Sex Differences of Brain Serotonin Synthesis in Patients with Irritable Bowel Syndrome Using α-[<sup>11</sup>C]methyl-L-tryptophan, Positron Emission Tomography and Statistical Parametric Mapping
Bibliographic record
Abstract
BACKGROUND: Irritable bowel syndrome (IBS) is the most common functional bowel disorder and has a strong predominance in women. Recent data suggest that the brain may play an important role in the pathophysiology of IBS in the brain-gut axis. It is strongly suspected that serotonin (5-HT), a neurotransmitter found in the brain and gut, may be related to the pathophysiology of IBS. It is reported that a 5-HT3 antagonist is effective only in female patients with diarrhea-predominant IBS. OBJECTIVE: In the present study, 5-HT synthesis was measured using positron emission tomography, with alpha-[11C]methyl-L-tryptophan as the tracer, in patients with IBS. The aim of the present study was to compare 5-HT synthesis in the IBS patients with that in the controls, and to compare 5-HT synthesis between male and female IBS patients. METHODS: Six male and six female nonconstipated IBS patients were scanned. Age-matched healthy volunteers were scanned as controls. Eighty minute dynamic scans were performed. Functional 5-HT synthesis images were analyzed using statistical parametric mapping. RESULTS: 5-HT synthesis was greater only in the female IBS patients in the right medial temporal gyrus (multimodal sensory association cortex) compared with the female controls (P<0.001). CONCLUSIONS: The greater brain 5-HT synthesis in the female IBS patients than in the controls may be related to the pathological visceral pain processing of the IBS patients, a larger female predominance of the disorder, and the sex difference of the efficacy of the 5-HT3 antagonist in treatment.
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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 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".