[Ecological adaptability of leaf epidermis of erosion-resistant plants in hilly-gully area of Loess Plateau, Northwest China].

By the temporary slide method of leaf epidermis, an observation was made on the morphological characteristics of the leaf epidermis of six erosion-resistant plant species in different soil erosion environments (gully, inter-gully, and inter-gully artificial Robinia pseudoacacia forest land) in hilly-gully area of Loess Plateau. Compared with those in the gully, the stomata aperture, stomata density, stomata index, stomata apparatus length/width plasticity, stomata apparatus area plasticity, epidermal hair density, and epidermal cell density of the leaf upper and lower epidermis of the plants in the inter-gully were 93.8% and 90.4%, 66.8% and 76.6%, 17.9% and 9.8%, 36.4% and 47.1%, 42.3% and 43.9%, 199.4% and 98.2%, and 46.5% and 50.1% higher, respectively; while in the inter-gully artificial R. pseudoacacia forest land, the same morphological indices of the leaf upper and lower epidermis of the plants were 66.7% and 106.7%, 20.5% and 45.8%, 11.9% and 11.9%, 37.9% and 41.3%, 19.8% and 21.2%, 113.1% and 52.2%, and 10.8% and 28.1% higher than those in the gully, respectively. The epidermal hair length and epidermal cell area of the leaf upper and lower epidermis of the plants in the inter-gully were 58.8% and 29.7%, and 40.3% and 37.0% lower than those in the gully, and the same morphological indices of the leaf upper and lower epidermis of the plants in the intergully artificial R. pseudoacacia forest land were respectively 25.0% and 23.6%, and 22.2% and 19.2% lower than those in the gully, respectively. The results suggested that the erosion-resistant plants in the study area were able to adapt to various soil erosion environments by increasing their leaf stomata aperture, stomata density, stomata index, stomata apparatus length/width plasticity, stomata apparatus area plasticity, epidermal hair density, and epidermal cell density, and by reducing their epidermal hair length and epidermal cell area.

[The changes in secretory function of pulmonary intravascular macrophages after challenge of lipopolysaccharide].

OBJECTIVE: To investigate the role of pulmonary intravascular macrophages (PIMs) in the pathogenesis of acute lung injury (ALI) due to infection. METHODS: Porcine pulmonary blood vessels were flushed by modified Morton method, and PIMs were isolated and cultured. The adhered PIMs were collected with adhesion method and incubated in RPMI 1640 medium. They were challenged with lipopolysaccharide (LPS, 10 mg/L). The activity of interleukin-1ß (IL-1ß), and contents of IL 6 and IL 8 in the culture supernatant were measured by method of thymocyte proliferation and enzyme linked immunoadsorbent assay (ELISA). RESULTS: The released contents of IL-1ß, IL-6 and IL-8 from PIMs were increased significantly compared with those before LPS challenge , and they peaked at 2 hours [IL-1ß activity: (10 400 ± 2 389) scintillant count/min], 4 hours [IL-6 content: (0.80 ± 0.36) µg/L], and 6 hours [IL-8 content: (4.94 ± 1.19) µg/L ] after LPS challenge , and the differences were significant compared with hose before LPS challenge [IL-1ß activity: (213 ± 85) scintillant count/min, IL-6 content: (0.27 ± 0.12) µg/L, IL-8 content: (1.84 ± 0.53) µg/L, all P <0.01]. CONCLUSION: Among the cytokines released from PIMs after LPS challenge , the increase in IL-1ß occurred earlier in comparison with that of IL-6 and IL-8, suggesting that the former might play an important role at the early stage of ALI; on the other hand, though the increase in IL-6 and IL-8 contents occurred later than that of IL- 1ß but it lasted for a longer duration, suggesting that they might be associated with the advancement of ALI. The Results also suggested that interaction of these cytokines played a more important role in the pathogenesis of ALI.

[Changes in inflammatory cytokines released by pulmonary intravascular macrophages after stimulation with lipopolysaccharide].

OBJECTIVE: To investigate the roles of pulmonary intravascular macrophages (PIMs) in the pathogenesis of infective acute lung injury (ALI). METHODS: Porcine pulmonary blood vessels were flushed by modified Morton's method, PIMs were isolated with adhesion method and incubated in RPMI 1640 medium. They were stimulated with lipopolysaccharide (LPS, 10 mg/L). The contents of interleukin-6 (IL-6), IL-8 and tumor necrosis factor-alpha (TNF-alpha) in the culture supernatants were respectively measured by enzyme linked immunoadsorbent assay (EILSA). RESULTS: The release of TNF-alpha, IL-6 and IL-8 by PIMs was increased significantly as compared with the levels before stimulation by LPS, peaking at 1, 4, and 6 hours after LPS stimulation, respectively. The differences were significant (all P<0.01). CONCLUSION: Among the cytokines released by PIMs after LPS challenge, the increase in TNF-alpha content occurs earlier in comparison with that of IL-6 and IL-8, suggesting that the former may play an important role at the early stage of ALI. On the other hand, the increase in IL-6 and IL-8 contents is later than that of TNF-alpha and lasts for a longer time, suggesting that they may be associated with the development of ALI. The results also suggest that interaction of these cytokines is more important in the pathogenesis of ALI.