Human Kallikrein 13 Expression in Normal Tissues: An Immunohistochemical Study
Bibliographic record
Abstract
The human tissue kallikrein 13 gene (KLK13), encoding for hK13 protein, was recently cloned and characterized. Here we describe the immunohistochemical (IHC) localization of hK13 in normal human tissues and compare it with the expression of two other kallikreins, hK6 and hK10. We performed the streptavidin-biotin IHC method on 204 paraffin blocks from archival, current, and autopsy material prepared from almost every normal human tissue, using a polyclonal and a monoclonal hK13 antibody. The staining was cytoplasmic and both antibodies yielded similar results. The hK13 protein was revealed in a variety of tissues, mainly in glandular epithelia. Other epithelia that expressed hK13 included the urothelium, the spermatic epithelium, and the epithelium of the choroid plexus. hK13 was intensely immunoexpressed by some endocrine organs, such as the adenohypophysis, the thyroid gland, the parathyroid glands, the adrenal medulla, the Leydig cells of the testis, and the cells of the endocrine pancreas. Immunoreactivity was also observed in the primordial follicles, the corpus luteum, and sparse luteinized cells in the stroma of the ovary, the trophoblastic cells of the placenta, the Hassall's corpuscles of the thymus, and chondrocytes. Nerves and ganglia of the peripheral nervous system, and both neurons and glial cells in the central nervous system, were positive. In short, hK13 was expressed by many glandular epithelia, some endocrine organs, and some specialized epithelia and cells. Comparison of these data with hK6 and hK10 expression suggests that the three kallikreins have a similar IHC pattern in normal human tissues.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.000 | 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".