CagA and VacA<i>Helicobacter Pylori</i>Antibodies in Gastric Cancer
Bibliographic record
Abstract
BACKGROUND: Infection with different genotypes of virulent Helicobacter pylori strains (cytotoxin-associated gene A [CagA]- and/or vacuolating cytotoxin A [VacA]-positive) can play a role in the development of atrophic gastritis, duodenal ulcer (DU) and gastric cancer (GC). OBJECTIVE: To determine whether patients with GC and H pylori-negative histological staining had previously been infected with H pylori CagA- and/or VacA-positive virulent strains. METHODS: Twenty-three GC patients with a mean (+/- SD) age of 68.14+/-9.8 years who tested H pylori-negative on histological staining took part in the study. Three control groups were included. The first group comprised 19 patients with past H pylori infection and DUs eradicated 10 years earlier, with a mean age of 58+/-18.2 years. H pylori-negative status for this group was determined every year with Giemsa staining, and follow-up testing occured 120+/-32 months (mean +/- SD) after therapy. The subsequent control groups included 20 asymptomatic children, with a mean age of 7+/-4.47 years, and with H pylori-negative fecal tests; the final group contained 30 patients without clinical symptoms of H pylori infection, with a mean age of 68+/-11.6 years, who tested H pylori-negative by histological staining. RESULTS: Prevalence of CagA and VacA seropositivity, respectively was 82.6% and 73.91% in GC patients; 84.2% and 84.2% in H pylori-negative DU patients; 25% and 5% in H pylori-negative children; and 36.6% and 16.6% in the patients without clinical symptoms on histological staining. CagA and VacA antibody positivity was not significantly different between GC patients and patients with DUs that had been eradicated 10 years earlier. Significant positivity was found between the children's group and the H pylori-negative (with past DUs) group (P<0.001). A statistically significant difference was found in age between groups (P<0.03). CONCLUSIONS: Patients with GC, even when H pylori-negative at the time of the present study, may have been infected by H pylori before the onset of the disease, as confirmed by CagA and VacA seropositivity. These data reinforce the hypothesis that H pylori may be a direct carcinogenic agent of GC.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".