Human Alveolar Wall Fibroblasts Directly Link Epithelial Type 2 Cells to Capillary Endothelium
Bibliographic record
Abstract
Alveolar wall fibroblasts directly link type 2 (T2) pneumocytes to capillary endothelium through apertures in their respective basal laminae in rabbit lung. These fibroblasts provide a bridge from the capillary to the airway lumen along which leukocytes may migrate without disrupting extracellular matrix. Normal human lungs were examined by transmission electron microscopy and serial section 3D reconstruction. We found contacts between fibroblasts and T2 pneumocytes and between fibroblasts and type 1 pneumocytes that occur at holes in the epithelial basal lamina. The same fibroblast also made contact with pericytes and endothelial cells through similar apertures. A survey of 41 T2 pneumocytes revealed that 54% of T2 pneumocytes had at least one gap in their basal lamina. A morphometric analysis showed these gaps occupied approximately 5.58 +/- 1.51% (mean +/- SE) of the area underneath T2 pneumocytes. We conclude that a population of single fibroblasts link T2 pneumocytes to adjacent capillary endothelial cells in alveolar walls of human lung. We propose that fibroblasts are organized to maintain communication between epithelium and mesenchyme and to provide directional information to migrating leukocytes.
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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 | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".