Comparison of transnasal small-caliber vs. peroral conventional esophagogastroduodenoscopy for evaluating varices in unsedated cirrhotic patients.

BACKGROUND AND STUDY AIMS: We aimed to evaluate the accuracy of transnasal small-caliber esophagogastroduodenoscopy (TNSC-EGD) compared with peroral conventional EGD (POC-EGD) for evaluating varices in unsedated patients with liver cirrhosis. The success rate, safety, endoscopist satisfaction, and patient tolerability of TNSC-EGD were also addressed. PATIENTS AND METHODS: One hundred patients with liver cirrhosis participated in this randomized crossover trial, and 84 subjects completed both procedures. Of the 84 patients, 28 had marked bleeding diathesis (platelet count ≤ 50000/mm (3) and/or prothrombin time ≥ 1.7 INR). Endoscopists and patients answered questionnaires using a 100-mm visual analog scale about, respectively, their satisfaction and their tolerance of the procedure. RESULTS: The success rate of TNSC-EGD was comparable to that of POC-EGD (96% vs. 99%). Nasal mucosal hemorrhages induced by TNSC-EGD occurred in 5 patients (6%), but were easily controlled. Compared to the POC-EGD reference test, diagnostic accuracies of TNSC-EGD for detecting esophageal varices, gastric varices, and red color signs were 98%, 98%, and 96%, respectively. Concordance rates on grading esophageal varices and gastric varices were excellent at 93% (κ = 0.85) and 96% (κ = 0.87). Endoscopist satisfaction was not significantly different between TNSC-EGD and POC-EGD, whereas patient tolerance of TNSC-EGD was significantly greater than that of POC-EGD (79.0 ± 14.4 vs. 69.5 ± 16.1; P = 0.001). CONCLUSION: TNSC-EGD without sedation was found to be feasible, safe, and accurate for evaluating esophageal varices, gastric varices, and red color signs in patients with cirrhosis - even in those with marked bleeding diathesis. Furthermore, it was significantly better tolerated by patients, without altering endoscopist satisfaction. Our findings indicate that TNSC-EGD without sedation might be viewed as a potential alternative to POC-EGD for evaluation of varices.

Invasiveness of Helicobacter pylori into human gastric mucosa.

BACKGROUND: Helicobacter pylori has generally been observed only in the gastric mucous layer or in the spaces between gastric mucus-secreting cells and not in the gastric epithelial cells or in the lamina propria. The purpose of this study is to determine whether H. pylori invades the gastric mucosa, using an immunoelectron microscopical examination of human gastric mucosa infected with H. pylori. MATERIALS AND METHODS: Five hundred gastric antral biopsy specimens were fixed in a periodate-lysin-paraformaldehyde solution, embedded in Lowicryl, sectioned, and examined with a light microscope. One hundred specimens moderately or severely infected with H. pylori were selected and were incubated with polyclonal rabbit anti-H. pylori antibody. The specimens were washed, incubated with 20 nm of colloidal gold-conjugated goat anti-rabbit IgG, stained with uranyl acetate and lead citrate, and observed with a transmission electron microscope. RESULTS: In one case, a bacterium was observed within the cytoplasm of a gastric mucus-secreting cell; in another case, a few bacteria were observed within the cytoplasm of a stromal cell in the lamina propria. The bacteria could be differentiated from degenerated intracellular organelles by gold particles attached to the bacteria. CONCLUSION: H. pylori rarely invade the lamina propria and gastric cells.

Comparison of Helicobacter pylori infection between Fukuoka, Japan and Chinju, Korea.

BACKGROUND: Helicobacter pylori is the causative agent of type B chronic gastritis, and plays a major role in the pathogenesis of gastroduodenal ulcer and gastric cancer. Because gastric cancer has been the leading cause of cancer mortality in Japan and Korea, we conducted a seroepidemiological study to estimate the prevalence of H. pylori infection in Japan and Korea in order to explain the current change in the gastric cancer incidences between two countries. MATERIALS AND METHODS: Samples used for this study included 1204 sera from Chinju, Korea and 580 sera from Fukuoka, Japan. Immunoblotting, using a sonicated crude H. pylori antigen and 1:5 dilution of serum, was performed, considering the immunoblot shows reactivity to the 120 Kd antigen of H. pylori as a specific marker of H. pylori infection. RESULTS: Seroepidemiology data from Fukuoka, Japan showed a prevalence of H. pylori infection of 20% before school age, 40% by teenage years, and over 80% beyond 20 years of age. Seroepidemiology data from Chinju, Korea, showed a 50% infection rate in preschool ages, and over 80% prevalence rate after 7 years of age. CONCLUSIONS: Lower rates of childhood H. pylori infection in Fukuoka may explain the recent decline and shift in the incidence of stomach cancer in Japan, supporting the hypothesis that H. pylori is a major determinant in the pathogenesis of stomach cancer.

Monoclonal antibodies against Helicobacter pylori cross-react with human tissue.

BACKGROUND: H. pylori is a causative agent of chronic gastritis. However, the pathogenic mechanism by which H. pylori induces chronic inflammation and epithelial injuries in the gastric and duodenal mucosa is not well known. Investigators have recently reported that some monoclonal antibodies against H. pylori cross-react with the gastric epithelial cells. So, there exists the possibility that the autoimmune mechanism may be involved in the pathogenesis of chronic gastritis caused by H. pylori. The purpose of his study is to investigate whether the antibodies against H. pylori react with human tissues or not, using a large panel of monoclonal antibodies. MATERIALS AND METHODS: Two hundred and fourteen monoclonal antibodies against H. pylori were produced. An immunohistochemical staining of human tissues, including H. pylori-infected gastric mucosa, was performed using the antibodies. RESULTS: Of 214 monoclonal antibodies, 71 antibodies reacted with H. pylori in the gastric mucosa. Of 71 antibodies, 25 antibodies also reacted with gastric epithelial cells, 11 antibodies reacted with ductal cells of the salivary gland, 11 antibodies reacted with renal tubular cells, and 8 antibodies reacted with duodenal epithelial cells. The antibodies which showed cross-reactivity with gastric epithelial cells included those against urease, flagella, lipopolysaccharide, and heat shock protein of H. pylori. CONCLUSIONS: It is believed that the autoimmune reaction might be involved in the pathogenesis of chronic gastritis due to H. pylori infection, and that the autoimmune reaction induced by H. pylori infection might also be involved in the pathogenesis of various diseases in other organs.

Pathogenesis and prevention of stomach cancer.

In many Western developed countries, the incidence of stomach cancer has declined dramatically. This decrease was an extraordinary, "unplanned triumph", especially when compared to other cancers. Stomach cancer is still the most prevalent malignant tumor in Korea. Most Koreans carry Helicobacter pylori in their stomach. Thus, a new hypothesis, based on the relationship between the host and Helicobacter pylori, is presented as the carcinogenesis of human stomach cancer. The reasons for why the N-nitrosamide hypothesis should be dismissed as the etiology of stomach cancer, and why the contemporarily available principles and practice of intervention strategies to rapidly decrease the surprisingly high prevalence rate of Helicobacter pylori infection are impractical at this moment, are explained. In order to introduce an alternative provisional strategy of the "planned triumph" for the population vulnerable to stomach cancer, vitamin C is defined as an anti-inflammatory agent on the basis of the pathogenesis of Helicobacter pylori infection.

Increased oxidative DNA damage in Helicobacter pylori-infected human gastric mucosa.

Helicobacter pylori causes type B gastritis. It shows strong association with the development of gastric carcinoma. A plausible hypothesis for the missing link between H. pylori infection and gastric carcinogenesis involves oxygen free radical-induced DNA damage. To test this hypothesis, we compared the amount of 9-hydroxydeoxyguanosine, a marker for oxygen free radical-induced DNA damage, in the DNA of human gastric mucosa with and without H. pylori infection. Gastric antral biopsies were taken from pediatric patients and volunteers to select H. pylori-positive and H. pylori-negative specimens. The 8-hydroxydeoxyguanosine content of the gastric mucosal DNA was measured after H. pylori-positive and H. pylori-negative volunteers were identified. The increased level of oxidative DNA damage suggests the mechanistic link between H. pylori infection and gastric carcinoma.

Individualized surgical management of complete atrioventricular canal.

In a 5 year interval 46 children with complete atrioventricular canal (CAVC) required 51 operations. Thirty-two children underwent correction; nine received surgical palliation. The ages of the children undergoing correction ranged from 4 months to 14.6 years (mean 4.2 years); eight were less than 1 year old. Weights ranged from 4.1 kg to 39 kg (mean 13.5 kg); 15 weighted less than 10 kg. Ten had undergone previous palliation (seven by pulmonary artery band; three by shunt). There were no early deaths and two late deaths. One infant required mitral replacement at correction; two required subsequent mitral replacement. The ages of the children undergoing palliation ranged from 8 days to 1.34 years (mean 5.8 months); 16 were less than 1 year old. Weights ranged from 2.5 kg to 8.5 kg (mean 4.4 kg); 14 weighted less than 5 kg. Operations included pulmonary artery banding in 14, shunt creation in four, and pericardial enlargement of the right ventricular outflow tract in one. One death occurred 5 days after pulmonary artery banding in an infant with unrecognized coarctation. One late death occurred several months after the creation of a second shunt in a child with severe tetralogy of Fallot and hypoplastic pulmonary arteries. Forty-two (91%) of these children were alive at the time of this review. The outcome in these 46 patients supports individualized choice of initial operation (palliation versus correction) based upon clinical condition, weight, and associated anomalies. The pulmonary artery is banded in infants less than 4 to 5 kg; larger infants and children undergo correction primarily.