To investigate cellular proliferation pattern of pterygial tissue, eleven paraffin sections through two normal conjunctiva, six primary and three recurrent pterygia were studied immunohistochemically by finding epithelial cells and subepithelial fibroblasts staining patterns as defined by monoclonal antibody for proliferating cell nuclear antigen(PCNA). The results showed similar epithelial cellular proliferation patterns in normal conjunctiva, primary and recurrent pterygia. But scattered patches of fibroblasts in subepithelial connective tissue staining positive with PCNA were found only in recurrent pterygium. Our results suggest that primary pterygium is not a disorder of excess cellular proliferation, but a proliferation of fibroblasts in subepithelial connective tissue have a role in pathogenesis of recurrent pterygium.
Cell Proliferation ; Conjunctiva ; Connective Tissue ; Epithelial Cells ; Epithelium ; Fibroblasts ; Paraffin ; Proliferating Cell Nuclear Antigen ; Pterygium*

Background: Regimens for the treatment of multidrug-resistant tuberculosis (MDR-TB) have been changed from injectable-containing regimens to all-oral regimens. The economic effectiveness of new all-oral regimens compared with conventional injectable-containing regimens was scarcely evaluated. This study was conducted to compare the cost-effectiveness between all-oral longer-course regimens (the oral regimen group) and conventional injectablecontaining regimens (the control group) to treat newly diagnosed MDR-TB patients. Methods: A health economic analysis over lifetime horizon (20 years) from the perspective of the healthcare system in Korea was conducted. We developed a combined simulation model of a decision tree model (initial two years) and two Markov models (remaining 18 years, sixmonth cycle length) to calculate the incremental cost-effectiveness ratio (ICER) between the two groups. The transition probabilities and cost in each cycle were assumed based on the published data and the analysis of health big data that combined country-level claims data and TB registry in 2013–2018. Results: The oral regimen group was assumed to spend 20,778 USD more and lived 1.093 years or 1.056 quality-adjusted life year (QALY) longer than the control group. The ICER of the base case was calculated to be 19,007 USD/life year gained and 19,674 USD/QALY. The results of sensitivity analyses showed that base case results were very robust and stable, and the oral regimen was cost-effective with a 100% probability for a willingness to pay more than 21,250 USD/QALY. Conclusion This study confirmed that the new all-oral longer regimens for the treatment of MDR-TB were cost-effective in replacing conventional injectable-containing regimens.