Evaluation of three commercial enzyme-linked immunosorbent assay kits for diagnosis of Helicobacter pylori in Chinese patients

Most of the commercial serological assays for H. pylori are developed and validated in western countries. We evaluated the accuracy of three popular commercial ELISA tests for H. pylori in the Chinese population. Eighty dyspeptic patients were recruited and diagnosis of H. pylori infection was based on biopsy urease test, histology and urea breath test. Thirty-six patients (45%) were positive for H. pylori infection by two or more positive reference tests. Anti-H. pylori IgG antibody was detected by three commercial ELISA tests: GAP IgG (Bio-Rad), HM-CAP (Enteric Products) and Pyloriset EIA-G (Orion). The respective sensitivity, specificity, positive and negative predictive values of the three tests were: GAP IgG (50%, 97.4%, 93.8%, 71.7%), HM-CAP (72.7%, 68.4%, 66.7%, 74.3%) and Pyloriset EIA-G (75%, 86.4%, 81.8%, 80.9%). Despite the high accuracy reported in the West, the performance of these commercial serological tests was unsatisfactory when used in Chinese patients. Copyright (C) 1999 Elsevier Science Inc.link_to_subscribed_fulltex

Biliary IgA secretion in obstructive jaundice: The effects of endoscopic drainage

Background: Immunoglobulin A is the predominant immunoglobulin in the bile. Data on the effects of biliary obstruction on IgA secretion are few. Methods: The serum and bile IgA levels in patients with common duct stones (n = 27) or with malignant obstructive jaundice (n = 20) were collected by insertion of nasobiliary catheters. Single samples of common duct bile from patients with gallstones (n = 24) were collected as controls. Bile samples collected were measured for total IgA, secretory IgA, and free secretory component levels by sandwich enzyme-linked immunosorbent assays. Results: Bile total IgA, secretory IgA, and free secretory component in the common duct stones group (82.7 ± 11.4 μg/ml, 18.4 ± 1.7 μg/ml, 0.74 ± 0.15 μg/ml) and the malignant obstructive jaundice group (81.6 ± 10.7 μg/ml, 18.2 ± 2.4 μg/ml, 0.57 ± 0.12 μg/ml) were found to be significantly lower than those of the control gallstone patients (104.8 ± 3.4 μg/ml, 33.2 ± 2.9 μg/ml, 1.03 ± 0.12 μg/ml) (P < 0.05). Serum secretory IgA levels in the common duct stones (26.53 ± 1.75 μg/ml) and malignant obstructive jaundice groups (26.03 ± 3.48 μg/ml) were significantly higher than the gallstone group (18.45 ± 4.56 μg/ml). The bile-to-serum concentration ratio of total IgA, secretory IgA, and free secretory component levels rose significantly within 48 hours after relief of obstruction. Conclusions: Biliary obstruction secondary to both calculus or malignancy of the hepatobiliary system causes suppression of bile IgA secretion and elevated serum level of secretory IgA. Bile secretory IgA secretion recovers with endoscopic drainage of the obstructed system.link_to_subscribed_fulltex

Upregulation of heme oxygenase-1 and p21 confers resistance to apoptosis in human gastric cancer cells

Both heme oxygenase-1 (HO-1) and p21 WAF1/Cip1 (p21) are involved in the pathogenesis of human cancer and their functions are closely associated with apoptosis. However, how these two molecules regulate apoptosis in human gastric cancer is unknown. In this study, we studied how HO-1 and p21 were regulated in two gastric cancer cell lines, MKN-45 with wild p53 and MKN-28 with mutant p53. The cells were treated with hemin and cadmium to induce HO-1. The result showed that HO-1 protein was significantly induced by hemin and cadmium in both cells tested. Following the HO-1 expression, p21 level was also markedly induced. The cells with increased HO-1 and p21 showed obviously resistantance to apoptotic stimuli. The levels of HO-1 and p21 induced were significantly inhibited by p38 mitogen-activated protein kinase (p38 MAPK) inhibitor (SB203580) and extracellular-regulated kinase (ERK) inhibitor (PD098059). Parallel to decreased HO-1 and p21 expression, the kinase inhibitors also significantly attenuated the resistance of the cells to apoptosis. The elevated HO-1 and p21 was further found to be associated with increase activity of the nuclear NF-κB and the inhibition of NF-κB led to the block of their induction. The elevated HO-1 and p21 were also demonstrated to be related to increased cellular inhibitor of caspase inbitory protein-2 (c-IAP2) and decreased caspapse-3 activity. It was noted that the above changes observed were not different between MKN-45 and MKN-28 cells, suggesting the functions of HO-1 and p21 were irrespective of the status of p53. In conclusion, we demonstrate that the resistance to apoptosis in gastric cancer cells with elevated HO-1 and p21 is independent of p53 status in a p38 MAPK- and ERK-mediated pathway with elevated C-IAP2 and decreased caspase-3 activity and that this pathway is sensitive to the inhibition of NF-κB.link_to_subscribed_fulltex

Interaction of Helicobacter pylori eradication and non-steroidal anti-inflammatory drugs on gastric epithelial apoptosis and proliferation: Implications on ulcerogenesis

Background: Apoptosis is associated with loss of gastric mucosal integrity and may play an important role in ulcer development. Aim: To examine how Helicobacter pylori and NSAIDs interact to effect apoptosis and proliferation of the gastric mucosa. Methods: Patients presenting with musculoskeletal pain requiring NSAID treatment and without previous exposure to NSAID or pre-existing ulcers were recruited. Patients were divided into three groups: (A) H. pylori-infected; (B) H. pylori-eradicated; and (C) non-infected patients. They were given naproxen for 8 weeks. Patients with non-ulcer dyspepsia and H. pylori infection who were given anti-Helicobacter therapy were recruited as controls (D). Endoscopy was performed at baseline and 8-weeks after receiving naproxen. Gastric antral biopsies were obtained to assess apoptosis by terminal uridine deoxynucleotidyl nick end-labelling (TUNEL) and proliferation by Ki67 immunostaining. Results: A total of 55 patients were studied. H. pylori-positive patients had a higher apoptosis and proliferation index at baseline than non-infected patients (P < 0.0001), and eradication of H. pylori resulted in a significant reduction in these parameters. The NSAID induced apoptosis in non-infected subjects (P = 0.03) whilst apoptosis was reduced in H. pylori-positive patients receiving NSAID (P = 0.02). After 8 weeks of NSAID, post-treatment apoptosis was significantly higher in patients with persistent H. pylori infection than in non-infected patients (P = 0.01). Conclusions: Eradication of H. pylori prior to NSAID therapy significantly reduces the level of apoptosis in the gastric mucosa, which may contribute to maintaining mucosa integrity and preventing ulcer development.link_to_subscribed_fulltex

Validation of a new immunoblot assay for the diagnosis of Helicobacter pylori in the Asian population

Background: Performance of commercial serological tests for Helicobacter pylori varies in different populations, largely due to strain heterogeneity and variations in antigenic preparations. Currently available serology tests often show sub-optimal accuracy when used for Asian patients. Aim: This study evaluated a recombinant antigen-based immunoblot for the diagnosis of H. pylori infection in Chinese patients, and compared it with a conventional ELISA test. Methods: Dyspeptic patients referred for diagnostic endoscopy were recruited. The gold standard for H. pylori infection was based on two or more positive results among rapid urease test, histology and 13C-urea breath test. Serological diagnosis of H. pylori infection was conducted by an ELISA test (pylori DTect; Diagnostic Technology) and an immunoblotting against a novel recombinant antigen (C1S; Genelab), which was constructed by immunological screening of the genomic DNA library of H. pylori. Results: A total of 87 patients were evaluated and H. pylori infection was diagnosed in 40 (46%) by the reference tests. The sensitivities of the ELISA and immunoblot were 80% (95% CI: 64-91%) and 90% (95% CI: 76-97%), whilst the specificities were 96% (95% CI: 86-96%) and 87% (95% CI: 74-95%), respectively. The respective likelihood ratios of the two tests were 18.6 and 7.0. Conclusions: Satisfactory performance is obtained by the use of the new recombinant antigen-based immunoblot for diagnosing H. pylori infection in Chinese patients.link_to_subscribed_fulltex

Prevalence of sleep disturbances during COVID-19 outbreak in an urban Chinese population : a cross-sectional study

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