[Planting area estimation of Chinese Tibetan medicine Herpetospermum pedunculosum based on RS&GIS-by case study of Lengqi and Xinglong town in Luding county].

The herbs used as the material for traditional Chinese medicine are mostly planted at mountain areas where there is appropriate weather condition. Due to the complex terrain condition in mountain area, the planting at such places is always associated with a scattered pattern, which inevitably bring difficulty to the work of accurate measurement for the planting area. Advanced research about monitoring the planting area for medicine-herb under complex environmental condition is so critical and meaningful for developing the medicine-herb planting to a large scale and an industry. Therefore, this research, taking the planting of Herpetospermum pedunculosum in Luding county as an example, utilizes RS&GIS: using the image data from TM and ETM datum as the remote sensing information source, integrating GPS data from quadrat survey on the spots, and analyzing on a GIS platform, to extract the planting area of H. pedunculosum in Luding county. The results indicate that: (1) the method and technology used to estimate the planting area of H. pedunculosum are feasible and can be applied to monitoring the planting area of medicine-herb at mountain area under complex environmental conditions: (2) the planting area of H. pedunculosum in Luding county is estimated to be 857. 246 acres by the methods utilized in this research, which is closed to the value from local statistical data with an error range less than 5%; (3) in consideration of those inevitable errorrs generating from the procedures such as remote sensing data acquisition, data preprocessing, data interpretation, and so on, and the fact that the classification of remote sensing data, which must be implemented by those above procedures, was used directly to extract the herb type, the accuracy of area estimation for the herb is significantly influenced by the accuracy of classification for herb type, and the estimated area is inevitably associated with some error.

Hypo-fractionation radiotherapy normalizes tumor vasculature in non-small cell lung cancer xenografts through the p-STAT3/HIF-1 alpha signaling pathway.

BACKGROUND: Hypo-fractionation radiotherapy (HFRT) was considered to be an important treatment for non-small cell lung cancer (NSCLC), but the radiobiological effects of HFRT on NSCLC remain unclear. The aim of this study was to investigate specific biological effect of HFRT on tumor angiogenesis, compared with conventional radiotherapy (CRT). METHODS: The subcutaneous xenograft models and the dorsal skinfold window chamber (DSWC) models of nude mice bearing H460 and HCC827 NSCLC cells were irradiated with doses of 0 Gy (sham group), 22 Gy delivered into 11 fractions (CRT group) or 12 Gy delivered into 1 fraction (HFRT group). At certain time-points after irradiation, the volumes, hypoxic area, coverage rate of pericyte and micro-vessel density (MVD) of the subcutaneous xenograft models were detected, and the tumor vasculature was visualized in the DSMC model. The expressions of phosphorylated signal transducer and activator of transcription (p-STAT3), hypoxia-inducible factor 1-α (HIF-1α), CXCL12 and VEGFA were detected. RESULTS: Compared with the CRT groups, HFRT showed more-efficient tumor growth-suppression, accompanied by a HFRT-induced window-period, during which vasculature was normalized, tumor hypoxia was improved and MVD was decreased. Moreover, during the window-period, the signal levels of p-STAT3/HIF-1α pathway and the expressions of its downstream angiogenic factors (VEGFA and CXCL12) were inhibited by HFRT. CONCLUSION: Compared with CRT, HFRT induced tumor vasculature normalization by rendering the remaining vessels less tortuous and increasing pericyte coverage of tumor blood vessels, thereby ameliorating tumor hypoxia and enhancing the tumor-killing effect. Moreover, HFRT might exert the aforementioned effects through p-STAT3/HIF-1α signaling pathway.