Top PDF Cell-cycle inhibition by Helicobacter pylori L-asparaginase.

Cell-cycle inhibition by Helicobacter pylori L-asparaginase.

Cell-cycle inhibition by Helicobacter pylori L-asparaginase.

an intensity profile matching the profile of cell-cycle inhibiting activity (Fig. 1C and Supplementary Fig. S1). Analysis of these bands by LC-MS and MS-MS revealed multiple proteins (Table 1), with their N-terminal sequences confirmed in several cases (data not shown). With the exception of c-glutamyltranspeptidase (GGT) and L-asparaginase, detected in the bands corresponding to approximately 15 and 121 kDa, respectively, no other homo- logues of the other proteins found have been reported to interfere with the cell cycle. GGT (locus tags HP1118 in the H. pylori 26695 genome) is responsible of cell-cycle inhibition in T-cells [24] and in AGS cells [25]. The expected molecular mass of this protein in native conditions is 60 kDa, but a fragment with a molecular mass of 13.3 kDa and corresponding to residues 448–564 was previously isolated by 2D electrophoresis and peptide fingerprint- ing in the H. pylori secretome [26]. Our MS data are compatible with the predicted tryptic peptides derived from this fragment (49.6% coverage) and indicate that the latter is likely to exist as an independent unit whose significance is thus far unknown. L- asparaginase (locus tag HP0723, ‘‘probable asparaginase by sequence similarity’’), belongs to an important family of related amidohydrolases that catalyse the deamidation of L-asparagine (Asn) [27]. The molecular mass of a single subunit is 37 kDa, but, being in the absence of denaturation, the enzyme was correctly detected in its tetrameric functional form (theoretical MW 144 kDa). Cells lacking a functional asparagine synthetase and exposed to L-asparaginase undergo cell-cycle arrest in G1 and, in some cases, such as Acute Lymphatic Leukemia (ALL), die by apoptosis [28]. These features prompted us to investigate whether GGT and L-asparaginase were involved in this process.
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Engineering of Helicobacter pylori L-asparaginase: characterization of two functionally distinct groups of mutants.

Engineering of Helicobacter pylori L-asparaginase: characterization of two functionally distinct groups of mutants.

Previous work on EcAII [16] has shown that GLNase activity is essential for cell cytotoxicity only when ASNS is expressed. In the model proposed by the Authors, L-GLN, one of the sub- strates of ASNS, is removed by the secondary GLNase activity of ASNase, thus contributing to enhance cytotoxicity. HL-60 cells are known to express ASNS [34], thus explaining the effects we observed at comparable units of ASNase. In the absence of GLNase activity (M121C/ T169M mutant), the effect on cell viability was similar to the one exerted by the T16D mutant, devoid of any activity. In the presence of intermediate GLNase units (wild-type), cytotoxicity became relevant. It is interesting to note that, doubling GLNase units (Q63E mutant) com- pared to the wild-type, the further gain in cytotoxicity is only about 10% and this, because of the subsaturating L-GLN concentrations in which the experiments were performed (2 mM, as initially added to the culture medium), is probably related not to the lower affinity of Q63E for L-GLN with respect to the wild-type, but to its roughly halved GLNase efficiency (k cat /S 0.5 vs
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In vitro antagonistic activity of Lactobacillus casei against Helicobacter pylori

In vitro antagonistic activity of Lactobacillus casei against Helicobacter pylori

market. Different lactobacilli could be used for inhibition of H. pylori colonization through different mechanisms. Oral intake of L. johnsonii La1 was reported in many clini- cal studies and confirmed by different bacteriological and pathological examinations to attenuate H. pylori by reduc- ing pro-inflammatory chemotactic signals, which are responsible for the recruitment of lymphocytes and neutro- phils in the lamina propria (Gotteland and Cruchet, 2003; Sgouras et al., 2005). Moreover, L. gasseri OLL2716 was proved to follow the mechanism of induction. The coccoid conversion of H. pylori by lactic acid secretion (Canducci et al., 2002) and L. acidophilus exert an antagonistic effect against H. pylori through the production of a heat stable protein that exerts the antimicrobial effect other than lactic acid, which is only sensitive to enzymatic treatments (Coconnier et al., 1998). In this study, L. casei produces a large amount of lactic acid that has been confirmed by the reduction in pH; lactate has been implicated as an inhibi- tory factor for H. pylori due to its antimicrobial effect re- sulting from lowering the pH and its ability to inhibit the urease enzyme (Midolo et al., 1995; Sgouras et al., 2004). Although some studies have reported that only viable cells of L. casei can inhibit H. pylori growth (Coconnier et al., 1998; Sgouras et al., 2004), other studies have investigated the importance of other factors such as pH and lactic acid production (Bhatia et al., 1989; Lorca et al., 2001). In our study, we adjusted the pH to 5.5 as it is known that the low pH environment was found to increase the activity of lactobacilli (Boyanova et al., 2009), while lactic acid pro- duction was found to inhibit urease enzyme secretion from H. pylori, which plays a role in counteracting the stomach acidity (Servin, 2004; Sgouras et al., 2004). Recently, a striking mechanism for L. casei has been reported, which gleaned its power in making irreversible inhibition of the swimming motility of H. pylori through changes in cell morphology, replacing the helical cells by “c”-shaped and coccoid cells, and losing of FlaA and FlaB flagellins (Le Moal et al., 2013). Another in vivo study showed that L. casei could prevent enteric infections and stimulate secre- tory IgA in malnourished animals by inducing the in- creased systemic immune response, and it is also proved in the same study that L. casei was the most effective among other lactobacilli (Perdigon et al., 1995). Proteomic analy- sis of bacteria usually revealed plenty of information about its proteins and their role in the cell (Enany et al., 2012;
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Anti-Helicobacter pylori activity and oxidative burst inhibition by the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Anti-Helicobacter pylori activity and oxidative burst inhibition by the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Treatment of H. pylori infection consists of 1-2 weeks of 1 or 2 effective antibiotics, including amoxicillin, tetracycline, metronidazole, or clarithromycin, plus ranitidine bismuth citrate, bismuth subsalicylate, or a proton pump inhibitor (Howden & Hunt, 1998; Duynhoven & Jonge, 2001; Park et al., 2006). However, this triple therapy is not always successful in eradicating the infection, and the acquisition of antibiotic resistance by H. pylori could reduce treatment efficacy and present a serious problem (Bonacorsi et al., 2009). As eradication therapies can be ineffective and undesirable side effects may occur, the search for new drugs for use in alternative therapies is very important (Stege et al., 2006; Zaidi et al., 2009).
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Helicobacter pylori virulence genes detected by string PCR in children from an urban community in northeastern Brazil

Helicobacter pylori virulence genes detected by string PCR in children from an urban community in northeastern Brazil

H elicobacter pylori infection significantly increases the risk of development of peptic ulcer disease, distal gastric carcinoma, and gastric lymphoma (1). Infection of the general population with virulent strains, especially those carrying the cagA gene and vacAs1 genotype, is a predictor of increased risk for development of severe H. pylori-associated diseases. However, the majority of the methods used for genotyping H. pylori strains require an in- vasive procedure, endoscopy, for tissue sample collection and are not indicated in epidemiological studies evaluating asymptomatic individuals, especially children. The string test, a minimally inva- sive nonendoscopic procedure, seems to be an accurate method to obtain gastric specimens in order to investigate H. pylori virulence genes. It has been demonstrated that the genotypes of H. pylori strains in DNA from the gastric juice or tissue samples are identi- cal (2).
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Infecção pelo helicobacter pylori e sua correlação com os sintomas dispépticos e evolução da gravidez .

Infecção pelo helicobacter pylori e sua correlação com os sintomas dispépticos e evolução da gravidez .

Exame sorológico - A determinação semiquantitativa de anticorpos da classe IgG anti – Helicobacter pylori foi realizada empregando-se “kit” ELISA indireto, não competitivo, de proce- dência comercial (Varelisa H.pylori IgG Antibodies, Pharmacia & Upjohn Diagnostics GmbH & Co., Germany), de acordo com as instruções dos fabricantes. A sensibilidade deste teste é de 96% comparada a biópsias endoscópicas positivas, e sua especificidade é de 92% comparada a biópsias negativas, segundo o fabricante. Para sua realização, 100 ml das amostras e dos soros controles diluídos a 1:101 foram adicionados às placas plásticas de micro- circulação, sensibilizadas com antígenos do H. pylori acrescidos de antígeno recombinante de 120 hDa, seguido de incubação por 30 minutos a temperatura ambiente. Após quatro ciclos de lavagens das placas, 100 uL do conjugado anti-IgG humano marcado com peroxidase foi adicionado, seguindo-se novamente 30 minutos de incubação e lavagens. O substrato enzimático constituído de H 2 O 2 e TMB (3, 3´,5, 5´ tetrametilbenzidina) foi adicionado e, após 15 minutos, a reação foi bloqueada e realizada a leitura espectro- fotométrica. O resultado semiquantitativo, expresso em U/ml, foi obtido conforme as instruções dos fabricantes, a partir de 5 pontos do padrão, de zero a 100 U/ml. Amostras com resultados supe- riores a 100 U/ml foram diluídas e retestadas. Os valores iguais ou acima de 10 U/ml foram considerados positivos.
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Association between CD14 gene polymorphisms and cancer risk: a meta-analysis.

Association between CD14 gene polymorphisms and cancer risk: a meta-analysis.

between the -260C/T polymorphism and risk of cancer in the population-based subgroup was found under recessive model. The results seem to contradict the observations of functional studies of CD14, which had suggested that CD14 played an important role in the development of cancer. Since carcinogenesis is a multistep process involving multifactorial interplay between genetic and environmental factors that involves various genetic alterations and several biological pathways. Thus, it is unlikely that risk factors of cancer work in isolation from each other. What’s more, the different linkage disequilibrium patterns usually exist in related genes and the influence of the genetic variant may be masked by other unidentified causal genes involved in carcinogenesis. In addition, only few studies on -651C/T polymorphism were included, which may also contribute to the result and it should be interpreted with caution.
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Helicobacter pylori infection in patients

Helicobacter pylori infection in patients

Whether the regression of gastric metaplasia in the duodenum can be achieved after eradication of Helicobacter pylori is not clear. The aim of the present study was to investigate the relationship between H. pylori infection and gastric metaplasia in patients with endoscopic diffuse nodular duodenitis. Eighty-six patients with endoscopically confirmed nodular duodenitis and 40 control patients with normal duodenal appearance were investigated. The H. pylori-positive pa- tients with duodenitis received anti-H. pylori triple therapy (20 mg omeprazole plus 250 mg clarithromycin and 400 mg metronidazole, all twice daily) for one week. A control endoscopy was performed 6 months after H. pylori treatment. The H. pylori-negative patients with duodenitis received 20 mg omeprazole once daily for 6 months and a control endoscopy was performed 2 weeks after treatment. The preva- lence of H. pylori infection was 58.1%, and the prevalence of gastric metaplasia was 57.0%. Seventy-six patients underwent endoscopy again. No influence on the endoscopic appearance of nodular duodenitis was found after eradication of H. pylori or acid suppression therapy. However, gastric metaplasia significantly decreased and complete regression was achieved in 15/28 patients (53.6%) 6 months after eradication of H. pylori, accompanied by significant improvement of other histological alterations. Only mild chronic inflammation, but not gastric metaplasia, was found in the control group, none with H. pylori infection in the duodenal bulb. Therefore, H. pylori infection is related to the extent of gastric metaplasia in the duodenum, but not to the presence of diffuse nodular duodenitis.
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Arq. Gastroenterol.  vol.47 número4

Arq. Gastroenterol. vol.47 número4

On Etest, one of these false-susceptible isolates grew several colonies within the inhibition ellipse. DNA extracted from these colonies, submitted to qPCR, showed an identical H. pylori genotype as that seen in direct qPCR assay. Mutant colonies were not seen in Etest ellipses of the two discrepant samples. Mutations sometimes involve a biologic cost; and bacterial itness can be affected negatively. Strains of Escherichia coli, which are furazolidone-resistant, grow at a lower rate than the susceptible isogenic parent when cultured without the drug (16) .

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SERVIÇO PÚBLICO FEDERAL UNIVERSIDADE FEDERAL DO PARÁ NÚCLEO DE MEDICINA TROPICAL PROGRAMA DE PÓS-GRADUAÇÃO EM DOENÇAS TROPICAIS

SERVIÇO PÚBLICO FEDERAL UNIVERSIDADE FEDERAL DO PARÁ NÚCLEO DE MEDICINA TROPICAL PROGRAMA DE PÓS-GRADUAÇÃO EM DOENÇAS TROPICAIS

Helicobacter pylori CagA cytotoxin, encoded by the cagA gene, has been associated with increased inflammatory response in gastric tissue and the change in control of cell growth and proliferation. Activation of this cytotoxin occurs by phosphorylation in specific tyrosine residues within an amino acid sequence termed motif EPIYA, four types of motifs are described in the literature (EPIYA-A,-B-C and D). However, the site EPIYA-C is the most common site of phosphorylation of CagA protein of the bacterial strains isolated in Western countries, may still be found in repetitions. This study aimed to determine the types of motifs EPIYA of CagA present in patients with gastritis and gastric cancer and its association with these diseases. Were collected samples from gastric biopsies of 384 patients infected with H. pylori, of this 194 presented chronic gastritis and 190 had gastric cancer. The gastric biopsy was used for bacterial DNA extraction and analysis of the cagA gene by PCR. The prevalence of gastric cancer occurs in males, mean age 58 years. The cagA gene was more prevalent in patients with gastric cancer, showing association with a higher degree of inflammation, neutrophil activity and development of intestinal metaplasia (OR = 4,31, IC 95% = 2,71-6,87, p <10 -3 ; OR = 3,57, IC 95% = 2,18 – 5,84, p <10 -3 ; OR =
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PREVALENCE OF HELICOBACTER PYLORI

PREVALENCE OF HELICOBACTER PYLORI

ABSTRACT: This study was done at Christian Medical College and Hospital, Ludhiana for the period of 5 years from January 2006 to December 2010 in the Department of Microbiology. A total of 306 endoscopic gastric biopsy specimens were collected from the suspected cases of the peptic ulcer and were subjected to rapid urease test for Helicobacter pylori. This test has high sensitivity and cent percent specificity. The prevalence was determined to be 09.48% and male: female ratio was determined to be 68.97:31.03.

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Helicobacter pylori : eficácia da terapêutica

Helicobacter pylori : eficácia da terapêutica

Introduction: The Helicobacter pylori has acquired great importance over the last decades, by being recognized as an important pathogen that infects a big part of human population. This bacteria, located in the gastric mucosa, presents a causal relation with some pathologies such as: gastric carcinoma, peptic ulcer, among others. The indications to the eradication of this bacterium remain controversial but it is consensual in some pathologies and its treatment represents a great challenge to doctors. The gradual increase of the failure of the treatment forces the use of new therapeutic schemes and to look for new solutions. The rates of efficiency of the eradication of the Helicobacter pylori have been diminishing as the resistance of the antibiotics, namely to clarithromycin, is increasing, becoming this way the main factor to the failure of treatment. The present dissertation intends to perform a systematic revision based on scientific publications related to the efficiency of the therapeutic of the eradication of Helicobacter pylori.
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RELAÇÃO ENTRE GRAUS DE ESOFAGITE E O HELICOBACTER PYLORI.

RELAÇÃO ENTRE GRAUS DE ESOFAGITE E O HELICOBACTER PYLORI.

ABSTRACT – Background: The Helicobacter pylori infection (HP) is related to the development of gastric lesions and lymphoma; however, it is not known if there is a relation with gastroesophageal reflux disease and reflux esophagitis. Aim: To evaluate HP’s relationship with esophagitis in patients undergoing upper endoscopy. Methods: Observational, retrospective and cross- sectional study, being evaluated 9576 patients undergoing outpatient endoscopic examination during the period between January and December 2015. Were included patients with any esophageal alteration at the examination; greater than 18; of both genders; independent of the complaint or the reason for the examination, illness or drug use. Were excluded those with active bleeding during the examination and in use of anticoagulants. The variables gender, age, esophagitis and result of the urease test, were studied. For statistical analysis was used the Epi Info software 7.1.5.2. Results: Most of the samples consisted of women and the overall average age was 46.54±16.32 years. The presence of infection was balanced for gender: 1204 (12.56%) women and 952 (13.92%) men. Relating degree of esophagitis HP- and HP+ was observed that the type A was the most common (58.79%, n=1460); 604 (24.32%) had grade B; 334 (13.45%) grade C, and 85 (3.42%) grade D. In the relation between the grade of esophagitis with gender, esophagitis A was predominant in women and present in 929 (63.33%), followed by type B, 282 (46.68%), 136 C (40.71%) and D 30 (35.29%). In men 531 (36.36%) showed type A, 322 (53.31%) B, 198 (59.28%) C, and 55 (64.70%) D. Among the groups 40-50 and over 60 years there was a significant difference in whether have or not have HP+. Conclusion: There is no significant difference between HP infection and the different grades of esophagitis. Correspondência:
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The inhibition of polo kinase by matrimony maintains G2 arrest in the meiotic cell cycle.

The inhibition of polo kinase by matrimony maintains G2 arrest in the meiotic cell cycle.

The data presented above demonstrate that Mtrm acts as a negative regulator of Polo during the later stages of G2 arrest during meiosis. Indeed, both the repression of Polo expres- sion until stage 11 and the inactivation of newly synthesized Polo by Mtrm until stage 13 play critical roles in maintaining and properly terminating G2 arrest. Our data suggest a model in which the eventual activation of Cdc25 by an excess of Polo at stage 13 triggers NEB and entry into prometaphase. Although our data do shed some light on the mechanism by which Mtrm inhibits Polo, it is not entirely clear whether Polo’s ability to phosphorylate targets other than Cdc25 might be blocked by Mtrm::Polo binding. These issues will need to be addressed in the future studies. Finally, we note that although small molecule inhibitors of Polo have been identified [36], Mtrm represents the first case of a protein Figure 9. A Model for the Control of NEB by Mtrm-Induced Inhibition of
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Clinics  vol.72 número3

Clinics vol.72 número3

In Asia, upper gastrointestinal cancers constitute a major group of malignancies with high rates of morbidity and mortality. The esophageal cancer belt, originating in the Far East and extending through middle Asia and the Near East, encompasses many countries, including northern China, northern Iran and the eastern part of Turkey (14). The pre- dominant histopathological type of esophageal cancer is the squamous cell type in the endemic Asian regions, with incidence rates that may vary 200-fold among different populations within the same defined region due to cultural practices. More than 80% of ESCC patients in the rural areas of Asia also present at advanced stages that are not amenable to curative therapies; hence the need for novel preventive strategies is urgent (15).
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Rev. Bras. Anestesiol.  vol.64 número2

Rev. Bras. Anestesiol. vol.64 número2

Las ciclodextrinas son moléculas utilizadas a menudo en las industrias alimentarias y farmacéuticas. También son muy usadas para convertir medicamentos lipofílicos en formas hidrofílicas, además de su uso en el campo de la microbiología. Algunas ciclodextrinas, como el dimetil- b-ciclodextrina, se usan para aumentar la producción de Helicobacter pylori (H. pylori) 12 , mientras que otras, como

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Rev. Bras. Hematol. Hemoter.  vol.32 número5

Rev. Bras. Hematol. Hemoter. vol.32 número5

Follicular lymphomas are a chronic lymphoproliferative B-phenotype-like disease (CD19, CD20, CD22 surface immunoglobulin) positive for CD10 and Bcl-6 antigens. It can be classified as grade 1 (<5 centroblasts), grade 2 (6-15 centroblasts), grade 3a (> 15 centroblasts + centrocytes) and grade 3b (arrays of centroblasts) but without demonstrating any relevant prognostic significance. Subtype 3b is closer to activated B-cell diffuse large B-cell lymphoma (DLBCL) than the other FL subgroups. (9)

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Treatment of low-grade gastric malt lymphoma using Helicobacter pylori eradication

Treatment of low-grade gastric malt lymphoma using Helicobacter pylori eradication

Uvod/Cilj. Limfom limfnog tkiva mukoze (MALT limfom) želuca najčešće nastaje kao posledica Helicobacter pylori (H. pylori) infekcije. Cilj studije bio je da se ispita dugotrajni efekat lečenja MALT limfoma želuca niskog stepena maligniteta eradikacijom H. pylori infekcije. Metode. U periodu od 2002. do 2012. godine kod 20 pacijenata sa simptomima dispepsije, prosečne starosti 55,1 godinu, endoskopski i histološki je di- jagnostikovan MALT limfom želuca u ranoj fazi. Histološki preparati endoskopskih biopsijskih uzoraka bojeni su klasič- nom hematoksilin-eozin (HE) metodom, histohemijskim i imunohistohemijskim metodama. Rezultati. Endoskopski nalaz gastritisa imalo je 25% bolesnika, dok je 75% bolesnika imalo hipetrofiju nabora, jaku hiperemiju mukoze, fragilnost, nodularnost, egzulceracije i rigiditet. Patohistološki, patog- nomoničan dijagnostički kriterijum bila je infiltracija i razara- nje žlezdanog epitela neoplastičnim limfoidnim ćelijama, od- nosno limfoepitelijalna lezija. Kod svih 20 bolesnika bio je ve- rifikovan H. pylori brzim ureaza testom i modifikovanom Gi- emsa metodom. Nakon trojne eradikacione terapije potpuna remisija MALT limfoma postignuta je kod 85% bolesnika, bez recidiva limfoma i H. pylori infekcije u prosečnom periodu praćenja od 48 meseci. Kod 3 (15%) bolesnika nije došlo do remisije MALT limfoma 12 meseci od eradikacione terapije. Kod dva od ova tri bolesnika došlo je do progresije MALT limfoma u difuzni krupno ćelijski limfom. Zaklju čak. Pot- puna dugotrajna remisija MALT limfoma želuca niskog stepena maligniteta postiže se u visokom procentu posle eradikacije H. pylori infekcije. Na taj način sprečava se nas- tanak difuznog krupnoćelijskog limfoma, kao i adenokar- cinoma želuca.
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Genes associados à virulência de Helicobacter pylori

Genes associados à virulência de Helicobacter pylori

Alguns genótipos mais virulentos já são bem descritos, como os genes vac A e cag A, entretanto não são suficientes para explicar a associação dessa bactéria com doenças gastrointestina[r]

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A INFECÇÃO POR Helicobacter pylori EM POPULAÇÕES DE ANGOLA

A INFECÇÃO POR Helicobacter pylori EM POPULAÇÕES DE ANGOLA

McCarthy demonstrou uma melhoria dos sintomas às 4 semanas após a terapêutica de erradicação, mesmo nos doentes que se mantiveram H. pylori positivos. Ao fim de um ano, na avaliação sintomática, os doentes com erradicação apresentaram um quadro estatístico de controlo sintomático inferior aos que não tinham feito a erradicação (77). Também Moayeddi publicou um estudo em 2.500 doentes com dispepsia funcional, onde concluiu que aos 6-12 meses, as queixas dispépticas eram inferiores a 9% nos doentes submetidos a terapêutica para a erradicação da infecção por H. pylori (91). A azia, tosse irritativa, sensação de queimação na região retroesternal, inicialmente interpretada como Doença do Refluxo Gastresofágico (DRG), deve também ser entendido, como hiperprodução ácida, hipersensibilidade da mucosa no contexto da diminuição da barreira de defesa constituída pelo muco e prostaglandinas resultante da infecção. Porém não existe consenso na associação etiológica da infecção por H. pylori e a DRG. Chegando a questionar-se o seu papel protector nesta patologia por induzir a uma baixa produção ácida e quando da sua erradicação normalizar-se.
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