Patch test–relevant concentrations of metal salts cause localized cytotoxicity, including apoptosis, in skin ex vivo
Bibliographic record
Abstract
BACKGROUND: Metal alloys containing contact sensitizers (nickel, palladium, titanium) are extensively used in medical devices, in particular dentistry and orthopaedic surgery. The skin patch test is used to test for metal allergy. OBJECTIVE: To determine whether metal salts, when applied to freshly excised skin at patch test-relevant concentrations and using a method which mimics skin patch testing, cause in changes in the epidermis and dermis. METHODS: Tissue histology, apoptosis, metabolic activity, and inflammatory cytokine release were determined for two nickel salts, two palladium salts, and four titanium salts. RESULTS: Patch test-relevant concentrations of all metal salts caused localized cytotoxicity. This was observed as epidermis separation at the basement membrane zone, formation of vacuoles, apoptotic nuclei, decreased metabolic activity, and (pro)inflammatory cytokine release. Nickel(II) sulfate hexahydrate, nickel(II) chloride hexahydrate, titanium(IV) bis(ammonium lactato)dihydroxide, and calcium titanate were highly cytotoxic. Palladium(II) chloride, sodium tetrachloropalladate(II), titanium(IV) isopropoxide, and titanium(IV) dioxide showed mild cytotoxicity. CONCLUSION: The patch test in itself may be damaging to the skin of the patient being tested. These results need further verification with biopsies obtained during clinical patch testing. The future challenge is to remain above the elicitation threshold at noncytotoxic metal concentrations.
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 | 0.000 |
| 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) | 0.004 | 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".