custom rutile type titanium dioxide manufacturer_custom rutile type titanium dioxide manufacturer

In contrast to kaolin, bentonite had a very strong effect on the rat lung on day 3. Even compared to quartz DQ12 positive control, AM and PMN counts were 1.15- and 3.1-fold higher, respectively. In addition, the increases in total protein and fibronectin in BALF outscored the values of quartz DQ12 by far (Figure 4), indicating lung cell damage and/or epithelial leakage. Lung biopsy revealed numerous opaque and even petechia-like sites at the outer lung surface (Figure S2) on day 3. Interestingly, these macroscopic signs of damage and also most other inflammatory markers had decayed down to the control level on day 21, except for the still increased AM counts, which were confirmed by histology on days 3 and 21 (Figure S1). In contrast to quartz DQ12-treated lungs, alveolar septae in bentonite-laden lungs appeared hypertrophic with beginning hyperplasia. Numerous pSP-C-positive type-2 cells were found close to assemblies of CD68 positive AM (Figure 6). Interestingly, the CD68 staining intensity of many alveolar macrophages was low in bentonite-laden lungs. Weakly CD68-positive cells with bubble-like inclusions were also found within alveolar septae and appeared equivalent to similar formations seen in HE-stained tissue (Figure S1, Figure 6). By means of polarization microscopy, but hardly by DFM (Figure S1), birefringent particles were seen in alveolar macrophages. Unlike quartz DQ12 or kaolin treatment, bentonite particles also appeared within alveolar septae (Figure 5). Therefore, a staining for immunoreactive nitrotyrosin was carried out, showing immunopositive areas in alveolar septae not seen in controls (Figure S4). Overall, bentonite elicited a very strong, though transient, inflammation of the lung along with beginning structural changes of the lung epithelium.