Objective To investigate the protective and cure effects of dexamethasone on bleomycin-induced pulmonary fibrosis.Methods32 rats were randomly divided into the control group (C-group, n=8), injury group (I-group, n=12) and dexamethasone group (D-group, n=12). The acute pulmonary model was established by intratracheal injection of bleomycin with rats of the I-group and D-group; while rats of the C-group injected with distilled water. After that, rats of the D-group were injected with dexamethasone sodium phosphate in intraperitoneal every day, those of the C-group and I-group were injected with saline. The animals were killed on the 3rd, 7th, 14th, and 27th days after treatment, and tests of bronchoalveolar lavage fluid (BALF), total lung collagen content and lung tissue processing were performed.ResultsPathological evidence of the I-group rats demonstrated that the alveolar compartment companied with massive inflammatory cell invasion and a number of myofibroblast proliferation became more thick. However, lung injury in the D-group rats got better than that in the I-group. Neutrophil percentage achieved peak in both I-group and D-group on the 7th day. But the neutrophil ratio in the D-group was significantly lower than that of the I-group on the 7th day ( P<0.05) and the 14th day ( P<0.01). Total lung collagen content achieved peak on the 14th day both in I-group and D-group, but that of the I-group was significantly higher than that of the C-group ( P<0.01) and the D-group was significantly lower than the I-group ( P<0.01).ConclusionDexamethasone plays a protective and cure role in lung fibrosis by efficiently inhibiting the gather and invasion of neutropils and restraining the increase of collagen secreted by proliferous fibroblasts.

BACKGROUND:More and more studies employ CD44 as a specific marker of colorectal cancer stem cells. Oct4 is a transcription factor of embryonic stem cells, and it has been discovered recently that there is a higher expression in primary colorectal carcinoma.
OBJECTIVE:To investigate the quantity, location and distribution of CD44+/Oct4+cells in primary colorectal carcinoma.
METHODS:A total y of 108 cases of human colorectal carcinoma and 18 cases of normal mucosa, 18 cases of adenoma were col ected and made into three tissue microarrays, each containing of 48 dots. The locations of CD44+/Oct4+cells were detected by double-label immunohistochemical staining and hematoxylin-eosin staining. The morphologic features of them were investigated on hematoxylin-eosin staining at the same position. 
RESULTS AND CONCLUSION:The results of double-label immunohistochemical staining demonstrated that there were no CD44+/Oct4+cells in normal intestine mucosa and a very smal amount of CD44+/Oct4+cells in adenoma, and double-positive cells could also be seen in colorectal carcinoma. The number of CD44+/Oct4+cells was rare and the cells were scattered or distributed focal y along the basement of gland basal side. The cells with scarce cytoplasm were square, and its nucleus was oval or high cylindrical, deeply stained and homogeneous. The quantity of CD44+/Oct4+cells was negatively correlated with the differentiation of colorectal cancer (r=-0.579, P<0.01), and was associated with the depth of tumor invasion (r=0.236, P<0.05). These findings indicate that CD44+/Oct4+cells may be colorectal cancer stem cells.