIMS: To investigate changes in the histology and the Helicobacter pylori (H. pylori) prevalence and density of the gastric mucosa, as well as in fasting serum gastrin and serum pepsinogen I, depending on completeness of vagotomy, and in cases of recurrent ulcer, during 14 years after operation in duodenal ulcer patients. METHODOLOGY: 122 vagotomized duodenal ulcer patients were studied twice on average 9 and 14 years after operation. The presence of recurrent ulcer and completeness of vagotomy were assessed simultaneously endoscopically and by endoscopic Congo red test. The histology of the gastric antrum and corpus mucosa was assessed in accordance with the Sydney system. The amount of H. pylori in the specimens was detected by microscopic counting; gastrin and pepsinogen I in serum were determined radioimmunologically. RESULTS: During the 14-year follow-up period, complete vagotomy patients were characterized by a smaller amount of active antrum gastritis and a larger amount of active chronic corpus gastritis involving corpus atrophy in 46% of cases 14 years after operation. Recurrent ulcer patients were characterized by a significantly higher prevalence of high-grade H. pylori colonization and active mucosal inflammation in the antrum as well as by a lower level of active mucosal inflammation and atrophy in the corpus and a higher serum pepsinogen I level compared with complete vagotomy cases. The data of incomplete vagotomy patients without recurrent ulcer became more similar to those recorded for recurrent ulcer patients. CONCLUSIONS: In duodenal ulcer patients, changes in the histology of the gastric antrum and corpus mucosa as well as in H. pylori prevalence and density and in serum pepsinogen I levels are different depending on completeness of vagotomy during 14 years after operation.

Persistence of Helicobacter pylori infection in patients with peptic ulcer perforation.

OBJECTIVE: In patients with perforated peptic ulcer (PPU) the convergence between the high eradication rate of Helicobacter pylori infection and low rates of ulcer relapse after treatment has been associated with reinfection by non-virulent strains. The objective of this study was to evaluate the persistence of infection by virulent H. pylori strains and ulcer recurrence in 33 patients with PPU one year after surgery and antimicrobial treatment. MATERIAL AND METHODS: The histological evaluation and molecular detection of H. pylori cagA and ureA genes, vacA allelic types and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the glmM gene products from antral mucosa specimens were performed initially, 2-5 months and 1 year after therapy. RESULTS: The density of H. pylori colonization was temporarily decreased (p<0.05) 2-5 months after therapy. After one year, complete eradication was achieved in only 7 patients (23%) at histological examination and recurrent ulcers were found in 3/33 (9%) patients. The vacA s1a allelic type of cagA-positive strains persisted in 19/33 (58%) PPU patients with identical PCR-RFLP fingerprints in 8/9 (89%) of the patients. CONCLUSIONS: In PPU patients with a low eradication rate of H. pylori infection after surgical and antimicrobial treatment, the frequent recrudescence of the infection is mostly caused by the persisting virulent strains of the cagA and vacA s1a subtypes. In the 1-year follow-up period the recurrent ulceration can be postponed just by the lowered colonization density of H. pylori after eradicative therapy.

Oxidative phosphorylation and its coupling to mitochondrial creatine and adenylate kinases in human gastric mucosa.

Energy metabolism in gastrobiopsy specimens of the antral and corpus mucosa, treated with saponin to permeabilize the cells, was studied in patients with gastric diseases. The results show twice lower oxidative capacity in the antral mucosa than in the corpus mucosa and the relative deficiency of antral mitochondria in complex I. The mucosal cells expressed mitochondrial and cytosolic isoforms of creatine kinase and adenylate kinase (AK). Creatine (20 mM) and AMP (2 mM) markedly stimulated mitochondrial respiration in the presence of submaximal ADP or ATP concentrations, and creatine reduced apparent Km for ADP in stimulation of respiration, which indicates the functional coupling of mitochondrial kinases to oxidative phosphorylation. Addition of exogenous cytochrome c increased ADP-dependent respiration, and the large-scale cytochrome c effect (>or=20%) was associated with suppressed stimulation of respiration by creatine and AMP in the mucosal preparations. These results point to the impaired mitochondrial outer membrane, probably attributed to the pathogenic effects of Helicobacter pylori. Compared with the corpus mucosa, the antral mucosa exhibited greater sensitivity to such type of injury as the prevalence of the large-scale cytochrome c effect was twice higher among the latter specimens. Active chronic gastritis was associated with decreased respiratory capacity of the corpus mucosa but with its increase in the antral mucosa. In conclusion, human gastric mucosal cells express the mitochondrial and cytosolic isoforms of CK and AK participating in intracellular energy transfer systems. Gastric mucosa disease is associated with the altered functions of these systems and oxidative phosphorylation.