Choline improves lipopolysaccharide-induced central nervous system inflammatory response and cognitive dysfunction in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the effect of choline in ameliorating lipopolysaccharide (LPS)-induced central nervous system inflammation and cognitive deficits in mice and explore the underlying mechanism.</p><p><b>METHODS</b>Seventy-two mice were randomized into saline control group, LPS group, choline intervention group and choline control group. In the latter two groups, the mice received pretreatment with intraperitoneal injections of choline (40 mg/kg, 3 times daily for 3 consecutive days) prior to microinjection of LPS into the lateral cerebral ventricle to induce central nervous system inflammation; in saline and LPS groups, the mice were pretreated with saline in the same manner before intraventicular injection of artificial cerebrospinal fluid. Choline treatment was administered in the mice till the end of the experiment. The locomotor activity and spatial learning and memory capacity of the mice were examined. The expressions of Iba1 protein and proinflammatory cytokines (TNF-α and IL-β) I the hippocampal dentate gyrus, and the expressions of α 7nAchR, p38 MAPK and phosphorylated p38 MAPK in the hippocampus of the mice were detected.</p><p><b>RESULTS</b>Water maze test showed that compared with the saline control group, the mice in LPS group exhibited significantly reduced platform crossings (P<0.05), which was significantly increased by choline pretreatment (P<0.05). The mice pretreated with LPS expressed obviously increased levels of IBA-1 protein, TNF-α, and IL-1β in the hippocampus (P<0.01), and choline pretreatment significantly lowered the expressions of IBA-1 protein and IL-1β (P<0.05). The phosphorylation level of p38 MAPK increased significantly after LPS pretreatment (P<0.05), and was reduced by choline pretreatment (P<0.05); α 7nAchR expression increased significantly in choline intervention group as compared with that in the other 3 groups (P<0.05).</p><p><b>CONCLUSION</b>Choline can probably antagonize LPS-induced hippocampal p38 MAPK phosphorylation in mice via the α 7nAchR signaling pathway to protective against LPS-induced neuroinflammation and cognitive impairment in mice.</p>

Protective effect of dexmedetomidine against glutamate-induced cytotoxicity in PC12 cells and its mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the protective effects of dexmedetomidine (Dex) against glutamate-induced cytotoxicity in PC12 cells and its mechanism.</p><p><b>METHODS</b>PC12 cells were treated with varying concentrations of dexmedetomidine 1 h before exposure to a high concentration of glutamate. The cell viability was measured by MTT assay, and LDH release, MDA content and SOD activity were measured. The level of ROS was tested by DCFH-DA staining and flow cytometry. The level of intracellular Cawas detected by Fluo-8 staining and flow cytometry, and the mitochondrial membrane potential (MMP) was determined with JC-1 staining and flow cytometry.</p><p><b>RESULTS</b>Within the concentration range of 0.01 to 100 µmol/L, Dex dose-dependently protected PC12 cells against glutamate-induced cytotoxicity. Treatment with 100 µmol/L Dex significantly increased the cell viability to (86.6∓2.2)% of that of the control cells (P<0.01) and decreased LDH release to 1.4∓0.1 folds of the control level (P<0.01). In PC12 cells exposed to glutamate, Dex pretreatment significantly reduced MDA content (P<0.01), enhanced SOD activity (P<0.01), inhibited ROS overproduction (P<0.01), reduced intracellular Calevel (P<0.01) and maintained a stable MMP (P<0.01).</p><p><b>CONCLUSION</b>Dexmedetomidine can protect PC12 cells against glutamate-induced injury possibly in relation with its anti-oxidative activity, inhibitory effect on intracellular calcium overload and protective effect of the mitochondria.</p>

Synergistic analgesic effect of choline and parecoxib sodium in mice and the mechanism / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the synergistic analgesic effect of choline and parecoxib sodium and study its mechanism.</p><p><b>METHODS</b>In male Kunming mice with acetic acid-induced writhing, the EDof choline and parecoxib sodium (administered via the tail vein at 2 h and 30 min before modeling, respectively) and their combined use were determined. In saline (control) group, EDcholine (C) group, EDparecoxib sodium (P) group, and 1/2EDcholine and parecoxib sodium (1/2[C+P]) group, blood samples were collected from the eyeball 10 min after intraperitoneal administration of acetic acid to detect the levels of IL-1, TNF-α, PGE2, NF-κB, and I-κB levels using ELISA kits.</p><p><b>RESULTS</b>In the acetic acid-induced writhing model, the EDof choline and parecoxib sodium was 8.64 and 6.33 mg/kg, and when combined, their ED50 was 2.13 and 1.56 mg/kg, respectively. The isobolograms of parecoxib sodium and choline showed that the measured EDof the two drugs combined was below the theoretical EDvalue (P<0.05) with a combination index (CI) of <0.9. Compared with the control group, C group, P group, and 1/2 (C+P) group all showed significantly lowered IL-1 and TNF-α levels (P<0.05), especially in 1/2 (C+P) group (P<0.05). PGE2 level was significantly lower in P group and 1/2 (C+P) group compared with the control group (P<0.05). NF-κB and I-κB levels were significantly lowered in C, P, and 1/2 (C+P) groups (P<0.05), and the reduction was the most obvious in 1/2 (C+P) group (P<0.05).</p><p><b>CONCLUSION</b>Choline and parecoxib sodium has a synergistic analgesic effect, and their interactions may involve the in vivo expression of NF-κB.</p>

Oncogenic signaling mechanisms in imatinib-resistant gastrointestinal stromal tumor / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To characterize oncogenic KIT signaling mechanisms in gastrointestinal stromal tumor(GIST), and to determine which signaling pathway might be of potential relevance to imatinib acquired resistance.</p><p><b>METHODS</b>The mutations of KIT and PDGFRa gene were evaluated and KIT downstream signaling profiles were evaluated in 8 specimen from 5 GIST patients who were evaluated treated between 2003 and 2008 in our hospital. Biochemical inhibition of the expression of related proteins in Ras/Raf/MAPK and PI3-K/AKT pathways, such as KIT, mitogen-activated protein kinase(MAPK),mammalian target of rapamycin(MTOR), AKT, Proliferating cell nuclear antigen (PCNA) and BCL-2, were determined by Western blotting for protein activation.</p><p><b>RESULTS</b>Three cases who showed response to imatinib carried primary mutations in KIT gene, with 2 cases possessing mutation in exon 11, 1 case in exon 13. One case with imatinib-resistance developed KIT secondary mutation, but all the cases had no PDGFRa mutation. p-KIT and p-AKT expressions were higher in the samples of imatinib-resistant GIST than those of imatinib-responsive GIST. Total KIT, MAPK, p-MAPK, p-MTOR expressions were strong and comparable in all varied GISTs, which had no significant difference between imatinib-resistant and imatinib-responsive samples. PCNA and BCL-2 expression varied in samples of different therapy cycles and different location.</p><p><b>CONCLUSIONS</b>Ras/Raf/MAPK and PI3-K/AKT/MTOR pathways are essential to GIST pathogenesis. The KIT secondary mutation and PI3-K/AKT/MTOR pathway are particularly relevant for therapeutic targeting in imatinib-resistant GIST.</p>

Surgical treatment for patients with advanced gastrointestinal stromal tumor after targeted therapy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the role of surgery and its long-term outcome in patients with advanced gastrointestinal stromal tumor(GIST) treated with imatinib preoperatively.</p><p><b>METHODS</b>Thirteen patients receiving imatinib therapy preoperatively, were retrospectively assessed for completeness of surgical resection and for disease-free and overall survival after resection.</p><p><b>RESULTS</b>Thirteen patients, including 3 patients with locally advanced primary GIST and 10 patients with recurrent or metastatic GIST, underwent surgery after preoperative treatment with imatinib. Complete resections were accomplished in 4 of the 5 responsive disease(RD) patients, and in 1 of the 8 progression disease(PD) patients (38.5%). The progression-free survival(PFS) time for patients with RD and PD were 24.8 months and 2.8 months respectively. The difference of PFS between patients with RD and those with PD was significant(P<0.01). Median overall survival(OS) was not reached in both patients with RD and PD. The difference of OS between patients with RD and those with PD was not significant(P>0.05).</p><p><b>CONCLUSION</b>Surgical intervention following imatinib is feasible and can be considered for patients with advanced GIST responsive to imatinib.</p>

Status and clinical analysis of c-kit and PDGFRA mutations in the gastrointestinal stromal tumors / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the status of c-kit and PDGFRA mutations in the gastrointestinal stromal tumors (GIST) and explore the relationship between the mutations and the clinical features.</p><p><b>METHODS</b>One hundred and forty-one cases were evaluated for the presence of c-kit and PDGFRA mutations. Exon 9,11,13, 17 of c-kit and exon 12, 18 of PDGFRA were analyzed by PCR amplification and direct sequencing. The relations of clinical features and mutational status were analyzed with statistical tools in this study.</p><p><b>RESULTS</b>Among the 141 GISTs, c-kit mutations were identified in 76.6% (108/141): 70.2% (99/141) involving exon 11, 5.7% (8/141) involving exon 9, 0.7% (1/141) involving exon 13 and no mutation detected in exon 17. The gene mutations were mostly heterogeneous. The c-kit exon 11 mutational format included deletion (65.7%), point mutation (24.2%) and insert duplications(10.1%).The mutations clustered in the classic "hot spot" at the 5' end of the exon mostly heterogeneous and the second "hot spot" were internal tandem duplications (ITD) at the 3' end of the exon. PDGFRA mutations were totally identified in 12.1%(4/33) of no-c-kit-mutation GISTs and 40%(4/10) of CD117-negative GISTs: all involving exon 18 with the mutations D842V. With the analysis between clinical features and mutation status, the significant difference of gene mutation rate in the different primary tumor organs (chi(2)=7.229, P=0.027, chi(2)=7.000,P=0.03) and no significant differences between the groups of age,gender,tumor size,mitotic rate,grade of malignant potential were found.</p><p><b>CONCLUSION</b>Most GISTs have the c-kit or PDGFRA gene mutation. There are significant difference between mutation and primary tumor organ.</p>