Gastric mucosal density of Helicobacter pylori estimated by real-time PCR compared with results of urea breath test and histological grading

The accuracy of the urea breath test (UBT) and histological grading for estimation of the density of Helicobacter pylori in gastric mucosa is not known. Real-time (TaqMan) PCR was used to estimate the total number of H. pylori genomes in biopsy samples. These values were compared with those obtained by the UBT and the histological grade obtained by the Sydney system. The UBT and endoscopy with antral and corporal biopsies were performed in 88 consecutive untreated patients with dyspepsia. Bacterial culture and the rapid urease test were done with fresh biopsy materials. TaqMan PCR and histological examination were done on serial paraffin sections of the biopsy samples. Of the five methods tested, TaqMan PCR had the highest sensitivity and specificity (both 100%) in the diagnosis of H. pylori infection. The mean density of H. pylori genomes for pairs of biopsy samples from individual patients was compared with the individual values obtained by the UBT; correlation between the results was significant. The density of H. pylori genomes was higher in histological grades 1, 2 and 3 than in grade 0, without significant differences between adjacent grades from 1 to 3. These results suggest that the severity of H. pylori infection of the stomach can be estimated by the UBT and that histopathologists might state whether the organism is present or absent, rather than making a quantitative statement as recommended in the Sydney system.     

Local immune response in Helicobacter pylori-infected cats and identification of H. pylori in saliva, gastric fluid and faeces.

Helicobacter pylori-infected cats were screened by culture and polymerase chain reaction (PCR) for the presence of H. pylori in salivary secretions, gastric juice, gastric tissue and faeces. H. pylori was cultured from salivary secretions in six of 12 (50%) cats and from gastric fluid samples in 11 of 12 (91%) cats. A 298 base pair polymerase chain reactions (PCR) product specific for an H. pylori 26000 MW surface protein was amplified from dental plaque samples from five of 12 (42%) cats and from the faeces of four of five (80%) cats studied. Analyses of serum and mucosal secretions by enzyme-linked immunosorbent assay (ELISA) revealed an H. pylori-specific immunoglobulin G (IgG) response, and elevated IgA anti-H. pylori antibody levels in salivary and local gastric secretions. Immunohistochemical analyses of gastric tissue revealed the presence of IgM+ B cells assembled into multiple lymphoid follicles surrounded by clusters of CD4+ and CD8+ T cells. The lamina propria also contained single cells or aggregates of IgA+ and IgM+ B cells. These observations show that H. pylori can be identified in feline mucosal secretions, and that a localized IgA immune response develops in gastric tissue of H. pylori-infected cats. The findings suggest a zoonotic risk from exposure to personnel handling H. pylori-infected cats in vivaria.     

Validation of string test for diagnosis of Helicobacter pylori infections

The method of recovering Helicobacter pylori DNA or viable cells absorbed on a string that a person has swallowed and that is retrieved an hour later (string test) should be a useful alternative to traditional analysis of cells or DNA obtained by endoscopy, which is invasive, uncomfortable, relatively costly, and ill-suited for community-based and pediatric studies. Here we assayed the sensitivity and validity of the string test versus conventional endoscopic biopsy for detecting and analyzing H. pylori infection. Forty-four people with gastric complaints were studied using both H. pylori culture and urease gene (ureB) PCR. H. pylori organisms cultured from strings and biopsy specimens from the same patients were fingerprinted by the randomly amplified polymorphic DNA (RAPD) method. Biopsy sections were also hematoxylin and eosin and silver stained for H. pylori detection. H. pylori was cultured from 80% of strings and detected by PCR from 91% of strings from participants whose biopsies had been H. pylori positive by culture, PCR, and/or histology. Strains recovered from strings and biopsy specimens yielded identical or closely related RAPD profiles in each of the 24 cases tested. We conclude that the string test is a useful method for H. pylori recovery and analysis when relatively noninvasive procedures are needed.     

Usefulness of antimicrobial susceptibility in the eradication of Helicobacter pylori

The rate of eradication of Helicobacter pylori with standard triple therapy using omeprazole, amoxicillin and clarithromycin (OAC) is unacceptable in populations with high rates of clarithromycin resistance (15–20%). The aim of this study was to compare the efficacy of 10-day OAC therapy as the first-line treatment in patients diagnosed by culture with antimicrobial susceptibility or diagnosed by a ¹³C-labelled urea breath test (UBT) without antimicrobial susceptibility in an area where the clarithromycin resistance rate was 15–20%. This was a retrospective cohort study of 266 patients, recruited consecutively throughout 2008. A total of 247 H. pylori-infected patients received antibiotic therapy (221 received the 10-day OAC therapy and 26 received other regimens) of which 134 patients were diagnosed by culture of gastric samples followed by antimicrobial susceptibility testing and 113 were diagnosed by UBT. In all patients, the eradication of H. pylori was checked by UBT. The cost of eradication by 10-day OAC treatment was assessed in each patient. The success rate of 10-day OAC therapy in patients diagnosed by culture and by UBT was 88% (103/117) and 49% (51/104), respectively (p <0.0005). The treatment was also more cost-effective in the former of these two groups (€571 versus €666). To perform culture and antimicrobial susceptibility of the H. pylori isolates was a more successful and cost effective strategy than empirical 10-day OAC treatment in populations with high rates of resistance to clarithromycin.     

Clinical impact of preoperative screening for gastric mucin secretion in cervical discharge by HIK1083-labeled latex agglutination test

The present study evaluated the clinical impact of preoperative screening for gastric mucin in cervical discharge, using a latex agglutination test with HIK1083, a monoclonal antibody against gastric mucin. HIK1083-labeled latex agglutination tests were performed preoperatively using cervical secretions from 44 patients (group 1) with profuse watery vaginal discharge, multiple cervical cysts on vaginal ultrasonography, or yellowish mucin on a Papanicolaou smear and from 31 patients (group 2) with none of these clinical signs. The results were positive in 26 patients in group 1 and in no patients in group 2. Glandular lesions with a gastric phenotype were identified histologically in all 26 cases positive for the HIK1083 latex test, such as minimal deviation adenocarcinoma, lobular endocervical glandular hyperplasia (LEGH), and pyloric gland metaplasia, but not in negative cases. In 2 cases of LEGH, adenocarcinoma in situ was identified. Screening of gastric mucin in cervical discharge may facilitate preoperative detection of some early cervical adenocarcinoma.     

Evaluation of a rapid agglutination test for detection of group B streptococci in the gastric aspirates of neonates

A rapid commercial agglutination test (Bactigen Strepto B) for detection of group B streptococci in gastric aspirates of neonates was evaluated. One hundred and sixty-one gastric samples were analyzed with conventional bacteriological techniques and with the commercial test after modification of the extraction technique. The sensitivity of the test relative to the culture technique was 90.4 %, the specificity 94.2 %, the positive predictive value 70.3 % and the negative predictive value 98.5 %. The commercial test could be performed in one hour and showed good sensitivity and specificity. If a test result was negative colonization could be excluded, obviating the need for empirical antibiotic therapy, whereas a positive result suggested colonization or neonatal infection with group B streptococci.     

Minitek urea disk test, a sensitive and cost-effective method to screen for Campylobacter pylori in gastric biopsies.

One hundred fifty-five biopsy specimens from the gastric mucosa of 81 patients undergoing routine endoscopy procedures were tested for the presence of Campylobacter pylori by three methods: Gram stain, culture, and modified Minitek, a rapid urea disk test (BBL Microbiology Systems, Cockeysville, Md.). Twenty-nine patients were infected with C. pylori. Sensitivities and specificities of detection were 100 and 94% with the Minitek test and 93 and 100% with Gram stain, respectively. Rapid testing by the urea disk is a simple, cost-effective, and accurate method for detecting the presence of C. pylori in gastric biopsy specimens.     

Comparison of serum trefoil factor 3 with the pepsinogen test for the screening of diffuse-type gastric cancer

Emerging data show that serum trefoil factor 3 (TFF3) alone and combined with the serum pepsinogen (PG) test can increase the diagnostic yield of gastric cancer. We aimed to evaluate the diagnostic value of serum TFF3 for the screening of gastric cancer in Korean patients, especially for the screening of the diffuse type of gastric cancer, and compared TFF3 to the serum PG test. We enrolled 25 healthy controls and 79 subjects with gastric cancer who underwent endoscopic resection or surgery from June 2006 to June 2015. Data about age, sex, histological type according to the Lauren classification, stage of gastric cancer, and status of H. pylori were collected. Serum levels of PG I and PG II were measured by the latex-enhanced turbidimetric immunoassay, and serum TFF3 levels were measured by enzyme-linked immunosorbent assay. The optimal cutoff value of serum TFF3 was ≥8.9 ng/mL to diagnose gastric cancer, with 73.4 % sensitivity and 92.0 % specificity, which were higher than those of the serum PG I/II ratio, with 69.6 % sensitivity and 68.0 % specificity. The optimal sensitivity and specificity of serum TFF3 for the diagnosis of diffuse-type gastric cancer were 68.0 and 92.0 %, respectively, which were lower than those for the diagnosis of intestinal-type gastric cancer (75.6 and 100 %, respectively). Serum TFF3 is a more stable and useful marker than the serum PG test for the screening of gastric cancer in Korean patients. Serum TFF3 showed good diagnostic power in detecting both intestinal- and diffuse-type gastric cancer although it showed decreased power in diffuse type.     

Shock-stress,gastric secretion and habituation in the chronic gastric fistula rat

Unrestrained rats exposed to shock-stress showed an abrupt reduction in both the volume and acidity of gastric secretions, followed by a rapid poststress recovery. The gastric response pattern did not distinguish between rats receiving avoidable or unavoidable shock. Marked habituation of the acid inhibition response occurred within 4 stress sessions.     

Rapid detection of gastric Campylobacter pylori colonization by a simple biochemical test.

A simple and rapid urease test to detect Campylobacter pylori infection was evaluated with bacterial culture as the "gold standard." The test was compared with the Gram stain and the conventional Christensen urease test. The culture method detected C. pylori in 29 of 49 gastric biopsy specimens. The rapid urease test showed 27 positive samples within 1 h at 55 degrees C (specificity, 100%; sensitivity, 93%) and 18 at room temperature (specificity, 100%; sensitivity, 62%). The Gram stain exhibited a sensitivity of 86% and a specificity of 91%. The conventional Christensen urease test detected C. pylori in only 4, 10, and 18 samples after 24, 48, and 72 h, respectively (sensitivities, 12, 36, and 60%, respectively; specificities, 95, 95, and 83%, respectively). We conclude that the rapid urease test is simple and highly specific for the detection of C. pylori and that it can be performed with small amounts of sample.     

Sympatho-adrenergic inhibition of vagally induced gastric motility and gastroduodenal HCO-3 secretion in the cat

Chloralosed cats were acutely vagotomized and their adrenal glands were ligated. The gastric lumen was perfused with isotonic NaCl and gastric motility was recorded as change in hydrostatic pressure within the perfusion circuit. Gastric secretions of H+ and HCO3- were calculated from continuous measurements of pH and pCO2 in the perfusate. Mucosal HCO3- secretion in the distal duodenum was titrated in situ by pH-stat equipment. The experiments were divided into three different groups dependent on the state of sympathetic splanchnic nervous supply: intact; cut on a preganglionic level; blocked with the adrenolytic agent guanethidine. Basal levels for gastric motility, gastric H+ and HCO3- secretions and duodenal HCO3- secretion were more or less similar in all groups. Gastric motility, gastric HCO3- and duodenal HCO3- secretory responses to bilateral vagal stimulation were significantly enhanced in splanchnicotomized or guanethidine-treated animals as compared to controls with intact sympathetic supply. However, no clear differences in gastric H+ secretory responses to vagal stimulation were demonstrated between animals with an intact or disrupted sympathetic innervation. These results suggest a sympatho-adrenergic inhibitory action on vagally induced mucosa-protective HCO3- secretion in the stomach and the duodenum. Furthermore, vagal stimulation in animals with intact splanchnic nerves induced a guanethidine-resistant delayed increase in duodenal HCO3- secretion. The nature of this response was not further analysed.     

Foam-stability test on gastric aspirate and the diagnosis of respiratory-distress syndrome.

Gastric aspirate, collected from 79 infants within 30 minutes of birth, was subjected to the foam-stability test. The lecithin/sphingomyelin ratio was determined in 27. The results were compared with the incidence of respiratory-distress syndrome as determined independently by different investigators. Of the 59 infants with a positive foam-stability test on gastric aspirate, three had transient respiratory distress, and one the respiratory-distress syndrome; 17 of 22 had lecithin/sphingomyelin ratios greater than 2.0. Of nine infants who had intermediate test results, three were normal, four had transient respiratory distress, and two had the respiratory-distress syndrome. In all the 11 infants with negative foam-stability tests the respiratory-distress syndrome developed. The three gastric aspirates tested in this group had lecithin/sphingomyelin ratios of less than 1.5. These data indicate that the foam-stability test on gastric aspirate is a reliable index of fetal lung maturity in infants whose amniotic fluid is not available.     

Effects of splanchnic nerve stimulation and of clonidine on gastric and duodenal HCO3- secretion in the anaesthetized cat

Experiments were performed on chloralose-anaesthetized cats with ligated adrenals. The vagal and splanchnic nerves were cut and arranged for peripheral electric stimulation. The gastric lumen was perfused with isotonic saline and gastric H+ and HCO3- secretions were calculated from pH/pCO2 measurements in the perfusate. Gastric motility was recorded as changes in hydrostatic pressure in the perfusion circuit. Mucosal HCO3- secretion into the duodenum was monitored in situ by pH-stat titration. Vagal stimulation (10 Hz for 10 min) increased gastric and duodenal HCO3- secretions, as well as gastric motor activity and H+ secretion. Splanchnic nerve stimulation (10 Hz for 10 min) did not affect gastric H+ and HCO3- secretions, but tended to decrease gastric motor tone and basal duodenal HCO3- secretion. Splanchnic nerve stimulation simultaneously with vagal stimulation inhibited gastric contractions and the rise in gastric H+ and duodenal HCO3- secretions observed in response to vagal stimulation alone, but had little effect on the rise in gastric HCO3- secretion. However, such vago-splanchnic stimulation in the presence of the alpha 2-adrenoceptor blocker yohimbine induced gastric contractions, H+ secretory and duodenal HCO3- secretory responses with magnitudes similar to those induced by vagal stimulation alone, whereas the gastric HCO3- secretory response was larger than by vagal stimulation alone. The alpha 2-adrenoceptor agonist clonidine (50 micrograms kg-1 h-1, i.v.) inhibited the gastric contractions and increases in gastric and duodenal HCO3- secretion in response to vagal stimulation, but did not influence vagal stimulation of gastric H+ secretion. The results suggest the existence of a peripheral sympatho-inhibitory action on gastric and duodenal HCO3- secretion involving alpha 2-adrenoceptors. Also splanchnic neural stimulatory effects on gastric and duodenal HCO3- secretion may exist.     

Diagnosis of Helicobacter pylori infection in children: comparison of a salivary immunoglobulin G antibody test with the [(13)C]urea breath test

The prevalence of Helicobacter pylori infection in a population-based sample of 477 children (mean age plus minus standard deviation, 5.8 plus minus 0.5 years) determined by the [(13)C]urea breath test ([(13)C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [(13)C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively.     

逆行胃电刺激对健康人水负荷、摄食量和胃排空的影响

目的观察逆行胃电刺激(RGES)对健康人胃容受性、摄食量和胃排空的影响。方法选择健康志愿者12人。沿胃大弯距幽门5 cm处放置一对黏膜电极,以胃动过速的频率9 cyc les/m in,波宽500 m s,强度5 mA的脉冲信号进行RGES。进行水负荷试验、摄食试验和核素闪烁扫描固体胃排空试验来评价RGES的效果。结果与对照阶段相比,RGES可引起摄水量减少13%(P<0.01),摄食减少16%(P<0.001),胃半排空时间延迟33%(P<0.05),120 m in食物存留率增加15%(P<0.05)。水负荷试验、摄食试验和胃排空试验应用的RGES参数没有引起显著症状。结论急性RGES可以显著减少摄水摄食,延缓胃排空,且不引起明显症状。     

Prediction of the risk for gastric cancer using candidate methylation markers in the non-neoplastic gastric mucosae

Aberrant DNA methylation is frequently found during gastric carcinogenesis. Recently, we identified potential methylation markers important for Helicobacter pylori-induced gastric carcinogenesis using an Illumina methylation chip assay. In this study, we evaluated the candidate genes as markers for gastric cancer (GC) in a large Korean population. DNA methylation of PTPN6, MOS, DCC, CRK, and VAV1 was evaluated in non-neoplastic gastric specimens using quantitative methylation-specific PCR in patients with GC (n = 207) and their age- and gender-matched controls (n = 207). Methylation levels in 125 GC samples were also compared. H. pylori infection status was categorized as negative, active, or past infection according to the results of endoscopy-based tests (CLOtest, histology, and culture), H. pylori serology, and serum pepsinogen test. In the controls, active H. pylori infection increased methylation levels in DCC, CRK, MOS, and VAV1 but decreased methylation levels in PTPN6 (all p < 0.05); the methylation levels in MOS remained increased in patients with past H. pylori infection compared to H. pylori-negative subjects (p < 0.001). Methylation levels in MOS in non-neoplastic gastric mucosae increased in the presence of GC, regardless of H. pylori infection status (p < 0.01). Methylation levels in all genes but DCC decreased significantly in GC specimens compared to neoplastic gastric mucosae (p < 0.01); however, methylation levels in GC tissues were not correlated with those in their background gastric mucosae. Hypomethylation of MOS in GC tissues was associated with tumour invasion, nodal metastasis, and undifferentiated histology (p < 0.05). To summarize, among the candidate genes, DNA methylation of MOS may reflect the duration of H. pylori exposure and may be a marker for the development of GC.     

UreC PCR based diagnosis of Helicobacter pylori infection and detection of cag A gene in gastric biopsies

Polymerase chain reaction assay using ureC gene specific primers for the detection of Helicobacter pylori in gastric biopsy specimens from 116 dyspeptic patients was compared with other routine invasive diagnostic methods (culture, rapid urease test [RUT] and histology). In parallel, gastric biospy specimens from 54 patients and their corresponding Helicobacter pylori isolates were subjected to PCR with cagA targeting primers using standard protocols. Helicobacter pylori were detected in 53%, 43%, 48% and 50% of patients by PCR, RUT, culture and histological examination respectively. Based on histology and culture positive and at least three test positive result, 44 (37%), 46 (39%) and 26 (22%), and 56 (48%), 52 (44%) and 8 (6%) patients were classified as Helicobacter pylori positive, negative and indeterminate respectively. The sensitivity and specificity of PCR assay was the highest-95% and 100% when compared with both culture and histology positive, and at least any three positive results respectively. The result of cagA positivity in 54 gastric biopsy specimens and their corresponding Helicobacter pylori isolates were identical; 18 of 20 (90%) duodenal ulcer patients and 23 of 28 (82%) patients with chronic gastritis and 2 (40%) of 5 patients with portal hypertension and one gastric biopsy specimens from gastric cancer patients were found to be cagA positive. PCR-based method to detect Helicobacter pylori and the virulence gene cag A directly from gastric biopsy specimens appears to be promising and can curtail the lengthy process of culture-based approaches. The procedure proved to be rapid and reliable and could be utilized for diagnostic purposes.     

Sensitivity of a novel stool antigen test for detection of Helicobacter pylori in adult outpatients before and after eradication therapy

We investigated whether a novel monoclonal stool antigen test for detection of Helicobacter pylori performs with the same accuracy as the (13)C-urea breath test (UBT) for adult outpatients in the setting of a private office. The two tests showed identical levels of sensitivity when used to identify H. pylori-infected patients before and after eradication therapy.     

Comparison of four stains and a urease test for rapid detection ofHelicobacter pylori in gastric biopsies

Gastric biopsies were obtained from 125 subjects to compare detection ofHelicobacter pylori by culture, a rapid urease test and histopathologic examination using haematoxylin-eosin, Gram, Giemsa, Warthin-Starry silver and acridine orange stains.Helicobacter pylori was isolated from 39 specimens. Acridine orange and Giemsa were the most sensitive stains, detecting 85 % and 79 % of positive specimens respectively. All stains showed high specificity (97–100 %). The sensitivity and specificity of the rapid urease test was 62 % and 100 % respectively. These stains or the rapid urease test may be useful for rapid detection ofHelicobacter pylori in gastric biopsies.     

胃癌及胃液中p53、ras基因突变与临床病理的关系

目的：探讨胃良性病变向恶性转化过程中p53、ras基因突变的规律，并分析胃癌无损伤基因检测的可行性。方法：应用PCR－SSCP及免疫组织化学方法对比研究。结果：异型增生p53基因突变率10％（3／30）、ras基因突变率10％（3／30）、ras基因突变率16．7％（5／30）（二者总突变率26．7％）；早期胃癌p53基因突变率35％（7／20）、ras基因突变率60％（12／20）（二者总突变率85％，其中2例重复突变）； 中晚期胃癌p53基因突变率60％（18／30）、ras基因突变率43．3％（13／30）（二者总突变率90％，其中4例重复突变）；胃息肉ras基因突变仅1／10。30例胃溃疡边缘正常黏膜均未发现p53、ras基因突变。p53基因突变的25例胃癌的胃液中其相应的突变率32％（8／25）。19例胃癌患者的胃液中9例有ras基因突变47．1％（9／19）。异型增生p53蛋白过度表达阳性率13．3％（4／30),p^21ras蛋白阳性率16．7％（5／30）。胃癌p53蛋白阳性率56％（28／50），p^21ras蛋白阳性率60％（30／50）。正常胃黏膜上皮、溃疡边缘正常黏膜及胃息肉均呈p53及ras蛋白阴性表达。结论：胃癌的发生发展与癌基因ras与抑癌基因p53的突变有关，且两种基因同时检测，可覆盖绝大多数胃癌病例，提高了本项技术的可靠性，提供了胃癌无损伤基因检测的可行性的实验证据。