Preventive effect of propylthiouracil administration upon pulmonary fibrosis development in HOCl-induced murine model of systemic sclerosis. Representative Masson's trichrome-stained section of lung examined by light microscopy: (A) Normal histology of a representative lung tissue from Sham mouse; (B) Representative lung section from HOCl mouse; (C) Representative lung section from HOCl + PTU mouse (Original magnification, ×10.); (D) Semiquantitative analysis of lung tissue graded by using the Ashcroft score, as described in Methods. The degree of pulmonary fibrosis was evaluated in Masson trichrome-stained sections by using the Ashcroft score (the grade of lung fibrosis was scored on a scale of 0 to 8 by using the following criteria: grade 0, normal lung; grade 1 to 2, minimal fibrous thickening of alveolar or bronchiolar wall; grade 3 to 4, moderate thickening of walls without obvious damage to lung architecture; grade 5 to 6, increased fibrosis with definite damage to lung structure; and grade 7 to 8, severe distortion of structure and large fibrous areas. Values are expressed as the mean and SD. *P < 0.001 versus Sham; #P < 0.001 versus HOCl. HOCl group (n = 10), HOCl + PTU group (n = 10), Sham (n = 5).
Bagnato et al. Arthritis Research & Therapy 2013 15:R120 doi:10.1186/ar4300