Validación de una prueba de amonio en aliento para el diagnóstico de la infección por Helicobacter pylori en pacientes del Hospital Cayetano Heredia / Validation of an ammonia breath test for the diagnosis of Helicobacter pylori infection in patients with dyspepsia at Hospital Cayetano Heredia

Objetivo: Determinar la validez diagnóstica de una prueba de amonio en aire espirado para la infección por Helicobacter pylori en pacientes a los que se le realiza una endoscopía digestiva alta en el Hospital Cayetano Heredia. Material y métodos: De abril a diciembre del 2014 se evaluó a 155 pacientes con una prueba de amonio en aliento y la evaluación histopatológica de las biopsias de estómago (considerada como el patrón de oro) tomadas durante la endoscopía. Los datos fueron analizados en Microsoft Excel y STATA 14 para construir una curva ROC. Resultados: Los pacientes fueron predominantemente mujeres (71%), con una edad media de 53 años (18-84) y una prevalencia de Helicobacter pylori de 51,6%. Al comparar la prueba de amonio en aire espirado con la prueba histológica se obtiene una sensibilidad de 70%, especificidad de 36%, valor predictivo positivo de 53,8%, valor predictivo negativo de 36%, índice de probabilidad positivo de 1,15 e índice de probabilidad negativo de 0,75. De acuerdo a la curva ROC, no se encontró un punto de corte óptimo con adecuados valores de sensibilidad y especificidad y el área bajo la curva es de 0,5517. Conclusiones: Esta prueba de amonio en aliento (aire espirado) no presenta poder diagnóstico y no se recomienda como una herramienta para el diagnóstico de la infección por Helicobacter pylori.

Objetive: To determine the diagnostic validity of an ammonia breath test for Helicobacter pylori infection in patients who undergo an upper gastrointestinal endoscopy at Hospital Cayetano Heredia. Material and methods: From April to December 2014, 155 patients were evaluated with the ammonia breath test and compared with a histological evaluation of the gastric biopsies as the gold standard. Data were evaluated using Microsoft Excel and STATA 14 to build a ROC curve. Results: The patients were predominantly female (71%), with a median age of 53 years (18-84) and a Helicobacter pylori prevalence of 51.6%. The ammonia breath test, when compared to the gastric biopsy has a 70% sensitivity, 36% specificity, 53.8% positive predictive value, 36% negative predictive value, 1.15 positive likelihood ratio and 0.75 negative likelihood ratio. According to the ROC curve, there is not an optimal cut off value and the area under the curve was 0.5517. Conclusions: The ammonia breath test evaluated on this study does not have diagnostic accuracy and is not recommended as a diagnostic tool for Helicobacter pylori infection.

Activation of NF-κB and AP-1 Mediates Hyperproliferation by Inducing β-Catenin and c-Myc in Helicobacter pylori-Infected Gastric Epithelial Cells

PURPOSE: In the gastric mucosa of Helicobacter pylori (H. pylori)-infected patients with gastritis or adenocarcinoma, proliferation of gastric epithelial cells is increased. Hyperproliferation is related to induction of oncogenes, such as β-catenin and c-myc. Even though transcription factors NF-κB and AP-1 are activated in H. pylori-infected cells, whether NF-κB or AP-1 regulates the expression of β-catenein or c-myc in H. pylori-infected cells has not been clarified. The present study was undertaken to investigate whether H. pylori-induced activation of NF-κB and AP-1 mediates the expression of oncogenes and hyperproliferation of gastric epithelial cells. MATERIALS AND METHODS: Gastric epithelial AGS cells were transiently transfected with mutant genes for IκBα (MAD3) and c-Jun (TAM67) or treated with a specific NF-κB inhibitor caffeic acid phenethyl ester (CAPE) or a selective AP-1 inhibitor SR-11302 to suppress activation of NF-κB or AP-1, respecively. As reference cells, the control vector pcDNA was transfected to the cells. Wild-type cells or transfected cells were cultured with or without H. pylori. RESULTS: H. pylori induced activation of NF-κB and AP-1, cell proliferation, and expression of oncogenes (β-catenein, c-myc) in AGS cells, which was inhibited by transfection of MAD3 and TAM67. Wild-type cells and the cells transfected with pcDNA showed similar activities of NF-κB and AP-1, proliferation, and oncogene expression regardless of treatment with H. pylori. Both CAPE and SR-11302 inhibited cell proliferation and expression of oncogenes in H. pylori-infected cells. CONCLUSION: H. pylori-induced activation of NF-κB and AP-1 regulates transcription of oncogenes and mediates hyperproliferation in gastric epithelial cells.

Dyspeptic symptoms in patients with type 1 diabetes: endoscopic findings, Helicobacter pylori infection, and associations with metabolic control, mood disorders and nutritional factors

Objectives To evaluate, in a group of patients with long-standing type 1 diabetes (DM1), an association of dyspepsia symptoms with: changes in the gastroduodenal mucosa, infection by Helicobacter pylori, glycemic control, and psychological and nutritional factors. Subjects and methods A total of 32 patient with DM1 were studied (age: 38 ± 9 years; females: 25; diabetes duration: 22 ± 5 years). All patients answered a standardized questionnaire for the evaluation of gastrointestinal symptoms and underwent upper gastrointestinal endoscopy, with gastric biopsies for the evaluation of Helicobacter pylori infection. The presence of anxiety and depression was evaluated by the HAD scale. Nutritional parameters were BMI, arm and waist circumference, skinfold measurement, and body fat percentage. Results Upper endoscopy detected lesions in the gastric mucosa in 34.4% of the patients, with similar frequency in those with (n = 21) and without dyspepsia (n = 11). The patients with dyspepsia complaints showed greater frequency of depression (60% vs. 0%; p = 0.001), higher values for HbA1c (9.6 ± 1.7 vs. 8.2 ± 1.3%; p = 0.01) and lower values for BMI (24.3 ± 4.1 vs. 27.2 ± 2.6 kg/m2; p = 0.02), body fat percentage (26.6 ± 6.2 vs. 30.8 ± 7.7%; p = 0.04), and waist circumference (78.7 ± 8 vs. 85.8 ± 8.1 cm; p = 0.02). No association was found between the symptoms and the presence of Helicobacter pylori. Conclusions Dyspepsia symptoms in patients with long-standing DM1 were associated with glycemic control and depression, and they seem to negatively influence the nutritional status of these patients. .

Diphenyleneiodonium Inhibits Apoptotic Cell Death of Gastric Epithelial Cells Infected with Helicobacter pylori in a Korean Isolate

NADPH oxidase produces a large amount of reactive oxygen species (ROS) in Helicobacter pylori (H. pylori)-induced gastric epithelial cells. Even though ROS mediate apoptotic cell death, direct involvement of NADPH oxidase on H. pylori-induced apoptosis remains unclear. Besides, H. pylori isolates show a high degree of genetic variability. The predominant genotype of H. pylori in Korea has been reported as cagA+, vacA s1b, m2, iceA genotype. Present study aims to investigate whether NADPH oxidase-generated ROS mediate apoptosis in human gastric epithelial AGS cells infected with H. pylori in a Korean isolate. AGS cells were pretreated with or without an NADPH oxidase inhibitor diphenyleneiodonium (DPI) and cultured in the presence of H. pylori at a bacterium/cell ratio of 300:1. Cell viability, hydrogen peroxide level, DNA fragmentation, and protein levels of p53, Bcl-2, and Bax were determined. Results showed that H. pylori inhibited cell viability with the density of H. pylori added to the cells. Inhibition of NADPH oxidase by DPI suppressed H. pylori-induced cell death, increased hydrogen peroxide, DNA fragmentation, and the ratio of Bax/Bcl-2, and p53 induction in AGS cells dose-dependently. The results suggest that targeting NADPH oxidase may prevent the development of gastric inflammation associated with H. pylori infection by suppressing abnormal apoptotic cell death of gastric epithelial cells.

Lesiones gástricas en pacientes infectados con Helicobacter pylori: expresión de RAGE (receptor de productos de glicosilización avanzada) y otros inmunomarcadores / Expression of RAGE in Helicobacter pylori infested gastric biopsies

Background: Inflammation is a common phenomenon present in gastric mucosa of patients infected with H. pylori. Activation of the RAGE/multiligand axis is thought to be a relevant factor in cancer-mediated inflammation. RAGE is a membrane receptor, belonging to the immunoglobulin family, and the over-expression of RAGE has been associated with increased invasiveness and metastasis generation in different types of cancer, including gastric cancer. Furthermore recent experiences show that the use of its soluble form (sRAGE) or silencing of the gene coding for this receptor could provide therapeutic benefits in cancer. Aim: To evaluate the immunohistochemical expression of RAGE, MUC-1, β-Catenin free and phosphorylated, Cyclin-D1 and GSK3 in gastric biopsy specimens infected with H. pylori. Material and Methods: Immunohistochemical analysis was carried out in gastric biopsies from 138 patients: 55 with inflammatory injury (no atrophic gastritis), 42 with pre-cancerous conditions (atrophy or intestinal metaplasia) and 41 with dysplastic lesions or in situ adenocarcinoma. Results: There was a high rate of positive RAGE expression in the three groups of biopsies. Biopsies with dysplasia or in situ carcinoma had a significantly higher percentage of RAGE expression than the other groups of biopsies. Conclusions: The increased RAGE expression reported in both dysplasia and incipient cancer support the role of the multiligand/RAGE axis in gastric carcinogenesis.

An Inverse Relationship between the Expression of the Gastric Tumor Suppressor RUNX3 and Infection with Helicobacter pylori in Gastric Epithelial Dysplasia

BACKGROUND/AIMS: This study was performed to determine the association between RUNX3 expression and Helicobacter pylori infection in premalignant gastric lesions. METHODS: We examined 107 patients with gastric epithelial dysplasia who had undergone endoscopic mucosal resection or submucosal dissection. All tissue samples were evaluated by RUNX3 staining and subclassified by immunophenotype. H. pylori infection in dysplastic lesions and the normal surrounding tissue was examined by silver staining, and cagA status was assessed by polymerase chain reaction. RESULTS: The loss of RUNX3 expression was observed in 62 cases (57.9%), and an association with H. pylori infection was found in 54 cases (50.5%). The infection rate with the cagA-positive H. pylori strain was 63.0%. In RUNX3-negative lesions, the rate of H. pylori infection (p=0.03) and the frequency of category 4 lesions (according to the revised Vienna classification) were high (p=0.02). In addition, the gastric mucin phenotype was predominant. In RUNX3-negative category 4 lesions, the rate of cagA-positive H. pylori infection rate was high but not significantly increased (p=0.08). CONCLUSIONS: Infection with H. pylori is associated with inactivation of RUNX3 in early gastric carcinogenesis. This mechanism was prominent in gastric cancer with a gastric mucin phenotype.

Gastric Autoantigenic Proteins in Helicobacter Pylori Infection

PURPOSE: This study tried to identify novel gastric autoimmune antigens that might be involved in aggravating the atrophic gastritis among patients with Helicobacter pylori infection using two-dimensional immunoblotting analysis. MATERIALS AND METHODS: Proteins from gastric mucosal antrectomy specimens and AGS cells (gastric adenocarcinoma cell lines derived from a Caucasian patient who had received no prior therapy) were 2-dimensionally immunoblotted separately with a pool of 300 sera from H. pylroi-infected patients at Gyeongsang National University Hospital. RESULTS: Thirty-eight autoantigenic proteins including alcohol dehydrogenase [NADP+], alpha enolase, gastrokine-1, gastric triacylglycerol lipase, heat shock 70 kDa protein 1, and peroxiredoxin-2 were identified in the gastric mucosal tissue. Fourteen autoantigenic proteins including programmed cell death 6-interacting protein, serum albumin and T-complex protein 1 subunit gamma were identified in the AGS cells. Albumin, alpha-enolase, annexin A3, cytoplasmic actin 1, heat shock cognate 71 kDa protein and leukocyte elastase inhibitor were commonly observed autoantigenic proteins in both gastric mucosal tissue and AGS cells. Alpha-enolase, glutathione S-transferase P, heat shock cognate 71 kDa protein, heat shock 70 kDa protein 1, human mitochondrial adenosine triphosphate synthase (ATP) subunit beta, mitochondrial 60 kDa heat shock protein, peroxiredoxin-2, 78 kDa glucose-regulated protein precursor, tyrosine-protein phosphatase non-receptor type 11 and Tryptophan-Aspartic acid (WD) repeat-containing protein 1 showed 60% or higher amino acid positivity. CONCLUSION: These newly identified gastric autoimmune antigens might be useful in the control and prevention of gastroduodenal disorders, and might be valuable in breaking the vicious circle that exists in gastroduodenal disorders if their pathophysiological roles could be understood in the progress of chronic atrophic gastritis, gastroduodenal ulcers, intestinal metaplasia, and gastric carcinogenesis.

Vitamin B12 deficiency & levels of metabolites in an apparently normal urban south Indian elderly population.

Background & objectives: There is no published literature on the extent of vitamin B12 deficiency in elderly Indians as determined by plasma vitamin B12 levels and methylmalonic acid (MMA) levels. Vitamin B12 deficiency is expected to be higher in elderly Indians due to vegetarianism, varied socio-economic strata and high prevalence of Helicobacter pylori infection. We therefore, studied the dietary habits of south Indian urban elderly population and measured vitamin B12, MMA red cell folate and homocysteine (Hcy) levels. Methods: Healthy elderly urban subjects (175, >60 yr) were recruited. Detailed history, physical examination and neurological assessment were carried out. Food Frequency Questionnaire (FFQ) for dietary analysis for daily intake of calories, vitamin B12, folate and detailed psychological assessment for cognitive functions was carried out. Blood samples were analyzed for routine haematology and biochemistry, vitamin B12, red cell folate, MMA and Hcy. Results: The mean age of the study population was 66.3 yr. Median values for daily dietary intake of vitamin B12 and folate were 2.4 and 349.2 μg/day respectively. Sixty two (35%) participants consumed multivitamin supplements. Plasma vitamin B12 level and the dietary intake of vitamin B12 was significantly correlated (P=0.157). Plasma vitamin B12 and Hcy were inversely correlated (P= -0.509). Red cell folate was inversely correlated with Hcy (P= -0.550). Significant negative correlation was observed between plasma vitamin B12 and MMA in the entire study population (P= -0.220). Subjects consuming vitamin supplements (n=62) had significantly higher plasma vitamin B12 levels, lower MMA levels and lower Hcy levels. There was no significant correlation between plasma vitamin B12, MMA, Hcy and red cell folate and any of the 10 cognitive tests including Hindi Mental Status Examination (HMSE). Interpretation & conclusions: Our study is indicative of higher vitamin B12 (2.4 μg/day) intakes in urban south Indian population. Thirty five per cent of the study population consumed multivitamin supplements and therefore, low plasma vitamin B12 levels were seen only in 16 per cent of the study subjects. However, MMA was elevated in 55 per cent and Hcy in 13 per cent of the subjects.

Expression of TERT in precancerous gastric lesions compared to gastric cancer

The objective of this study was to determine the levels of TERT mRNA and TERT protein expression in stomach precancerous lesions such as intestinal metaplasia (IM) and gastric ulcer (GU) and compare them to gastric cancer (GC). Real-time PCR was performed to detect TERT mRNA expression levels in 35 biopsies of IM, 30 of GU, and 22 of GC and their respective normal mucosas. TERT protein was detected by immunohistochemistry in 68 samples, 34 of IM, 23 of GU, and 11 of GC. Increased TERT mRNA expression levels were observed in a significant number of cases, i.e., 46 percent of IM, 50 percent of GU, and 79 percent of GC. The relative mean level of TERT mRNA after normalization with the β-actin reference gene and comparison with the respective adjacent normal mucosa was slightly increased in the IM and GU groups, 2.008 ± 2.605 and 2.730 ± 4.120, respectively, but high TERT mRNA expression was observed in the GC group (17.271 ± 33.852). However, there were no statistically significant differences between the three groups. TERT protein-positive immunostaining was observed in 38 percent of IM, 39 percent of GU, and 55 percent of GC. No association of TERT mRNA and protein expression with Helicobacter pylori infection or other clinicopathological variables was demonstrable, except for the incomplete type vs the complete type of IM. This study confirms previous data of the high expression of both TERT mRNA and protein in gastric cancer and also demonstrates this type of changed expression in IM and GU, thus suggesting that TERT expression may be deregulated in precursor lesions that participate in the early stages of gastric carcinogenesis.

Expression of Peroxisome Proliferator-activated Receptor (PPAR)gamma in Helicobacter pylori-infected Gastric Epithelium / 대한소화기학회지

BACKGROUND/AIMS: Peroxisome proliferator-activated receptorgamma (PPARgamma), a nuclear transcription factor, plays a critical role in the regulation of gene expression associated with inflammation and cancer. PPARgamma is expressed in human gastric cancer as well as in colon cancer. Activation of PPARgamma by ligand produces pro-apoptotic effect and ameliorate growing of cancer cells. Helicobacter pylori (H. pylori) is a main etiologic agent for gastric inflammation, and raises cell turnover in gastric epithelium. Longstanding infection with this organism is related with the development of non-cardiac gastric cancer. The aim of this study was to investigate the effect of H. pylori on the expression of PPARgamma protein and mRNA in chronic gastritis. METHODS: Gastric biopsy samples were taken from H. pylori infected (n=18) and non-infected (n=21) patients during endoscopic examination. PPARgamma expressions were assessed by real time polymerase chain reaction and immunohistochemistry. RESULTS: PPARgamma was localized to the nuclei of the foveolar epithelial cells in both infected and non-infected mucosa. PPARgamma protein expression was higher in H. pylori infected patients than in non-infected patients (3.8+/-0.4 vs. 2.6+/-1.0, H. pylori infected and non-infected, respectively; p<0.05). However, PPARgamma mRNA levels were not significantly different between the two groups (24+/-18 vs. 29+/-25, H. pylori infected and noninfected, respectively). CONCLUSIONS: PPARgamma expression is increased in the gastric mucosa of H. pylori infected chronic gastritis, which suggests a certain role of PPARgamma in the mucosal inflammatory reaction to H. pylori infection.

Expression of Peroxisome Proliferator-activated Receptor (PPAR)gamma in Helicobacter pylori-infected Gastric Epithelium / 대한소화기학회지

No abstract availble.

Ureases display biological effects independent of enzymatic activity: Is there a connection to diseases caused by urease-producing bacteria?

Ureases are enzymes from plants, fungi and bacteria that catalyze the hydrolysis of urea to form ammonia and carbon dioxide. While fungal and plant ureases are homo-oligomers of 90-kDa subunits, bacterial ureases are multimers of two or three subunit complexes. We showed that some isoforms of jack bean urease, canatoxin and the classical urease, bind to glycoconjugates and induce platelet aggregation. Canatoxin also promotes release of histamine from mast cells, insulin from pancreatic cells and neurotransmitters from brain synaptosomes. In vivo it induces rat paw edema and neutrophil chemotaxis. These effects are independent of ureolytic activity and require activation of eicosanoid metabolism and calcium channels. Helicobacter pylori, a Gram-negative bacterium that colonizes the human stomach mucosa, causes gastric ulcers and cancer by a mechanism that is not understood. H. pylori produces factors that damage gastric epithelial cells, such as the vacuolating cytotoxin VacA, the cytotoxin-associated protein CagA, and a urease (up to 10 percent of bacterial protein) that neutralizes the acidic medium permitting its survival in the stomach. H. pylori whole cells or extracts of its water-soluble proteins promote inflammation, activate neutrophils and induce the release of cytokines. In this paper we review data from the literature suggesting that H. pylori urease displays many of the biological activities observed for jack bean ureases and show that bacterial ureases have a secretagogue effect modulated by eicosanoid metabolites through lipoxygenase pathways. These findings could be relevant to the elucidation of the role of urease in the pathogenesis of the gastrointestinal disease caused by H. pylori.

Ghrelin; Influences on Helicobacter pylori-associated Gastric Diseases / 대한소화기학회지

Recently, gastric Helicobacter pylori (H. pylori) colonization has been shown to affect the expression of leptin and ghrelin, hormones that control appetite and satiety. Gastric leptin, produced by chief and parietal cells and released in response to meals, may play a role in weight gain after eradication of H. pylori infection, whereas ghrelin, produced by X/A-like enteroendocrine cells in oxyntic gland, is released during fasting, and suppressed by feeding and leptin. Whether either that H. pylori genes represent microbial contributions to the complement of thrifty genes of humans, or that H. pylori disappearance plays a role in adiposity remains to be determined. Simply, ghrelin-leptin might tango in body weight regulation, gastric inflammation, and gastric motility. In the current review about the possible role of ghrelin in gastric inflammation, we found that high serum albumin condition decreased ghrelin expression, whereas serum albumin deprivation significantly increased ghrelin expression, however, of which regulation was abolished after H. pylori infection. Ghrelin significantly attenuated the inflammatory stimuli imposed after H. pylori, shown with inactivation of phospho-extracellular signal-regulated kinase (p-ERK) and nuclear factor-KappaB (NF-KappaB)-DNA binding activities. Conclusively, besides orexigenic and weight gaining actions of gastric hormone, ghrelin, it likely endows the stomach the protective effect from exogenous damages.

Usefulness of NCI-N87 Cell Lines in Helicobacter pylori Infected Gastric Mucosa Model / 대한소화기학회지

BACKGROUND/AIMS: The unavailability of human gastric cell lines representative of the normal gastric epithelial function such as polarized monolayer restricts the application of cell culture system in approaching the field of Helicobacter pylori (H. pylori) infected gastric mucosa models. The present investigation aimed at assessing the usefulness of NCI-N87 cell line as an adequate cellular model to study the pathophysiology of human H. pylori infection. METHODS: For the identification of epithelial phenotypes at low magnification, cells were observed on a phase-contrast microscope and confocal microscope. Transepithelial resistance (TER) was measured on NCI-N87 cells seeded on Transwell(R) to identify monolayer polarity two or three times a week after confluency. The IL-8 level was determined by ELISA at 24 hours after the administration of HP60190 and IL-1alpha on NCI-N87 cells. IL-8 level was compared in both upper and lower well with the control. RESULTS: A monolayer phenotype was observed in NCI-N87 cell lines by using confocal microscope. TER was measured as 400-500 (omega x cm2) at two or three weeks after cell culture. In NCI-N87 cell lines, IL-8 level was significantly increased after 24 hour compared to control, and was prominent in the lower well. CONCLUSIONS: These results suggest that NCI-N87 cell line may be useful in H. pylori infected gastric mucosa model.

Glutathione Levels in Helicobacter pylori-infected Gastric Mucosa / 대한소화기학회지

BACKGROUND/AIMS: Oxidative stress may contribute to gastric epithelial damage and mutagenesis caused by Helicobacter pylori (H. pylori). H. pylori induces recruitment and activation of inflammatory cells, which produces reactive oxygen species. H. pylori extract directly induces the synthesis of reactive oxygen species in gastric epithelial cells and causes DNA damage. The aim of this study was to investigate the association between the levels of glutathione (GSH) and H. pylori density, histological findings, endoscopic findings, clinical variables, and virulence factors. METHODS: Gastric biopsy specimens were obtained from 73 consecutive patients. The 5,5'-dithiobis-(2-nitrobenzoic acid) reaction was used to determine GSH levels. RESULTS: The infection rate of H. pylori was 68.5%. The GSH level was not related to age, sex, alcohol intake, and endoscopic findings. The GSH level was lower in patients infected with H. pylori. GSH levels were not correlated significantly with the grades of neutrophil, intestinal metaplasia, and atrophy. However, the GSH levels were significantly correlated with H. pylori density (r=-0.296, p=0.01) and monocyte grade (r=-0.257, p=0.02). The GSH levels were not related to CagA, VacA, and UreA. CONCLUSIONS: This study suggests that H. pylori causes oxidative stresses which deplete GSH in gastric mucosa of patients infected with H. pylori.

Glutathione Levels in Helicobacter pylori-infected Gastric Mucosa / 대한소화기학회지

BACKGROUND/AIMS: Oxidative stress may contribute to gastric epithelial damage and mutagenesis caused by Helicobacter pylori (H. pylori). H. pylori induces recruitment and activation of inflammatory cells, which produces reactive oxygen species. H. pylori extract directly induces the synthesis of reactive oxygen species in gastric epithelial cells and causes DNA damage. The aim of this study was to investigate the association between the levels of glutathione (GSH) and H. pylori density, histological findings, endoscopic findings, clinical variables, and virulence factors. METHODS: Gastric biopsy specimens were obtained from 73 consecutive patients. The 5,5'-dithiobis-(2-nitrobenzoic acid) reaction was used to determine GSH levels. RESULTS: The infection rate of H. pylori was 68.5%. The GSH level was not related to age, sex, alcohol intake, and endoscopic findings. The GSH level was lower in patients infected with H. pylori. GSH levels were not correlated significantly with the grades of neutrophil, intestinal metaplasia, and atrophy. However, the GSH levels were significantly correlated with H. pylori density (r=-0.296, p=0.01) and monocyte grade (r=-0.257, p=0.02). The GSH levels were not related to CagA, VacA, and UreA. CONCLUSIONS: This study suggests that H. pylori causes oxidative stresses which deplete GSH in gastric mucosa of patients infected with H. pylori.

Oxidative stress in gastric mucosa in Helicobacter pylori infection.

BACKGROUND: Infection with Helicobacter pylori is believed to be associated with generation of reactive oxygen molecules which leads to oxidative stress in the gastric mucosa; but the relation between oxidative stress and gastrointestinal mucosal damage has not been documented. AIM: To look for evidence of oxidative stress and lipid peroxidation in the gastric mucosa in H. pylori-associated peptic ulcer. METHODS: 34 duodenal ulcer (DU) patients with H. pylori infection, 14 DU patients without H. pylori infection and 10 healthy subjects without H. pylori infection were studied. H. pylori infection was diagnosed by histology and rapid urease test on endoscopic biopsies from the gastric body and antrum. Reduced glutathione (GSH) and malondialdehyde (MDA) content were measured in biopsies taken from the gastric antrum. Statistical analysis was done using Student's t test. RESULTS: Tissue levels of GSH were significantly lower (91.7 [35.4] nmole/100 mg versus 147.3 [41.2] nmole/100 mg; p < 0.001) and MDA higher (163.0 [83.4] nmole/100 mg versus 109.2 [51.3] nmole/100 mg; p < 0.01) in patients with DU associated with H. pylori infection as compared to those without H. pylori infection. GSH levels were significantly lower and MDA levels higher in DU patients with or without H. pylori infection as compared to control subjects. Serum MDA levels in DU patients with H. pylori infection were also significantly higher than in patients without H. pylori infection. CONCLUSION: Depletion of gastric mucosal glutathione in H. pylori-infected DU patients may be due to failure of the antioxidant defense system. Failure of the glutathione-dependent defense system results in accumulation of free radicals which can initiate membrane damage by lipid peroxidation.

Effect of Helicobacter pylori infection on antral gastrin and somatostatin cells and on serum gastrin concentrations

OBJECTIVES: Helicobacter pylori infection induces selective reduction of the number of antral D-cells and results in abnormal regulation of serum gastrin secretion. The purpose of this study was to investigate the relationship between H. pylori infection and the numbers of G-cells and D-cells. METHODS: The numbers of antral G-cells and D-cells, the ratio of G-cells to D-cells and fasting serum gastrin concentrations were compared between 37 patients with (29 with duodenal ulcers and 8 with gastric ulcers) and 33 without H. pylori infection (22 with duodenal ulcers and 11 with gastric ulcers). Serum gastrin concentrations were measured using the radioimmunoassay technique. Antral mucosal biopsy specimens were examined using immunohistochemical staining with antibodies specific for gastrin and somatostatin and the numbers of G-cells and D-cells per gastric gland were counted. RESULTS: Fasting serum gastrin concentrations were significantly higher in patients with H. pylori infection compared to patients without infection (80.3 +/- 23.5 vs 47.6 +/- 14.1 pg/ml, p 0.5). The number of D-cells was significantly lower in patients with H. pylori infection than in uninfected patients in both duodenal and gastric ulcer patients (1.3 +/- 0.4 vs 2.5 +/- 1.6, respectively, p < 0.001). The ratio of G-cells to D-cells was also significantly higher in infected patients compared with uninfected patients for both gastric and duodenal ulcers (5.7 +/- 2.7 vs 3.5 +/- 1.9, respectively, p < 0.001). CONCLUSIONS: These results strongly suggest that Helicobacter pylori infection induces reduction of the number of antral D-cells. The resulting relative hypofunction of the inhibitory action of D-cells against G-cells may be responsible for increased serum gastrin secretion.

Crecimiento y evolución del Helicobacter pylori / Growth and evolution of Helicobacter pylori

El género Helicobacter tiene una historia relativamente reciente. Su protagonismo data del año 1982, fecha en la que el Helicobacter Pylori se aisló por primera vez de paciente humanos. Esta bacteria, inicialmente, se incluyó en el género Campylobacter y se la denominó Campylobacter Pylori o Piloridis. Posteriormente en el año 1989, se separo de este género y se creó uno nuevo el género Helycobacter, al que actualmente pertenecen varias especies. Los expertos en microbiología le asignaron este término por su forma de hélice in vivo y sus caracteres de bacteria in vitro, ya que encontraron que la denominación Campylobacter era errónea en vista del contenido de ácidos grasos de su pared y por el análisis del ADN se dieron cuenta que la bacteria no pertenecía a los Campylobacter.