AIM:To explore the inhibitory action of recombinant human tumor necrosis factor-related apoptosis-inducing ligand(rhTRAIL) on mouse breast cancer. METHODS:Each mouse was inoculated 0.2 mL (1?106) D2F2 cells subcutaneously in the right lower limb and they were divided into five groups randomly. The control group was infused PBS 0.2 mL,while the low-dose,medium,high groups received purified rhTRAIL 2.5 mg/kg,5.0 mg/kg,10.0 mg/kg,respectively,the positive group was administered cyclophosphamide 30.0 mg/kg. Every group was operated by peritoneal injection once a day for fifteen days. The mice were weighed every day. The growth state was viewed and the size of the tumor was measured every 3 d to calculate the tumor volume and tumor suppression rate. All mice were killed after 15 d. The pathologic changes of the tumor were observed under light-microscopy and electronic microscopy. The cell cycle and apoptosis index of D2F2 cells were analyzed by flow cytometry. RESULTS:The body weight and tumor volume in low-dose,medium,high groups were lower than those in control group and the restriction effect was more significant than that in the control group (P

Tetraselmis subcordiformis, a marine green alga, can produce hydrogen by photobiologically hydrolyzing seawater with hydrogenase. In this study, the preliminary purification of the enzyme was explored by ammonium sulfate precipitation, and the impact of sodium dithionite, beta-mercaptoethanol and glycerol on the enzyme stability during the process was investigated. The experimental results illustrated that sodium dithionite provided significant protection on the hydrogenase by depleting oxygen, while glycerol, a protectant against the structure instability of the enzyme, also presented protection. Crude enzyme with specific activity of 0.557 U/mg protein was extracted using 60%-70% saturated ammonium sulfate solution supplemented with 200 mmol/L sodium dithionite and 5% glycerol, and the hydrogenase recovery yield was about 30%.
Ammonium Sulfate ; chemistry ; Chemical Precipitation ; Chlorophyta ; enzymology ; Enzyme Stability ; Hydrogen ; metabolism ; Hydrogenase ; isolation & purification ; metabolism ; Seawater

Sponges (Porifera) are the oldest living metazoan in the world, among which most of them (Demospongia) can produce silicic skeleton from orthosilicic acid in the seawater under the natural enVironmental conditions. These biosilicic materials exhibit good mechanical and optical properties as well as good biocompatibility. During the biosilicification process of sponges, a protein, named as silicatein, plays an important role and has attracted great attention from biologist, chemists and material scientists. This mini review highlights the discovery of silicateins and its function as both an enzymatic catalyst and an organic template for biosilicification. The studies since 1999 were briefly introduced on the application of silicatein as a biocatalyst and template for synthesis of silica-based and other inorganic materials. It is expected to stimulate the interests in the related researches in China.
Animals ; Biocatalysis ; Biocompatible Materials ; Cathepsins ; chemistry ; Porifera ; enzymology ; Silicon Dioxide ; metabolism

Objective:To evaluate the role of 1, 4, 5-inositol triphosphate receptor (IP3R) in necroptosis of hippocampal neurons induced by sevoflurane anesthesia in aged rats.Methods:Sixty healthy male Sprague-Dawley rats, aged 18 months, weighing 500-600 g, were divided into 3 groups ( n=20 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S) and sevoflurane anesthesia + IP3R antagonist group (group S+ I). S and S+ I groups inhaled 2% sevoflurane for 5 h. In group S+ I, IP3 receptor antagonist 2-APB 3 mg/kg was intraperitoneally injected at 10 min before sevoflurane inhalation, and the equal volume of dimethyl sulfoxide was intraperitoneally injected in group C and group S. Morris water maze test was used to test the cognitive function on the day after the end of sevoflurane anesthesia.Then the animals were sacrificed and the brain tissues were obtained for microscopic examination of the pathological changes after HE staining and Nissl staining (with a light microscope) and for determination of the free calcium concentration ([Ca 2+ ] i) and rate of necroptosis of hippocampal neurons (by flow cytometry) and expression of IP3R, receptor-interacting protein kinase-1 (RIPK1), receptor-interacting protein kinase-3 (RIPK3) and phosphorylated mixed lineage kinase domain-like protein (p-MLKL) (by Western blot). Results:Compared with group C, the escape latency was significantly prolonged, the times of crossing the platform were reduced, the time of staying at the target quadrant was shortened, the [Ca 2+ ] i and necroptosis rate of hippocampal neurons were increased, and the expression of IP3R, RIPK1, RIPK3 and p-MLKL in hippocampal neurons was up-regulated in group S and group S+ I ( P<0.05). Compared with group S, the escape latency was significantly shortened, the times of crossing the platform were increased, the time of staying at the target quadrant was prolonged, the [Ca 2+ ] i and necroptosis rate of hippocampal neurons were decreased, and the expression of IP3R, RIPK1, RIPK3 and p-MLKL in hippocampal neurons was down-regulated in group S+ I ( P<0.05). Conclusions:The mechanism by which sevoflurane induces cognitive dysfunction may be related to the imbalance of calcium homeostasis caused by activation of IP3R and thus inducing programmed necrosis in aged rats.

Objective:To evaluate the effect of esketamine on hippocampal neuronal necroptosis in aged rats with postoperative cognitive dysfunction.Methods:One hundred and twenty SPF-grade healthy male Sprague-Dawley rats, aged 22 months, weighing 550-600 g, were divided into 4 groups ( n=30 each) using a random number table method: control group (group C), postoperative cognitive dysfunction group (group P), postoperative cognitive dysfunction+ esketamine group (group PE), and esketamine group (group CE). Rats received exploratory laparotomy under sevoflurane anesthesia, and esketamine 10 mg/kg and the equal volume of 0.9% sodium chloride were intraperitoneally injected at the end of surgery once a day for 6 consecutive days in group P and group PE, respectively. Rats received no anesthesia and surgery, and esketamine 10 mg/kg and the equal volume of 0.9% sodium chloride were intraperitoneally injected at the end of surgery once a day for 6 consecutive days in group CE and group C, respectively. Morris water maze test was performed at 7th day after surgery. The escape latency, times of crossing the original platform and time spent in the original platform quadrant were recorded. The rats were sacrificed at the end of Morris water maze test, and the hippocampal tissues were collected for determination of the rate of necroptosis and cytosolic Ca 2+ concentrations (by flow cytometry) and expression of mixed lineage kinase domain-like protein (MLKL), phosphorylated MLKL (p-MLKL), receptor-interacting protein kinase-3 (RIPK3), phosphorylated RIPK3 (p-RIPK3), receptor-interacting protein kinase-1 (RIPK1) and phosphorylated RIPK1 (p-RIPK1) (by Western blot). Results:Compared with group C, the escape latency was significantly prolonged, the times of crossing the original platform were decreased, the time spent in the original platform quadrant was shortened, the necroptosis rate of hippocampal neurons and cytosolic Ca 2+ concentrations were increased, and the expression of MLKL, p-MLKL, RIPK3, p-RIPK3, RIPK1 and p-RIPK1 was up-regulated in group P and group PE ( P<0.05). Compared with group P, the escape latency was significantly shortened, the times of crossing the original platform were increased, the time spent in the original platform quadrant was prolonged, the necroptosis rate of hippocampal neurons and cytosolic Ca 2+ concentrations were decreased, and the expression of MLKL, p-MLKL, RIPK3, p-RIPK3, RIPK1 and p-RIPK1 was down-regulated in group PE ( P<0.05). Conclusions:The mechanism by which esketamine attenuates postoperative cognitive dysfunction may be related to inhibition of necroptosis in hippocampal neurons of aged rats.

Pulmonary fibrosis (PF) is a chronic, progressive, fatal interstitial lung disease with limited available therapeutic strategies. We recently reported that the protein kinase glycogen synthase kinase-3