Increased plasma glutamate, glycine, and arginine levels in complex regional pain syndrome type 1
Bibliographic record
Abstract
BACKGROUND: Various inflammatory mediators have been identified as potential contributors to complex regional pain syndrome type 1 (CRPS1), but these mediators do not entirely explain certain manifestations of the syndrome, such as pain. The objective of this study was to investigate the role of amino acids in the pathogenesis of CRPS1. METHODS: We used HPLC to determine plasma concentrations of 16 amino acids, especially those related to the NMDA receptor (e.g., glutamate and glycine) and nitric oxide (NO) synthesis (e.g., arginine and citrulline) in patients with CRPS1 (n=64) and age- and sex-matched healthy controls (n=51). Patients rated pain intensity (visual analog scale) and the subjective experience of pain intensity (McGill Pain Questionnaire). Psychological dysfunction was assessed using the SCL-90. RESULTS: Relative to controls, in CRPS1 patients, plasma levels of glutamate, arginine, taurine, and glycine were increased, and plasma levels of glutamine and the ratio of citrulline to arginine were decreased. Remarkably, in CRPS1 patients there was a highly significant inverse correlation between glutamine and glutamate, although the sum of molar concentrations of glutamate and glutamine remains unchanged. Subjective measures of pain and indicators of psychoneuroticism and emotional instability did not correlate with amino acid levels. CONCLUSION: This study shows for the first time a pronounced increase in amino acid levels in this chronic pain syndrome. The marked differences in glutamate, glutamine, glycine, taurine and arginine levels between patients and controls suggest the involvement of both the NDMA receptor and the endothelium-dependent arginine-NO system in CRPS1.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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 teacher head, 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".