[Pathological change in the brain of mice infected with Angiostrongylus cantonensis].

OBJECTIVE: To observe the pathological change in the brain of Angiostrongylus cantonensis-infected mouse. METHODS: Forty-eight mice were orally infected each with 40 third stage larvae of A. cantonensis, 3 mice were sacrificed at 7, 10, 13, 16, 19, 22, 25, 28 days postinfection respectively for worm recovery, and another 3 mice were for observing the histopathological change in tissue sections of the brain. RESULTS: Ten days postinfection, worms were found in the brain of the infected mice with a mean worm number of (7.0+/-1.7) per mouse. The highest number of worms was found at 16 days postinfection, with a mean of (23.7+/-4.9) per mouse. Notable symptoms of nervous system were seen on 15 days postinfection. Most mice died around 22 days postinfection. Histological examination revealed mechanical damages. Cavities and inflammation were observed in the brain parenchyma. Worms were seen in the subarachnoid space. Meningitis-like signs started at 13 days and aggravated then. CONCLUSIONS: Infection of A. cantonensis causes pathological change in mouse brain and the process is aggravating with postinfection time.

[Effect of down-regulation of survivin gene on apoptosis and cisplatin resistance in cisplatin resistant human lung adenocarcinoma A549/CDDP cells].

OBJECTIVE: To investigate the effects of survivin antisense oligodeoxynucleoties (ASODN) transfection mediated by cytofectin on apoptosis and cisplatin resistance in cisplatin resistant human lung adenocarcinoma A549/CDDP cells in vitro. METHODS: A549/CDDP cells were cultured routinely in RPMI-1640 medium. Survivin ASODN mediated by cytofectin was transfected into the A549/CDDP cells. Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry SABC assays were performed to determine the regulation of survivin expression by ASODN. The influence of ASODN transfection on apoptosis was determined by fluoroscence microscopy and Hoechst staining, agarose gel electrophoresis, flow cytometry and caspase-3 colorimetric assay. MTT assay was performed to detect the cell viability, half-maximum inhibitory concentration (IC50) and cisplatin resistance index (RI) were thereby calculated. RESULTS: Transfected by survivin ASODN for 48 h, down-regulation of survivin expression was measured, of which mRNA and protein expression was significantly down-regulated to 41.56% and 0.864 +/- 0.045, respectively (P < 0.05). Transfection with survivin ASODN caused typical apoptotic changes, including characteristic chromatin condensation, nuclear shrinkage, nuclear cleavage and the cells grew more regularly, and some cells were floating. Typical DNA ladder pattern was observed by agarose gel electrophoresis. Furthermore, apoptotic index and caspase-3 activity was enhanced to 34.03% and 1.1298 +/- 0.2502, respectively (P < 0.05). It was significantly different as compared with the control group. While combination with ASODN and 10 micromol/L cisplatin caused far more distinctive apoptotic alterations, of which AI and caspase-3 activity reached to 65.85% and 1.6805 +/- 0.2758, respectively (P < 0.05), and even compared with the single ASODN group, the difference was still significant (P < 0.05). Transfected with survivin ASODN only or with combination of cisplatin for 48 h, the inhibitory rate of cell growth was enhanced to 59.3% and 83.7% (P < 0.05), respectively, while inversely, the cell viability reduced to a lowest value. The half-maximum inhibitory concentration of cisplatin was reduced from 225.03 +/- 10.59 micromol/L to 158.84 +/- 4.26 micromol/L, and the resistant index was conversely reduced from 11.9 to 8.39. Non-sense oligodeoxynucleotides (NSODN) and liposome had no effect on the cells growth (P > 0.05). CONCLUSION: Transfection with survivin ASODN can to a great extent reverse the cisplatin resistance in human cisplatin resistant lung adenocarcinoma cells A549/CDDP in vitro, and can thereby significantly inhibit the growth of the cells. The mechanism of reversal of resistance to cisplatin by this transfection can be associated with specific down-regulation of survivin expression, which decreases the threshold of apoptosis, induces more pronounced apoptosis,and reverses the resistance to apoptosis induced by cisplatin in A549/CDDP cells in vitro.

[Experimental study of antisense oligodeoxynucleotide targeting survivin gene for cisplatin resistant human lung adeno-carcinoma xenograft in nude mice].

OBJECTIVE: To explore the feasibility of antisense oligodeoxynucleotide (ASODN) targeting survivin gene for cisplatin resistant human lung adeno-carcinoma xenograft in nude mice. METHODS: Cisplatin resistant cell lines A549/CDDP were cultured routinely with RPMI1640 medium. A549/CDDP cells were subcutaneously implanted in nude mice to establish cisplatin resistant xenograft animal models. After survivin ASODN mediated by cytofectin was directly injected into xenograft in 5 places. The volumes and weight of tumor mass were detected, respectively, and then tumor growth inhibitory rate and tumor growth index were calculated. Reverse transcription-polymerase chain reaction (RT-PCR) and immunochemohistology assay were performed to detect the expression level of survivin mRNA and protein. RESULTS: In mice treated with single ASODN, the tumor growth inhibitory rate and tumor growth index was 35.4% and 4.23+/-0.4456. The difference of the tumor growth inhibitory rate and tumor growth index between blank control group and ASODN group was significant (P<0.05). While combined ASODN with cisplatin,the anticancer efficacy was far more significant and the tumor growth inhibitory rate was enhanced to 63.7%. The tumor growth index, however, reduced to 1.700+/-0.436, which was obviously significant,compared with the cisplatin group and other controls (P<0.05). The anticancer efficacy was even more obvious than that of ASODN group (P<0.05). Significant down-regulation of survivin mRNA and protein level expression in tumor tissues of ASODN group and ASODN and cisplatin group was detected by RT-PCR and immunochemohistology assay, respectively (P<0.05). CONCLUSION: Survivin ASODN mediated by cytofectin can inhibit the cisplatin resistant tumor growth by direct intra-tumoral injection. The anticancer efficacy may be associated with the down regulation of survivin expression. ASODN targeting survivin gene can be a supportive therapy to cisplatin resistant lung cancer, while the clinical effective values need further exploration.

[Effect of Xingding Injection on expression of heat shock protein 72 in vascular endothelial cells].

OBJECTIVE: To study the effect of Xingding Injection on the expression of heat shock protein 72 (HSP 72) in vascular endothelial cells after ultraviolet radiation. METHODS: Porcine aortic endothelial cells were cultured for 72 hours in culture mediums with different concentrations (0.1, 0.5, 1.0, 5.0, 10 mg/ml) of Xingding Injection. Ultraviolet radiation was administered to the cultured cells for 30 minutes. Western-blot assay was used to measure the expression of HSP 72 in the vascular endothelial cells. RESULTS: There was no expression of HSP 72 in the cultured vascular endothelial cells without ultraviolet radiation, but there was some expression of HSP 72 after ultraviolet radiation. Xingding Injection of different concentrations could significantly improve the expression of HSP 72. The expression of HSP 72 in the vascular endothelial cells cultured in culture medium with 1.0 mg/ml Xingding Injection was the highest, and there was no more increase of expression when the concentration was higher, instead the expression decreased. CONCLUSION: Xingding Injection can protect the vascular endothelial cells from injury during stress. It may be one of its mechanisms in preventing and treating cardio-cerebrovascular disorders.

Diverse effects of long-term treatment with imidapril and irbesartan on cell growth signal, apoptosis and collagen type I expression in the left ventricle of spontaneously hypertensive rats.

To compare diverse effects of angiotensin II type 1 receptor antagonists (irbesartan) and angiotensin converting enzyme inhibitors (imidapril) on left ventricular remodeling in spontaneously hypertensive rats (SHR). Thirty male SHR were randomly divided into three groups: SHR-IR (treated with irbesartan, 50 mg/kg), SHR-IM (imidapril, 3 mg/kg), SHR-C (placebo). Ten male Wistar Kyoto rats (WKY) treated with placebo acted as the control. All treatments were administered once daily from 14 to 27 weeks of age. Imidapril and irbesartan have the similar inhibitor effects on blood pressure and left ventricular mass indexes in SHR. Despite both drugs suppressed ERK-1 protein expression, decreased cardiomyocytes apoptosis index, blocked collagen type I deposition, reduced TGF-beta(1) gene expression in SHR, imidapril elicits a stronger inhibitory effect. Irbesartan had little effect on MKP-1 protein expression, but imidapril decreased it significantly. As a result, the ERK-1/MKP-1 ratio in SHR-IR was significantly greater than that in SHR-IM (P < 0.05). These results suggest that the balance between MKP-1 and ERKs in myocardial tissue is important for cardiac cell proliferation and growth. They also indicate that the similar efficacy of antihypertensive treatment in reducing blood pressure does not predict the similar capacity to control the individual facet of left ventricular remodeling. Irbesartan is more effective in regressing the homeostasis between ERK-1 and MKP-1, however imidapril is superior in suppressing apoptosis and collagen synthesis in cardiac tissue.