Virus-like particles ( VLPs ) are particles formed by one or several structural proteins from viruses with similar outside structure and antigenicity of the native viruses containing no virus genome.VLPs antigen can be produced in yeasts, mammalian cells, plant cells, insect cells and bacteria.VLPs vaccine can induce immune response effectively.Other adjuvant or polypeptide can be integrated into VLPs to construct chimeric vaccines.This review focuses on research progress of virus-like particles and its application in the prevention and control of infectious diseases.

Objective To evaluate the use of magnifying endoscopy combined with narrow band im-aging (NBI) system in diagnosis of early gastric cancer. Methods From March 2008 to December in 2008, a total of 56 patients with suspected gastric mucosal lesions were enrolled in the study. The lesions were ob-served with magnifying endoscopy combined with NBI and indigo-earmine-chromoendoscopy, and the results were compared with pathologic diagnosis from targeted biopsies. Results Out of 56 patients, 16 were diag-nosed as early gastric cancer pathologically. The accordance rate with the pathological diagnosis, sensibility, specificity, false positive rate and false negative rate of the magnifying endoscopy combined with NBI system were 94.6% (53/56), 93. 8% (15/16), 95.0% (38/40), 5.0% (2/40) and 6. 3% (1/16), respec-tively; while those of chromoendoscopy were 91.1% (51/56), 87. 5% (14/16), 92. 5% (37/40), 7. 5% (3/40) and 12. 5% (2/16), respectively (P >0.05). There was no difference between NBI and chro-moendoscopy in regarding of observing pit pattern, however, NBI was superior in displaying intrapapillary capillary loop. Conclusion Combination of magnifying endoscopy and NBI provides clear images of gas-tric mucosa and intrapapillary capillary, which is useful in diagnosis of early gastric cancer and can improve accuracy of biopsy. When combined with chromoendoscopy, it can further improve the yield of diagnosis.

Objective To investigate the clinic and endosoopic features of left-sided portal hypertension ( LSPH). Methods Eight patients with left-sided portal hypertension were analyzed retrospectively. Results The main manifestations of patients with LSPH were hematemesis, hematochezia, splenomegaly and hypersplenism. The patients have the features of pancreatic disease, but without the evidences of hepatic disease. Solitary gastric varices account for 62. 5% , both gastric and esophageal varices account for 37. 5% . The patients with features of LSPH often mislead to diagnose as blood diseases or portal hypertension resulted from hepatic cirrhosis. Conclusions Pancreatic diseases may lead to portal hypertension, solitary gastric varices were the important evidence of left-sided portal hypertension.

Objective To compare the effectiveness and adverse effects among three groups of patients with esophageal achalasia treated with small balloon dilation and/or intrasphincteric injection of botulinum toxin. Methods Forty-eight patients were divided randomly into three groups, A, B, and C, treated with small balloon dilation, intrasphincteric injection of botulinum toxin, and combination of these two respectively. At 1 week, 3 months and 1 year after treatment, the clinical scores, lower oesophageal sphincter-ic pressure, and lower oesophageal sphincteric relax rate in three groups were compared. Results At 1 week, 3 months and 1 year after treatment, the effective rates and gaps of pre - and post - treatment LESP and LESRR were higher in group B and C than those in group A. There were no differences between BT group and combination group at 1 week and 3 months, but in 1 year after treatment the effective rates and gaps of LESP and LESRR in combination group were higher than those in BT group. Complications never happened in all groups. Conclusion The combination of small balloon dilation and intrasphincteric injection of botulinum toxin was the effective procedure with the advantages of lasting longer time, less complications and milder chest pain.

Objective To study the apoptosis of pancreatic cancer cells induced by a retroviral vector containing antisense human telomerase RNA gene. Methods Sense and antisense telomerase RNA genes were transfected into Can-pan-2 cell line by electroporation,and selected with G418 to get stable transfection and retrovirus yielding cell lines. We transfected Can-pan-2 cell with concentrated retroviral supernatant,and selected with G418 to get stable transfection cell lines,The expression of the aim gene in Can-pan-2 cell was confirmed through PCR,while TRAP-PCR-ELISA was used to determine the telomerase activity,and immunofluorescence was adopted to determine reproductive activity of the infected cells,flow cytometry(FCM)was used to detect cell apoptosis.ResultsThe titer of sense and antisense recombinant retrovirus reached 0.95?106 CFU/mL and 1.1?106 CFU/mL respectively,PCR demonstrated that the telomerase RNA genes were successfully intergrated into the target cells’ genome,The cell growth and telomerase activity of Can-pan-2 were significantly inhibited and apoptosis occurred after antisense virus infection. Conclusion Antisense human telomerase RNA may inhibite telomerase activity of pancreatic cancer cells and promote apoptosis of the cells.

Objective:To investigate the inhibitory effect of antisense human telomerase RNA(hTR) gene on implanted hepatocellular carcinoma in nude mice.Methods: HepG2 cells were subcutaneously inoculated into BALB/c nude mice at the axilla to establish implanted hepatocellular carcinoma model.The retrovirus plasmid containing antisense telomerse RNA(PLXSN-hTR-BamHⅠ) was injected into the tumor(0.2 ml every time,5 times).Retrovirus plasmid containing sense telomerase RNA(PLXSN-hTR-EcoRⅠ) and normal saline were inoculated as control groups.Tumor volume was determined and the inhibitory rate was calculated.Tumor necrosis was observed by histological analysis and cell apoptosis was analyzed by terminal transferase dUTP nick end labeling(TUNEL).Results: Tumor growth in antisense hTR group was significantly inhibited compared with the two control groups.The tumor inhibitory rate(26.78%) of antisense hTR group was significantly higher than that of sense hTR group(1.93%,P

Objective To study the relationship between expression of Fas ligand (FasL) in colorectal cancer tissues and apoptosis of tumor-infiltrating lymphocytes (TIL). Methods FasL protein and its mRNA were measured by immunohistochem istry and in situ hybridization in the consecutive tissue slices of 30 colorecta l cancers respectively. Immunohistochemistry and terminal deoxynucleotidyl tra nsferase mediated dUTP nick end labeling assay (TUNEL) were used to detect the cell count of TIL and the count of TIL being apoptosis in both negative and pos i tive regions of FasL in the consecutive tissue slices of cancers respectively. T UN EL method was used to detect apoptosis of tumor cells among different FasL expre ssion regions. Results ①High expression of FasL was examined in 30 cases of colo rectal cancer; there were expressions of FasL in more than 75% tissues in each slice. ②In the consecutive tissue slices, the location of expression of FasL protein corresponded with that of FasL mRNA. ③FasL expression was not eve n in the same or among different tissues. The cell count of TIL was less in FasL positive region than that in FasL negative region in the same tissue, the latt er be ing as 2.88 times as the former. ④ The cell count of TIL being apoptotic in the positive regions was as 2.13 times as that in the negative ones. ⑤ Apoptotic r ate of tumor cells was higher in FasL negative region (81.2%) than that in FasL positive region (47.4%, P

Aim To investigate the expression and regulation characteristics of the Substance P receptor(Neurokinin-1R, NK-1R) in human skin keratinocytes and fibroblasts. Methods HaCaT cells,a human keratinocyte cell line, and fibroblasts were cultured. The expression of NK-1R protein was examined by immunohistochemisury technique,and the mRNA level was detected by reverse transcriptase polymerase chain reaction (RT- PCR). The expression and regulation of NK-1R were measured by flow cytometry in HaCaT cells and fibroblasts treated with various stimuli and drugs. Results The expression of NK-1R existed in human keratinocyte and fibroblast, mainly located on cell membranes and cytoplasma. The NK-1R also expressed at HaCaT cells and fibroblasts transcription levels, and the mRNA levels in HaCaT cells were higher than that of fibroblasts. SP and IFN-? might upregulate the membrane expressions of NK-1R in both the two cells, while LPS might downregulate the expressions of NK-1R. Cetirizine and Spantide I can degrade the expressions of NK-1R in the two kinds of cells.Conclusions The human keratinocytes and fibroblasts can express NK- 1R at cell, protein and transcription levels, and the expression characteristics can be regulated by some inflammatory factors, it indicates the keratinocytes and fibroblasts were involved in the regulation of skin immune and NK-1R may play an important role in skin inflammation.

Objective To evaluate the clinical responses and side effects of non sealed colloidal 32 P internal radiation and macroaggregate albumin (MAA) for hepatocellular carcinoma (HCC). Methods Twenty six patients with HCC underwent ultrasound guided intratumoral injection therapy of 32 P colloid and MAA. The clinical responses and toxic effects were analyzed on basis of clinical manifestions and laboratory data, including the tumor size, histopathological changes, serum alpha fetoprotein (AFP) estimation, blood routine, hepatic and renal functions and immunocompetence assays before and after treatment. Results Clinical responses: alleviation of symptoms, decreased AFP levels, fibrosis and complete or partial necrosis within tumor lesions (CR 2, PR 13, MR 2, SD 7 and PD 2). The total response rate was 57.7% and the median survival period was 16 months. Hepatic lesions became resectable in 5 patients for whom successful operation was performed. The 1 ,2 and 3 year survival rates were 88.5%, 76.9% and 38.5%, respectively. No evidence of non sealed radionuclide induced toxic reactions or complications were observed. Conclusions The treatment of internal radiation with 32 P colloid and macroaggregate albumin is effective, simple, safe and applicable with wide indications for primary hepatic carcinoma.

Objective: To study the inhibitory effect of retrovirus-mediated antisense human telomerase RNA (hTR) gene on hepatocelluar carcinoma, so as to explore an effective way to inhibit telomrerase activity in the treatment of hepatocellular carcinoma. Methods: Sense and antisense hTR gene were transfected into the packaging cell line PT67 by electroporation, and the stablely transfected cells were selected with G418. The recombinant retroviral supernatant was collected and transfected into HepG2 cells. After G418 selection, PCR was used to verify the integration of the hTR gene. Cell growth curves were drawn using MTT assay and the expression of PCNA was determined by immunofluorescence. TRAP-PCR-ELISA was adopted to detect the telomerase activity; cell cycle and apoptosis were evaluated by flow cytometry (FCM).Results: The expression of hTR gene could be amplified in HepG2-hTR-EcoRⅠ and HepG2-hTR-BamHⅠ cells, but not in untransfected HepG2 cells. The antisense hTR complementary to the template region of telomerase inhibited growth and proliferation of HepG2 cells. The expression of neutrophil proliferating cell nuclear antigen (PCNA) was decreased. Telomerase activity in the antisense hTR-treated group was (2.31?0.16),which was significantly lower than those of the other 2 groups(P