Biomedical subjects

Shi-Ping Chen

Publications and source records attributed to Shi-Ping Chen.

10 recordsLinked to original sources

PubMed2007

Functional advantage of NPC-related V-val subtype of Epstein-Barr virus nuclear antigen 1 compared with prototype in epithelial cell line.

Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC) and the viral nuclear antigen 1 (EBNA1) plays a crucial role in viral latency. Three EBNA1 subtypes, P-ala, V-thr and V-val have been detected from healthy carriers in Guangzhou area. A close relation of V-val EBNA1 with NPC was suggested by its preference to infect NPC cells. We therefore investigated the functional difference among these three EBNA1 subtypes in human epithelial cell line. The three coding sequences of the EBNA1 subtypes were cloned into the pGFP-C2 vector, and transfected into 293 cells, respectively. Effect of EBNA1 expression on cell proliferation was examined. The maintenance activity and expression level of EBNA1-plasmid in 293 cells were evaluated by using GFP as a reporter. The expression of P-ala, V-thr or V-val EBNA1 had no effect on 293 cell growth, while the relative average intensity of fluorescence after 14-day selection in V-val-EBNA1/293 cells was statistically higher than P-ala-EBNA1/293 (P<0.05, t test). We suggest that V-val EBNA1 with the functional advantage compared with prototype shown in this study might contribute to the tumorigenesis of NPC by increasing the expression of itself or other viral or cellular genes.

Cell Growth Processes↗

PubMed2006

Nitrogen response efficiency increased monotonically with decreasing soil resource availability: a case study from a semiarid grassland in northern China.

The concept of nutrient use efficiency is central to understanding ecosystem functioning because it is the step in which plants can influence the return of nutrients to the soil pool and the quality of the litter. Theory suggests that nutrient efficiency increases unimodally with declining soil resources, but this has not been tested empirically for N and water in grassland ecosystems, where plant growth in these ecosystems is generally thought to be limited by soil N and moisture. In this paper, we tested the N uptake and the N use efficiency (NUE) of two Stipa species (S. grandis and S. krylovii) from 20 sites in the Inner Mongolia grassland by measuring the N content of net primary productivity (NPP). NUE is defined as the total net primary production per unit N absorbed. We further distinguished NUE from N response efficiency (NRE; production per unit N available). We found that NPP increased with soil N and water availability. Efficiency of whole-plant N use, uptake, and response increased monotonically with decreasing soil N and water, being higher on infertile (dry) habitats than on fertile (wet) habitats. We further considered NUE as the product of the N productivity (NP the rate of biomass increase per unit N in the plant) and the mean residence time (MRT; the ratio between the average N pool and the annual N uptake or loss). The NP and NUE of S. grandis growing usually in dry and N-poor habitats exceeded those of S. krylovii abundant in wet and N-rich habitats. NUE differed among sites, and was often affected by the evolutionary trade-off between NP and MRT, where plants and communities had adapted in a way to maximize either NP or MRT, but not both concurrently. Soil N availability and moisture influenced the community-level N uptake efficiency and ultimately the NRE, though the response to N was dependent on the plant community examined. These results show that soil N and water had exerted a great impact on the N efficiency in Stipa species. The intraspecific differences in N efficiency within both Stipa species along soil resource availability gradient may explain the differences in plant productivity on various soils, which will be conducive to our general understanding of the N cycling and vegetation dynamics in northern Chinese grasslands.

China↗

PubMed2006

Identification of a new target region on the long arm of chromosome 7 in gastric carcinoma by loss of heterozygosity.

AIM: To define the common deleted region on the long arm of haman chromosome 7q linked to primary gastric carcinomas in Chinese by loss of heterozygosity (LOH) and its clinical significance. METHODS: Nine microsatellite markers distributed over chromosome 7q with an average marker density of 10cM were used to examine 70 primary gastric carcinomas for LOH by PCR amplification. The PCR products were separated by electrophoresis on polyacrylamide gel. Genescan and Genotyper softwares were used to analyze LOH. RESULTS: LOH with at least one marker on 7q occurred in 34.3% (12/50) of the tumors. Among them, LOH at D7S486 and D7S798 was higher in 24.0% (24/70) and 19.2% (5/26), respectively. By statistical analysis we also observed an obvious genotype-phenotype correlation on 7q (P<0.05). The frequency of LOH at D7S486 in patients with lymph node metastasis was significantly higher than that in those without lymph node metastasis (P=0.015). CONCLUSION: The high incidence of LOH at D7S486 and its correlation with poorer prognosis suggest that there might be putative tumor suppressor genes in this region involved in the tumorigenesis and progression of gastric carcinoma.

Adult↗

PubMed2006

Loss of heterozygosity analysis of a candidate gastric carcinoma tumor suppressor locus at 7q31.

Gastric carcinoma is one of the most common malignancies in Asia. Although the allelic deletion of 7q has been reportedly associated with primary gastric carcinoma tumorigenesis, no predisposing genes in this region have been identified so far. Here, we report the results of genotype and loss of heterozygosity (LOH) analysis on 7q in this tumor. A panel of nine microsatellite markers distributed over the whole chromosome 7q was used for genotyping primary gastric carcinomas. Of 72 primary tumors LOH of D7S486 occurred in 24.0% (12/50) of cases. Fine mapping with 12 additional markers flanking D7S486 resulted in LOH of 30.36% (17/56) and defined one minimal deleted region in primary gastric carcinomas, a 90-kilobase region bounded by D7S2543 and D7S486 at 7q31.2. The allelic deletion correlates statistically with clinicopathologic variables. Our data suggest a possible link between putative tumor suppressor genes and gastric carcinoma in the 7q31 region.

Adult↗

PubMed2006

Betanodavirus induces phosphatidylserine exposure and loss of mitochondrial membrane potential in secondary necrotic cells, both of which are blocked by bongkrekic acid.

In this study, we show how the red spotted grouper nervous necrosis virus (RGNNV) causes loss of mitochondrial membrane potential and promotes host secondary apoptotic necrosis. RGNNV viral proteins such as protein alpha (42 kDa) and protein A (110 kDa) were quickly expressed between 12 h and 24 h postinfection (p.i.) in GL-av cells. Annexin V staining revealed that the NNV infection of GL-av cells induced phosphatidylserine (PS) externalization and development of bulb-like vesicles (bleb formation) at 24 h p.i. NNV infection also induced DNA fragmentation detectable by TUNEL assay between 12 h (8%) and 72 h (32%) p.i. Bongkrekic acid (1.6 microM; BKA) blocked permeability of the mitochondrial permeability transition pore, but cyclosporine A (CsA) did not block secondary necrosis. Finally, secondary necrotic cells were not engulfed by neighboring cells. Our data suggest that RGNNV induces apoptotic death via opening the mitochondrial permeability transition pore thereby triggering secondary necrosis in the mid-apoptotic phase.

Apoptosis↗

PubMed2006

[Efficacy of autologous renal tumor cell lysate-loaded dendritic cell vaccine in combination with cytokine-induced killer cells on advanced renal cell carcinoma--a report of ten cases].

BACKGROUND & OBJECTIVE: Nowadays, operation is the main treatment for renal cell carcinoma (RCC). But the prognosis of advanced RCC is poor because of its high recurrence rate and resistance to conventional treatments, such as chemotherapy and radiotherapy. Hence, novel and more effective therapeutic options for advanced RCC are needed. This study was to evaluate the clinical efficacy of autologous renal tumor lysate-loaded dendritic cells (DCs) in combination with cytokine-induced killer (CIK) cells on advanced RCC. METHODS: Peripheral blood mononuclear cells were isolated from 10 patients with advanced RCC, and cultured with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) to produce DCs. The DCs were pulsed with autologous renal tumor cell lysate. T lymphocytes were cultured with interferon-gamma (IFN-gamma), IL-2, CD3-moAb, and IL-1alpha to prepare CIKs. After nephrectomy, the patients received intradermal DC vaccination weekly for at least 8 times, and CIKs administration biweekly for at least 4 times. Clinical and immunologic responses were evaluated by imaging examination, T lymphocytes subset changes, and delayed-type hypersensitivity (DHT) reaction, respectively. RESULTS: During follow-up of 6-20 months (median, 11 months), 1 case of partial remission (PR), 2 cases of stable disease (SD), and 1 case of progressive disease (PD) were identified in the 4 patients with measurable diseases; 1 case of PD was identified in the 6 patients with no measurable diseases, 1 case was lost, and no progressive disease was identified. When treated for 2 months, the levels of CD3+, CD4+, CD4+/CD8+, CD56+ were increased significantly (P<0.05) as compared with those before treatment. DTH reaction was positive in 6 patients, including the patient with PR. Except transient fever and chill, no remarkable adverse event happened during or after the treatment. CONCLUSION: Autologous tumor cell lysate-pulsed DCs in combination with CIKs shows short-term efficacy on advanced RCC through inducing specific antitumor immunity, and the adverse events are tolerable.

Adult↗

PubMed2006

[Short-term curative efficacy of cytokine-induced killer cells combined micro-invasive treatments on hepatocellular carcinoma].

BACKGROUND & OBJECTIVE: Recently, micro-invasive treatments showed well application prospective in treating primary hepatocellular carcinoma (HCC), while tumor immunotherapy is a hot topic in tumor treatment. This study was to investigate the efficacy of cytokine-induced killer cells (CIK) combined micro-invasive treatments (transcatheter arterial chemoembolization and radiofrequency ablation) on the recurrence of HCC. METHODS: A total of 85 HCC patients without active lesions and metastasis, which were displayed by imaging examination after transcatheter arterial chemoembolization and radiofrequency ablation therapy, were divided randomly into 2 groups: 45 in study group, and 40 in control group. The patients in study group were transfused with CIK cells through hepatic artery after micro-invasive treatments, while the patients in control group were not. The levels of T lymphocyte subsets and native killer (NK) cells in peripheral blood of HCC patients before and after CIK cell transfusion were detected by flow cytometry (FCM). Tumor condition was observed by CT scanning every 2-3 months. RESULTS: The percentages of CD3+, CD4+, and CD56+ effect cells and the proportion of CD4+/CD8+ were increased from (68.6+/-11.0)%, (31.0+/-9.0)%, (15.6+/-7.8)%, and 1.1+/-0.5 to (70.7+/-10.1)% (P<0.05), (33.5+/-8.0)% (P<0.05), (18.4+/-9.4)% (P<0.05), and 1.3+/-0.6 (P<0.05) after CIK cell transfusion; while the percentages of CD8+ and CD3+ CD56+ cells were decreased from (31.1+/-7.8)% and (6.4+/-3.5)% to (28.6+/-8.3)% (P<0.05) and (5.2+/-3.3)% (P<0.05). The 1- and 1.5-year recurrence rates were 8.89% and 15.56% in study group, and 30.00% and 40.00% in control group (Chi(2) = 4.87 and 6.41, P <0.05). CONCLUSION: CIK cell transfusion after micro-invasive treatments may improve the immunologic function in HCC patients, and play an important role in reducing the recurrence rate of HCC.

Adult↗

PubMed2006

[Listeria-induced host cellular actin cytoskeleton rearrangement and phospholipase D].

Either phagocytosis of macrophage to pathogen or pathogen-induced invasion into non-professional phagocytes, such as epithelial cells, require actin cytoskeletal rearrangements and remodeling of the plasma membrane, which are regulated precisely by monogeric GTPase and the correlated proteins. As a key signaling molecule in the cell, phosphotidicphospholipase D (PLD) regulates or interacts directly with cellular actin cytoskeleton rearrangement. Phospholipase D plays an important role in FcgammaRI and C-reactive protein-mediated phagocytosis and phosphorylated cofilin, a ADF (actin depolymerizing factor) is able to bind to phospholipase D and stimulate it; meanwhile, the Listeria-induced actin cytoskeleton rearrangement during the infection is controlled by the phosphorylation of cofilin. Thus, it made challenge to disclose the function of PLD on the regulation of Listeria-induced actin cytoskeleton rearrangement during infection, furthermore, it may provide us more understanding on the role of PLD in the infection and inflammation, which is essential to dissect the molecular mechanism of bacterial-host interaction more thoroughly.

Actins↗

PubMed2003

Determination of the orientation of azathioprine adsorbed on a silver electrode by SERS and ab initio calculations.

We report the SERS spectrum of azthioprine (AZA) on a silver electrode surface and the results of normal mode calculations using empirical and ab initio calculations of the 6-mercaptopurione (6-MP) component of AZA. The empirical calculations were done with a Urey-Bradley force field (UBFF) and the ab initio calculations with the STO-3G basis set using the UHF, MP2 and BLYP methods. From the difference between the SERS and solid spectra, we determined that AZA attaches edge-on to the surface through the N3 site on the 6-MP component of the molecule. The UBFF calculation on an Ag adatom-molecule model reproduced most of the main observed frequency shifts in the SERS spectrum. With a similar model, the ab initio calculations yielded frequency shifts in the same direction as the one observed for the in-plane normal modes, but they yielded opposite shifts for the out-of-plane normal modes. This phenomenon may be attributed to a face-on interaction of the 6-MP component with a neighboring adatom made possible by an inclination of the molecule on the surface.

Azathioprine↗

PubMed2003

[Application of double immunomagnetic positive sorting to ex vivo expansion of marrow CD34(+)CD59(+) cells from patients with paroxysmal nocturnal hemoglobinuria].

Since flow cytometry was not feasible for sorting a huge amount of cells for clinical use, the method of double immunomagnetic positive sorting was used for selection of CD34(+)CD59(+) cells from bone marrow mononuclear cells in patients with paroxysmal nocturnal hemoglobinuria (PNH), which laid the groundwork for clinical ABMT/APBSCT of patients with PNH. Immunomagnetic positive selection was used for two times, the microbeads were removed from the CD34(+) cells selected firstly by means of overnight culture, then the sufficient CD34(+)CD59(+) cells were used for ex vivo expansion. The results showed that the survival, proliferation and colony-forming units of the selected CD34(+)CD59(+) cells by double immunomagnetic positive sorting had no significant difference as compared with that of CD34(+)CD59(+) cells selected by flow cytometry technique. It is suggested that the double immunomagnetic positive sorting promotes the use for separation and purification hematopoietic stem/progenitor cells and other cells with double or multiple markers cells for autologous hematopoietic stem cell transplantation in PNH patients.

Antigens, CD34↗