A method using dry ashing combined with triple-phase ion-exchange chromatography was developed to enrich chlorine in the plant, which could eliminate the effect of organic impurities on the determination of chlorine isotope by thermal ionization mass spectrometry. In the procedure, the recoveries indicated that there was no loss of chlorine and no fractionation of chlorine isotopes occur. The results showed that the composition of chlorine isotope in the tissues of plants in Qinghai-Tibet Plateau area and Shandong area ranged from-1 . 79‰ to ﹢4 . 77‰ with an average of 1 . 20‰. δ37Cl values of the two plant samples in Shandong area not more than 0‰indicated that 35 Cl was enriched in the organs of the two plants andδ37Cl values in Qinghai-Tibet Plateau area more than 0‰ indicated the deficiency of 35 Cl. Chlorine isotope composition fractionated significantly in the plant samples or in different tissues of a plant. This may be caused by the differences of the medium where the plants grow, the transport of chlorine or the physiological effect in the uptake of chlorine by plants , which put forward a new insight for the further investigation of chlorine behavior in plant and the global cycling of chlorine in the biogeochemistry.

Objective To evaluate the role of gliocytes in the spinal cord in the development of inflammatory pain (IP) in rats. Methods Adult male SD rats weighing 180-220 g were used in this experiment. A catheter was implanted in the subarachnoid space according to the method described by Yang. Animals with abnormal motor function of the hindlimb after intrathecal (IT) catheter implantation were excluded. IP was induced by subcutaneous (sc) injection of complete Freund's adjuvant (CFA) 50 μl at the lateral side of the ankle joint of the right hindpaw. Sixty-five rats were randomly divided into 5 groups ( n = 13 each): group I IP control normal saline (NS) 50μl was injected sc instead of CFA; group II IP; group IE PC (IT) + IP control fluorinated citric acid (FC, a gliocyte metabolism inhibitor) 1 nmol/10μl was injected IT at 15 min before NS 50 μl sc injection; group IV NS (IT) + IP and group V FC (IT) + IP. The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured 2 d before induction of IP (T_0, baseline) .before and at 2, 4, 6, 8, 10, 12, 24 and 26 h (T_(1-9)) after sc NS or CFA injection. Five enimals in each group were killed at T_5 (8 h after sc NS/CFA injection) and the lumbar segment (L_(4,5)) was removed for determination of glial fibrillary acidic protein ( CFAP) and OX-42 expression by immuno-histochemistry. Results In group Ⅱ and Ⅳ sc CFA significantly decreased MWT and TWL. Mechanical and thermal hyperalgegia induced by sc CFA was significantly suppressed by intrathecal FC in group V . IP significantly increased GFAP and OX-42 expression in the spinal cord. Intrathecal FC significantly attenuated IP-induced up-regulation of GFAP and OX-42 expression in the spinal cord. Conclusion The activation of gliocytes in the spinal cord is involved in the development of CFA-induced hyperalgesia in rats.

Pancreatic ductal adenocarcinoma (PDAC) is among the most devastating human malignancies. The poor clinical outcome in PDAC is partly attributed to a growth-permissive tumor microenvironment. In the PDAC microenvironment, the stroma is characterized by the development of extensive fibrosis, with stromal components outnumbering pancreatic cancer cells. Each of the components within the stroma has a distinct role in conferring chemoresistance to PDAC, and intrinsic chemoresistance has further worsened this pessimistic prognosis. The nucleoside analog gemcitabine (GEM) is usually the recommended first-line chemotherapeutic agent for PDAC patients and is given alone or in combination with other agents. The mechanisms of intrinsic resistance to GEM are an active area of ongoing research. This review highlights the important role the complex structure of stroma in PDAC plays in the intrinsic resistance to GEM and discusses whether antistroma therapy improves the efficacy of GEM. The addition of antistroma therapy combined with GEM is expected to be a novel therapeutic strategy with significant survival benefits for PDAC patients.