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OBJECTIVE To evaluate the safety and efficacy of intratumoral injection of polylactic-co-glycolic acid (PLGA) microspheres containing cobra venom cytotoxin in nude mice with transplanted human hepatoma. METHODS Cytotoxic activity of cytotoxin from cobra venom was determined by using methyl thiazolyl tetrazolium method in vitro. Microspheres containing cobra venom cytotoxin were prepared with a double emulsion-solvent evaporation method. Forty BALB/c nude mice were inoculated subcutaneously in right flank with hepatoma BEL-7404 cells. Thirty-two mice whose tumor size reached about 1.0 cm in diameter, were randomly assigned into normal saline group, blank microsphers group, cytotoxin group and cytotoxin-PLGA group. Nude mice were intratumorally injected with normal saline, blank microspheres, cytotoxin or cytotoxin-PLGA microspheres respectively. Internal echo characteristics and blood flow of tumors were observed by high-frequency ultrasound every week after treatment. Twenty-six days after treatment, the tumors were removed to calculate the inhibition rate of tumor growth. The tumor, heart, liver and kidney tissues were obtained for histopathological examination. RESULTS The cytotoxin separated and purified from crude cobra venom caused intense cytotoxic effects to the BEL-7404 cells in vitro. The diameter of PLGA microspheres containing cobra venom cytotoxin was about (34.45+/-9.85)microm. Encapsulation rate was up to (78.13+/-8.92)%, and cumulative amount of cobra venom cytotoxin released from the PLGA microspheres in vitro during 30 days was up to 84.3%. After intratumoral injection, tumor volumes and weights in the cytotoxin-PLGA group were lower than those in the normal saline group, with a tumor growth inhibition rate of 52.36%. Observed under a light microscope, most tumor tissues were necrotic. No obvious morphological change could be seen on the liver, kidney and heart tissues. CONCLUSION The above findings indicate that intratumoral injection of cytotoxin-PLGA microspheres has strong antitumor effect and can obviously lessen systemic toxicity, which may provide an effective and feasible method for hepatocellular carcinoma treatment.

OBJECTIVE: To explore the efficacy and feasibility of interstitial chemotherapy using thermosensitive gel-coated ricin in hepatoma H22-bearing mice. METHODS: Ricin was purified by chromatography method. The purified ricin was identified by Western blot assay and the purity was determined by high-performance liquid chromatography. BALB/c mice were inoculated subcutaneously in right flank with hepatoma H22 cells. When the tumor size reached about 1.0 cm in diameter, 40 mice were randomly divided into untreated group, thermosensitive gel group, ricin group and thermosensitive gel-coated ricin group. Mice in each group were administered different agents by percutaneous intratumoral injection, including normal saline, thermosensitive hydrogel, ricin and thermosensitive gel-coated ricin. Fifteen days after treatment, the tumors were removed to calculate inhibition rate of tumor growth. The tumor tissues were made into pathological sections to perform histopathological examination. The ultrastructure of tumor tissue was examined by electron microscope examination as well. Blood was collected to detect the hepatic and renal functions. The caspase-3 activity of tumor tissue was determined by using zymologic method with a spectrophotometer. RESULTS: After intratumoral therapy, tumor weight in the thermosensitive gel-coated ricin group was lower than that in the untreated group, with a tumor growth inhibition rate of 71.31%. No obvious hepatic or renal toxicities were detected after thermosensitive gel-coated ricin treatment. Histopathologic observation of the tumor tissue showed massive necrosis and typical apoptosis phenomena, including chromatin margination and apoptotic body. Meanwhile, thermosensitive gel-coated ricin resulted in a significant increase in the caspase-3 activity as compared with the untreated group and the ricin group (P

To explore the feasibility of evaluating complete ischemia-reperfusion injury (IRI) of the testis by contrast-enhanced ultrasonography with microbubbles (MB) targeted to P-selectin (MBp) in rabbits.We randomly divided 30 healthy adult rabbits into five groups of equal number (control, 0.5 h IRI, 1 h IRI, 2 h IRI, and 4 h IRI), prepared phospholipid MB and MBp, and performed contrast-enhanced ultrasonography of the bilateral testes with MB or MBp at an interval of 20 min at different times after IRI. When MB or MBp disappeared completely in the healthy testis at 4 to 5 min after intravenous injection, we recorded the power of the first frame (F-P) in the IRI testes followed by immunohistochemical staining of the testis tissue.CEU with MBp achieved a significantly higher F-P than that with MB in all the IRI groups (P0.05), which was (8.34 +/- 1.20) versus (1.87 +/- 0.25) 10(-5) AU at 2 hours, but there was no significant difference between MB and MBp in the control rabbits (0 AU, P0.05). Immunohistochemistry showed a significantly time-dependent increase in the expression of P-selectin in the vascular endothelial cells of the IRI testes, but not in those of the control.Contrast-enhanced ultrasonography with MBp can be used to evaluate the inflammatory reaction of testicular ischemia-reperfusion injury.

Pancreatic cancer is one of the most aggressive malignancies, and has a poor prognosis. Despite efforts made in multiple fields, there has been little success in improving the disease-free survival rate of patients. This study was undertaken to investigate the effectiveness and feasibility of using intra-tumoral injection of ricin-loaded thermosensitive hydrogel for treatment of pancreatic cancer xenografts, attempting to develop a new treatment for human pancreatic cancer.BALB/c-(nu/nu) nude mice were inoculated subcutaneously in the right flank with the human pancreatic cancer cells, SW1990. Fourteen days after inoculation, 32 mice, bearing tumors of volume 1.5-2.0 cm3, were randomly assigned to one of four groups, and given an intra-tumoral injection of: (1) saline; (2) 23% w/w thermosensitive hydrogel alone; (3) ricin, 10 microg/kg; or (4) 10 microg/kg ricin loaded in thermosensitive hydrogel. On day 14 after administration, the tumors were excised to calculate the inhibition rate of tumor growth and perform histopathological examination. Tumor cell apoptosis was detected by flow cytometry, and RT-PCR was performed to evaluate the mRNA expression levels of Bcl2 and Bax.Intra-tumoral injection of ricin-loaded thermosensitive hydrogel resulted in remarkable control of tumor growth. The tumor became necrotic by day 14 after administration. The histological results clearly confirmed that the tumor cells were lysed. The percentage of apoptotic cells detected by flow cytometry was higher in the ricin hydrogel group than in the other groups. Semi-quantitative RT-PCR revealed that the mRNA expression level of Bcl2 was down-regulated whereas Bax was upregulated.Intra-tumoral injection of ricin-loaded thermosensitive hydrogel may provide an effective approach for interstitial chemotherapy in pancreatic cancer. Inducing apoptosis by downregulating Bcl2 expression and upregulating Bax expression may be a key molecular mechanism.

To observe the chronicity decompression effect of Astragalus Membranaceus(AM) and evaluate the effect on baroreflex sensitivity (BRS).Nineteen spontaneously hypertensive rats(SHR) were randomly divided into four groups. The AM groups were intraperitoneally administered with AM parenteral solution 0.9 mL, 1.2 mL and 1.8 mL respectively and the control group was not given AM for eight weeks. Then the change of blood pressure was observed successivly. After eight weeks, BRS were also determined. At last, the difference of blood pressure and BRS among the groups were compared.Blood pressure in the control group became higher and higher frome the third week to the eighth week, but the other SHR admistered with AM showed no changein blood pressure level. We also found that the BRS in AM group was higher than that in the control group(P0.01).AM can promote the BRS in SHR.