Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease characterized by excessive collagen deposition and irreversible scarring. Reliable animal models are essential for elucidating IPF pathogenesis and evaluating antifibrotic therapies. However, conventional bleomycin (BLM) models generally induce only transient and moderate fibrosis. Considering the profibrotic role of eosinophils, we developed a novel IPF model using the spontaneous eosinophilic mutant Yama mice strain to achieve persistent and severe fibrosis. Male Yama and C57BL/6 mice (6 weeks old, n = 24) received eight intranasal administrations of BLM (2 mg/kg) at two-week intervals, while controls received saline. Peripheral eosinophil counts were monitored, and tissues were analyzed histologically and biochemically. Yama mice exhibited a sharp eosinophil peak after the first BLM exposure, followed by a gradual decline. Histological analysis revealed markedly enhanced fibrosis, greater collagen deposition, and higher Ashcroft scores in Yama mice than in C57BL/6 mice. Alcian blue–PAS-positive fibroblast foci, a characteristic feature of human IPF, were abundant in Yama mice. Immunohistochemistry demonstrated increased expression of eosinophil cationic protein (ECP). Moreover, mRNA expression of Th2 cytokines (IL-4, IL-5, IL-13) and profibrotic mediators (IL-6, Col1a1) was significantly higher in Yama mice. However, the pronounced fibrotic changes, TGF-β expression exhibited only a modest increase in Yama mice, suggesting that fibrosis might develop via pathways not totally dependent on conventional TGF-β signaling. This repeated BLM administration model successfully reproduces the key pathological features of severe IPF and emphasizes the pivotal contribution of eosinophils to fibrogenesis.

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This study measured serum or plasma levels of reactive oxygen metabolites (d-ROMs), biological antioxidant potential (BAP), and oxidative stress index (OSI) in dogs. The subjects were classified into four groups according to sex and gonadal status: intact males, castrated males, intact females, and spayed females, both off-therapy and during therapy. No significant differences were observed in d-ROMs, BAP, or OSI between the off-therapy and during therapy groups. Among off-therapy dogs, intact males showed significantly higher mean d-ROMs and BAP values compared with females and neutered dogs. In contrast, among during therapy dogs, no significant differences were found in d-ROMs among the groups; however, intact males had significantly higher mean BAP values than castrated males, and the OSI was significantly higher in castrated males than in intact males. These results suggest that gonadectomy in male dogs may influence the balance between oxidative and antioxidative processes through factors such as sex hormones. The findings highlight the importance of considering the effects of spaying and neutering when establishing reference values for oxidative stress markers in dogs.

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Pentosan polysulfate sodium (PPS) is a semi-synthetic sulfated polysaccharide with a heparin-like structure, known for its anticoagulant and anti-inflammatory properties. This study investigated the effect of PPS on adhesion molecules involved in neutrophil–endothelial interactions using an in vitro canine model. Canine aortic endothelial cells (CnAOEC) and neutrophils were pretreated with various concentrations of PPS and stimulated with recombinant canine tumor necrosis factor-alpha (rh-cTNFα). The mRNA expression of E-selectin, intercellular adhesion molecule-1 (ICAM-1), P-selectin, C-X-C motif chemokine receptor 2 (CXCR2), P-selectin glycoprotein ligand-1 (PSGL-1), and L-selectin was measured through real-time polymerase chain reaction (qPCR). C-X-C motif chemokine ligand 1 (CXCL1) secretion was quantified by enzyme-linked immunosorbent assay (ELISA). Lymphocyte function-associated antigen-1 (LFA-1/CD11a) expression was examined using flow cytometry. A static adhesion assay was used to evaluate the effect of PPS on neutrophil adhesion to endothelial cells. In conclusion, PPS displayed no cytotoxicity toward CnAOEC, and endothelial P-selectin expression was significantly reduced. Other adhesion molecules showed no significant differences compared with controls. CXCL1 secretion and neutrophil gene expression (CXCR2, PSGL-1, and L-selectin) varied slightly, although without statistical significance. PPS did not affect CD11a expression or neutrophil adhesion to endothelial cells. These results indicate that PPS is non-cytotoxic and may weakly modulate selectin-mediated endothelial activation without affecting integrin- or chemokine-dependent adhesion.

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Behavioral differences during and before/after dispersal were identified in two male raccoons (Procyon lotor) fitted using global positioning system (GPS) collars in Oita Prefecture, Japan. One male raccoon dispersed in a yearling spring, whereas the other dispersed in a yearling winter. The timing and direction of dispersal might reflect raccoon density in terms of differences in harvest pressure between municipalities in Oita. In both individuals, the average travel speed increased, and subsequently, the average travel distance per day rose during dispersal compared with periods before/after dispersal. During dispersal, forest use decreased, whereas artificial and agricultural land use increased in one individual, suggesting that this individual preferred anthropogenic areas for dispersal.

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