“Repair cells” in equine uterine cytologic and histologic specimens.

The study investigates the response of horse uterine cells to catheterization, particularly, the emergence of “repair cells”. The paper challenges previously accepted beliefs about these cells, hypothesizing instead that they are damaged, rather than regenerating.

Objective and Methodology

• The basis for this research was the observation of ‘repair cells’ within uterine cytology specimens from infertile mares treated with antibiotics via indwelling uterine catheters.
• To understand the role of these ‘repair cells’, researchers initiated a study examining the effects of indwelling catheterization without antibiotic treatment.
• The study was carried out using equine uterine cytologic and biopsy specimens examined via light and electron microscopic tools.

Findings

• At the outset of the study, both the cytologic and biopsy specimens exhibited characteristics within normal limits, which changed upon indwelling catheterization.
• Five days post-catheterization, researchers noted the presence of neutrophils, a type of immune cell, within both the cytologic and biopsy specimens.
• The cytologic specimens also showed several groups of ‘repair cells’, and examination of similar cells within biopsy specimens suggested this was a localized response.
• The ‘repair cells’ had distinct traits like large nuclei and prominent nucleoli, suggesting cellular proliferation or regeneration.

Contradicting Observations

• Despite the perceived signs of proliferation, there was an ultrastructural scarcity of ribosomes, endoplasmic reticulum, Golgi apparatus and mitochondria, essential parts of a cell’s machinery for regeneration.
• This contradiction led the researchers to hypothesize that these ‘repair cells’ were in fact injured not regenerating cells.

Conclusion

• No evidence of inflammation or ‘repair cells’ was detected in specimens collected 40 days after the initiation of the research, further confirming the hypothesis that ‘repair cells’ are injured cells.
• The term “dysphaneroplastic”, derived from Greek, meaning “abnormal cytosol development”, was suggested to describe these cells, due to the inconsistency between the expected indications of cellular activity and their actual cytoplasmic characteristics.