Tc99m-annexin V-128 SPECT imaging of listeriosis in mice
Bibliographic record
Abstract
1224 Objectives Ultrasound, CT, and MRI, currently the preferred imaging modalities to localize sites of infection, have low sensitivity and specificity in the setting of systemic bacterial disease. Here, we evaluate Tc99m annexin V-128, an in vivo marker of apoptosis, for SPECT imaging of disseminated bacterial infection, using a well-described mouse model that employs bioluminescent Listeria monocytogenes. Methods Mice were inoculated intravenously with bioluminescent Listeria, and in vivo bioluminescence imaging (BLI) was used to assess the location and extent of infection. Tc99m-annexin V-128 was then injected for SPECT imaging, and the two sets of images were correlated. Splenocytes of infected and uninfected mice were characterized for annexin binding by flow cytometry. In addition, treatment of the infection with ampicillin was imaged with BLI and Tc99m annexin V SPECT. Results Signals from BLI and Tc99m-annexin V-128 SPECT co-localized within the spleen and other organs. Decreases in Tc99m-annexin V-128 uptake and BLI signal within the spleen directly reflected the reduction of bacterial infection by ampicillin treatment [median spleen/median renal uptake of Tc99m-annexin V-128; low bacterial inoculum = 0.404 ± 0.053 (n = 7) vs. Rx = 0.225 ± 0.141 (n = 3), *p = 0.0153; high bacterial inoculum = 0.847 ± 0.301 (n = 5) vs. Rx = 0.291 ± 0.076 (n = 4), **p = 0.0093; control spleen = 0.104 ± 0.047 (n = 6)]. Autoradiography of spleens excised from the imaged mice revealed multifocal patterns of Tc99m-annexin V-128 uptake. Granulocytes and macrophages exhibiting IAF-annexin V-128 binding were increased in number in the infected spleen. In addition to the spleen, there were several other anatomic sites where a correlation between BLI and annexin V SPECT signals was observed. Conclusions Tc99m-annexin V-128 SPECT allowed for the detection and monitoring of disseminated bacterial infection and treatment in mice. Tc99m-annexin V-128 may be of use for the assessment of bacterial spread in sepsis or other disseminated bacterial infections. Research Support Gift funding from Atreus Pharmaceuticals/Ottawa Canada
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".