pylori (188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis), among those who were submitted to endoscopy to clarify
the origin of symptoms related to the upper gastrointestinal tract or who underwent gastric surgery to remove gastric carcinoma at the University Hospital/UFMG, Luxemburgo, and Mário Penna Hospitals, in Belo Horizonte, check details Brazil. Most of the included individuals (>80%) were of low socioeconomic level with similar cultural habits, and all were native LY2606368 research buy of Minas Gerais state with the same ethnic background, approximately 33% of Portuguese, 33% of Amerindian and 33% of African ancestry, homogeneously present in each subject [29]. The study was approved by the institutional Ethics Committees and informed consent was obtained from all patients. The transport, culture, and microbiological identification of the bacterial isolates were performed as previously described [34, 35]. Histology In the group
of gastritis and duodenal ulcer patients, endoscopic biopsy samples of the antral and oxyntic gastric mucosa were obtained for histological and microbiological study. Antral and oxyntic biopsy specimens were fixed in 10% formalin and embedded in paraffin wax, and 4-μm-thick histological sections were stained with carbolfuchsin for H. pylori investigation [35] and hematoxycilin and eosin for histological evaluation according to the updated Sydney System [36]. In the group of gastric selleck inhibitor cancer patients, the fragments were obtained from the stomach removed by gastrectomy after opening it along the greater curvature within one hour of resection. The tumour was classified according to Lauren [37]. Extraction of bacterial DNA Bacterium DNA obtained from 60 mm Petri dish growth was extracted using the QIAmp (QIAGEN, Hilden, Germany) kit according to manufacturer’s recommendations with minor modifications. Distilled water was used as a reaction
control. The DNA concentration was determined by spectrophotometry using NanoDrop 2000 (Thermo Scientific, Wilmington, NC) and stored at -20°C until use. Amplification of H. pylori-specific ureA and 16S rRNA genes The presence of specific ureA and 16S rRNA genes was evaluated according to Clayton et al. [38] and Fox et al. [39] respectively. The standard Tx30a H. pylori strain was used as a positive control, and Branched chain aminotransferase an Escherichia coli strain and distilled water were both used as negative controls. The thermocycler GeneAmp PCR System 9700 (Applied Biosystems, Foster City, CA) was used for all reactions. The amplified products were electrophoresed in 2% agarose gel, stained with ethidium bromide, and analyzed in an ultraviolet light transilluminator. Amplification of the cagA gene The cagA gene was amplified by means of two previously described primer pairs [40, 41]. A H. pylori strain from our collection (1010-95), known to be cagA-positive, was used as a positive control, and Tx30a H.