[Investigation of Helicobacter pylori iceA1 and iceA2 genes in patients with chronic gastritis and gastric cancer]. / Kronik Gastrit ve Gastrik Kanserli Hastalarda Helicobacter pylori iceA1 ve iceA2 Genlerinin Arastirilmasi

Several virulence factors of Helicobacter pylori play crucial role in the pathogenesis of the infections.H.pylori iceA gene which is induced by the contact with epithelium during the attachment of bacterium to the gastric mucosa, possess two variants (iceA1 and iceA2). Although there are some data indicating the relationship between H.pylori iceA1 and peptic ulcer, this concept is still controversial. The aims of this study were to investigate the presence and prevalence of H.pylori iceA1 and iceA2 gene regions in the tissue samples of patients diagnosed as chronic gastritis and gastric cancer, and to evaluate whether any correlation existed between these genotypes and clinical manifestations. A total of 109 tissue samples obtained from chronic gastritis (n= 55) and gastric cancer (n= 54) patients whose H.pylori infections have been confirmed by histopathologic examination of biopsy samples, were included in the study. The presence of H.pylori in the samples were also confirmed by amplification of the ureA gene region by inhouse polymerase chain reaction (PCR). H.pylori iceA1 and iceA2 genes were directly genotyped with the use of specific primers in the gastric biopsy specimens by PCR. The total positivity rates of iceA1 and ice- A2 genotypes in patients were found as 58% (63/109) and 24% (26/109), respectively. With the special attention to chronic gastritis and gastric cancer patients, the frequencies of iceA1 gene were 51% (28/55) and 65% (35/54), while the frequencies of iceA2 gene were 20% (11/55) and 28% (15/54), respectively. The difference of positivity rates of iceA1 and iceA2 genotypes between the patient groups were not statistically significant (p> 0.05). There was also no statistically significant correlation between the genotypes and clinical manifestation (r> 0.01). As a result, H.pylori iceA1 genotype was predominant (58%) in chronic gastritis and gastric cancer patients in our region, however the prevalence of iceA2 genotype was lower (24%) similar to those data reported in the literature. Our results supported the concept that iceA gene reflects geographical differences rather than determining the clinical picture and virulence. In conclusion, multicenter and large scaled studies are needed for better evaluation of H.pylori iceA gene and disease relationship.

Five methods for detection of Helicobacter pylori in the Turkish population.

AIM: To compare culture analysis, Helicobacter pylori (H. pylori) stool antigen (HpSA) test, polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) for H. pylori detection. METHODS: One hundred and thirty-two consecutive adult dyspeptic patients receiving diagnostic endoscopy at the department of gastroenterology were enrolled in this study. Culture and histological examination were performed on biopsy specimens. PCR and FISH tests were applied to histopathological samples. Stool samples that were simultaneously collected were tested for the H. pylori antigen using the HpSA test and bacterial DNA using stool PCR. RESULTS: H. pylori was positively identified by histological examination in 85/132 (64.4%) of the patients, while positive samples were found in 56 (42.4%), 64 (48.5%), 98 (74.2%), 28 (21.2%) and 81 (61.4%) of the patients by culture, HpSA, PCR, stool PCR and FISH methods, respectively. The results of the culture, biopsy PCR, HpSA and FISH tests, with the exception of the stool PCR, were found to correlate with the histological examination as a gold standard. CONCLUSION: The HpSA test is a rapid, simple, and noninvasive test for monitoring therapy. FISH is an accurate, rapid, cost-effective, and easy-to-use test for H. pylori detection.

Prevalence of cagA and vacA genotypes of Helicobacter pylori isolated from Turkish patients with active or non-active chronic gastritis.

Several virulence factors of Helicobacter pylori may contribute to gastric mucosal damage. In this study, the prevalence of cagA and vacA genotypes of H. pylori was examined in different patterns of chronic gastritis. Oesophagogastroendoscopy was performed in 147 dyspeptic patients. Antrum biopsies were obtained for isolation of H. pylori and for histopathological assessment. H. pylori vacAs1 and cagA genes were directly genotyped in the gastric biopsy specimens by polymerase chain reaction (PCR). A total of 102 dyspeptic patients, all H. pylori-positive by PCR, were included in the study. Of these, 59 had active chronic gastritis and 37 had non-active chronic gastritis. The prevalence of cagA and vacAs1 was higher among patients with active chronic gastritis than among those with non-active chronic gastritis (45.8% vs 21.6% (p = 0.02) and 78.0% vs 40.5% (p < 0.001), respectively). In conclusion, both cagA and vacAs1 genotypes are associated with the activity of chronic gastritis.

Novel approach for the prevention of contrast nephropathy.

OBJECTIVE: To date, there is no effective treatment of contrast medium (CM)-induced nephropathy. Multiple studies documented a protective role of hydration and N-acetylcystein (NAC) as prophylactic agents against CM-induced nephropathy in a high-risk population. In the present study, we investigated a new antioxidant agent, caffeic acid phenethyl ester (CAPE), and compare with NAC against contrast nephropathy. METHODS: Forty-two adult male rats were divided into six experimental groups, which were control, injected with intravenous (i.v.) CM, injected with i.p. CAPE, injected with i.p. NAC, injected with i.v. CM pretreated with i.p. CAPE, injected with i.v. CM pretreated with i.p. NAC. CAPE and NAC were given daily throughout the study. All rats were deprived of water for 24h at the third day of the study and then contrast medium was administered to CM, CAPECM and NACCM groups. The rats were sacrificed at the fifth day. Oxidant-antioxidant status was determined in renal tissues. The severity of injury was scored with a light microscope in renal tissue. Plasma creatinine levels were measured. RESULTS: Renal injury scores were higher in CAPECM and NACCM groups than in control, CAPE and NAC groups, but lower than the CM group. Likewise, creatinine levels of CAPECM and NACCM groups were higher than the control groups but they were significantly lower than the level of the CM group. Creatinine levels of the NACCM group were significantly higher than the CAPECM group. Malondialdehyde levels were significantly lower in CAPECM and NACCM groups than the CM group. CONCLUSION: CAPE might protect renal structure and functions as well as NAC against CM injury.

Does Helicobacter pylori-induced inflammation of gastric mucosa determine the severity of symptoms in functional dyspepsia?

BACKGROUND: Inflammation induces some structural and biochemical alterations and oxidative damage in gastric tissue. In this study, we aimed to investigate the relationship among the severity of symptoms, oxidative stress, and grading scales of Helicobacter pylori-induced gastric inflammation in functional dyspepsia. METHODS: Thirty-five patients with functional dyspepsia were enrolled in the study. The severity of dyspepsia within the last 6 months was evaluated by Glasgow Dyspepsia Severity Score. In biopsy specimens of gastric mucosa, severity of gastritis was estimated by the revised Sydney Classification System, and oxidative stress parameters were studied. RESULTS: Although there was no statistically significant relationship between symptom scores and degree of chronic inflammation, a tendency for symptoms to be more severe has been observed in low levels of gastritis. Levels of sulfhydryl groups were lower in subjects with high levels of chronic inflammation, and Helicobacter pylori intensity (P < 0.001 and P = 0.02, respectively). Levels of malondialdehyde were higher in subjects with high levels of chronic inflammation (P = 0.04). There was a statistically significant but a weak positive correlation between symptom scores and sulfhydryl levels (P < 0.001, r = 0.323). CONCLUSIONS: In conclusion, there may be an inverse relation between severity of symptoms and level of Helicobacter pylori induced gastric inflammation or oxidative stress in patients with functional dyspepsia.

[Investigation of hemodialysis patients in terms of the presence of occult hepatitis B]. / Hemodiyaliz hastalarinin gizli hepatit B varligi yönünden arastirilmasi.

The presence of hepatitis B virus (HBV) DNA in case of negative HBV surface antigen (HBsAg) in serum is known as "occult hepatitis B". There are many reports indicating that occult HBV infections are more frequently encountered in case of hepatocellular carcinoma, hemodialysis practice and co-infections with hepatitis C virus (HCV). The aim of this study was to investigate the presence of HBV-DNA in HBsAg negative hemodialysis. patients and subjects who had never experienced hemodialysis. A total of 226 HBsAg negative sera were included to the study, of which 153 were from hemodialysis patients (97 male, 56 female; mean age: 41.3 +/- 5.8 years), and 73 were from non-hemodialyzed individuals (46 male, 27 female; mean age: 36.5 +/- 6.9 years) who had serological evidence of previous HBV and HCV infections. Of these 73 subjects, 41 were anti-HCV positive, 22 were "anti-HBc IgG positive alone", seven were anti-HBc IgG and anti-HBs positive, and three were anti-HBc IgG and anti-HBe positive, while 40 of 153 (26.1%) hemodialysis patients were anti-HCV positive. HBV and HCV markers were detected by commercial enzyme immunoassays (bioMerieux, France and Murex, UK, respectively), and HBV-DNA testing was performed by a commercial real-time polymerase chain reaction (PCR; 5700 and 7700 Sequence Detection System, Applied Biosystems, UK) assay. Nineteen (12.4%) of HBsAg-negative hemodialysis patients and five (6.8%) of the non-hemodialyzed subjects were found positive for HBV-DNA (viral loads were > or =10(4) copies/ml, and 10(3)-10(4) copies/ml, repectively). The rates of occult HBV infection in the anti-HCV positive hemodialysis patients and anti-HCV positive non-hemodialyzed subjects were detected as 27.5% (11/40) and 2.4% (1/41), respectively. These rates in the other groups were found as follows; 7.1% (8/113) in the anti-HCV negative hemodialysis patients, 9.1% (2/22) in the "anti-HBc positive alone" subjects, and 20% (2/10) in the subjects positive for anti-HBc+anti-HBs or anti-HBe. The results of this study indicated that the prevalence of HBV viremia (12.4%) in hemodialysis patients being more prominent in those of anti-HCV positive patients (27.5%) should not be overlooked. In conclusion, the hemodialysis patients should be screened by sensitive PCR-based methods for occult HBV infections, even if they were negative for HBsAg, in order to prevent or at least to decrease the transmission risk of HBV infection which is still an important health problem in dialysis units.