Search

Fluorescent imaging of β-amyloid (Aβ) is one of the most promising methods for Alzheimer's disease diagnosis. Several fluorescent probes have been reported to detect Aβ both in vitro and in vivo. However, highly sensitive and highly selective probes with low background signals are still greatly needed. Herein, we rationally designed and synthesized a PIET quenched near-infrared probe QAD-1 to detect Aβ. This probe contains BODIPY as fluorophore and tetrahydroquinoxaline as the quenching group. QAD-1 exhibited significant fluorescent switch-on after binding to soluble and insoluble Aβ species, and the probe had the benefit of low background signal to stain Aβ plaques without the need of wash-out procedures in vitro, which was specially found by the fluorescence off-on probe. QAD-1 could identify the overproduced Aβ in transgenic (APPSWE/PSEN 1dE9) AD mice as early as 6 months old in vivo, which indicated that QAD-1 may be a potential probe for monitoring Aβ species at an early stage of AD.

(2'R)-2',3'-Dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol (DHMB) is a natural compound extracted from Morus notabilis. It was found that DHMB acts as a competitive inhibitor against mushroom tyrosinase with a Ki value of 14.77 μM. Docking results further indicated that it could form strong interactions with one copper ion with a distance of 2.7 Å, suggesting the mechanism of inhibition might be due to chelating copper ions in the active site. Furthermore, melanin production in B16-F10 murine melanoma cells was significantly inhibited by DHMB in a concentration-dependent manner without cytotoxicity. The results of western blotting also showed that DHMB decreased 3-isobuty-1-methxlzanthine-induced mature tyrosinase expression. Taken together, these findings indicated that DHMB may be a new promising pigmentation-altering agent for agriculture, cosmetic, and therapeutic applications.

To study the antiangiogenetic and tumor inhibitory effects of endostatin (Es) by intratumoral versus intravenous administration combined with adriamycin (Adm) for treatment of transplanted tumor in mice.Forty mice were subjected to subcutaneous implantation of H22 cells and randomly divided into 4 groups by the body weight when the tumor diameter reached 1 cm, namely the control group (with intratumoral and intravenous injection of normal saline), Es intratumoral group (with intratumoral injection Es and intraperitoneal Adm injection), Es vein group (with intravenous Es injection and intraperitoneal Adm injection), and Adm group (with intratumoral saline injection and intraperitoneal Adm injection). The tumor volumes and tumor inhibition rates were calculated, and the expression of vascular endothelial growth factor (VEGF) and the microvessel density (MVD) of the tumors were examined, with the survival time of the mice also observed.The tumor volume was smaller in Es intratumoral group than in the other groups (P0.05). The expression of VEGF and M VD in Es intratumoral group was significantly decreased as compared with that in the other groups (P0.05). The survival time was significantly longer in Es intratumoral group and Es vein group than in the other groups (P0.05), but showed no significant difference between Es intratumoral group and Es vein group (P0.05).In combination with Adm regimen, Es given intratumoral injection produces better effect than intravenous Es injection against angiogenesis and tumor growth, no significant difference can be found in the survival time between them.

To study the effect of of percutaneous para-toluenesulfonamide (PTS) injection on transplanted hepatocarcinoma in nude mice.Sixty nude mice with subcutaneous transplanted hepatocarcinoma were randomized into 6 groups, namely PTS, chemotherapy, radiotherapy, PTS+chemotherapy, PTS+radiotherapy and control groups. PTS were injected into the tumor in the nude mouse models as indicated, and the tumor growth rate and survival time of the mice were recorded.All the treatments resulted in effective arrest of the tumor growth, but the effects of PTS+chemotherapy and PTS+radiotherapy were more obvious. No significant difference in the survival time of the mice were noted between the groups.PTS+chemotherapy and PTS+radiotherapy are safe and reliable, and produces better effects than either radiotherapy or chemotherapy alone.

To observe the effects of three commonly used local ablation methods in the treatment of transplanted hepatocellular carcinoma in mice to provide experimental evidence for treating hepatocellular carcinoma that defies surgical removal.Mouse models of hepatocellular carcinoma were established by means of subcutaneous transplantation, and treatment results of the three ablation methods, namely percutaneous ethanol injection therapy (PEIT), percutaneous acetic acid injection therapy (PAIT) and percutaneous local cryosurgery therapy (PLCT), were compared.The tumor inhibition rates of PLCT, PAIT and PEIT were 99.2%, 85.3%, and 72.8%, respectively. The rates for complete necrosis of the tumors were 100% (5/5), 60% (3/5), and 40% (2/5), with the survival time of 88.11+/-5.67, 86.67+/-7.26, and 72.89+/-12.86 days respectively.All of the three local ablation methods can inhibit the tumor growth to various degrees and prolong the survival time of the tumor-bearing mice. PLCT may yield relatively better result than the other two methods.