Bone marrow-derived dendritic cells rather than spleen-derived dendritic cells can generate regulatory T cells / 中国实验血液学杂志

There are many evidences that dendritic cells (DC) can establish and maintain immunological tolerance through inducing the differentiation of regulatory T cells Treg. This study was purposed to explore the possibility to gene-rate Treg from bone marrow-derived DC (BM-DC) or spleen-derived DC (spDC) generated CD4(+) CD25(+) FOXP3(+) Treg by induction. Bone marrow immature DC (imDC) induced from bone marrow precursor cells of C57BL/6 mice by GM-CSF and IL-4; after culture for 6 day, imDC were stimulated by LPS for additional 16 hours and the mature DC (mDC) have been got; the spDC were collected from spleen of C57BL/6 mice by MACS. Co-culturing fresh BALB/c mouse CD4(+) T cells with these three sorts of DC above mentioned respectively was performed to generate CD4(+) CD25(+) FOXP3(+) Treg. The expression of FOXP3 in CD4(+) T cells was detected by flow cytometry, and the capacity of different DC generated CD4(+) CD25(+) FOXP3(+) Treg was evaluated. The results showed that stimulated by C57BL/6 immature or mature DC, the positive rate of FOXP3 in BALB/c CD4(+) T cells increased from (8.57 ± 1.14)% to (15.80 ± 1.35)%, (17.93 ± 1.45)% respectively (P < 0.01); while stimulated by spDC, the positive rate of FOXP3 in BALB/c CD4(+) T cells decreased from (8.57 ± 1.14)% to (3.95 ± 0.79)% (P < 0.05). It is concluded that the BM-DC but not spDC can generate Treg from CD4(+) T cells, BM-DC may mediate immune tolerance rather than the immune response.

Development of a real-time PCR method for the detection of bacterial colonization in rat models of severe acute pancreatitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Techniques for the fast and accurate detection of bacterial infection are critical for early diagnosis, prevention and treatment of bacterial translocation in clinical severe acute pancreatitis (SAP). In this study, the availability of a real-time PCR method in detection of bacterial colonization in SAP rat models was investigated.</p><p><b>METHODS</b>Samples of blood, mesenteric lymph nodes (MLN), pancreas and liver from 24 specific pathogen-free rats (8 in a control group, 16 in a SAP group) were detected for bacterial infection rates both by agar plate culture and a real-time PCR method, and the results were made contrast.</p><p><b>RESULTS</b>Bacterial infection rates of the blood, MLN, pancreas and liver in the SAP group and the control group by the two different methods were almost the same, which were 5/16, 12/16, 15/16, 12/16 in the SAP group compared with 0/8, 1/8, 0/8, 0/8 in the control group by agar plate culture, while 5/16, 10/16, 13/16, 12/16 and 0/8, 1/8, 0/8, 0/8 respectively by a real-time PCR method. Bacterial number was estimated by real-time PCR, which showed that in the same mass of tissues, the pancreas contained more bacteria than the other three kinds of organs in SAP rats (P < 0.01), that may be due to the edema, necrosis and hemorrhage existing in the pancreas, making it easier for bacteria to invade and breed.</p><p><b>CONCLUSION</b>Fast and accurate detection of bacterial translocation in SAP rat models could be carried out by a real-time PCR procedure.</p>

Systematic review on safety and efficacy of laparoscopy-assisted distal gastrectomy with D2 lymph node dissection for gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To evaluate the safety and efficacy of laparoscopy- assisted distal gastrectomy (LADG) with D2 lymph node dissection for gastric cancer.</p><p><b>METHODS</b>Literature search was performed in Pubmed, Medline, EMBASE, the Chinese Biomedical Database (CBM) to identify controlled trials comparing LADG and open distal gastrectomy (ODG) for gastric cancer published between January 2005 and February 2010. A meta-analysis was performed using RevMan 5.0 software.</p><p><b>RESULTS</b>Seven controlled trials were included. One trail was randomized controlled trial. Compared to ODG, LADG had less blood loss[WMD: -132.04, 95% confidence interval (CI): -207.32 to -56.77], earlier postoperative first flatus (WMD: -0.82, 95% CI: -1.20 to -0.45], less complications [odds ratio (OR): 0.45, 95% CI: 0.26 to 0.78], shorter postoperative hospital stay (WMD: -3.63, 95% CI: -4.19 to -3.07), more harvested lymph nodes (WMD: 1.93, 95%CI: 0.36 to 3.50). There were no significant differences between the two groups in recurrence rate, metastasis rate, mortality and survival rate.</p><p><b>CONCLUSION</b>Short-term outcome of LADG with D2 lymph node dissection for gastric cancer is superior to ODG.</p>

Construction of rAAV2-GPIIb/IIIa vector and test of its expression and function in vitro / 中国实验血液学杂志

This study was aimed to explore the possibility of rAAV2 vector-mediating gene therapy for Glanzmann' s thrombasthenia. The rAAV2-GPIIb/IIIa vector was constructed. The GPIIb/IIIa gene expression in mammal cell were examined by different methods, such as: detection of mRNA expression in BHK-21 cells after 24 hours of infection (MOI = 1 x 10(5) v.g/cell) was performed by RT-PCR; the relation between MOI and quantity of GPII6/IIIa gene expression was detected by FACS after 48 hours of infection; GPIIb/IIIa protein expression in BHK-21 cells after 48 hours of infection (MOI = 10(5) v x g/cell) was assayed by Western blot, GPIIb/IIIa protein expression on cell surface was detected by immunofluorescence, and the biological function of expressing product was determined by PAC-1 conjunct experiments. The results showed that GPIIb/IIIa gene expression in mRNA level could be detected in BHK-21 cells after 24 hours of infection at MOI = 1 x 10(5) v x g/cell and the GPIIb/IIIa gene expression in protein level could be detected in BHK-21 cells after 48 hours of infection at MOI = 1 x 10(5) v x g/cell. In certain range, quantity of GPIIb/IIIa gene expression increased with MOI, but overdose of MOI decreased quantity of GPIIb/IIIa gene expression. Activated product of GPIIb/IIIa gene expression could combined with PAC-I, and possesed normal biological function. In conclusion, rAAV2 vactor can effectively mediate GPIIb and GPIIIa gene expressing in mammal cells, and the products of these genes exhibit biological function. This result may provide a basis for application of rAAV2 vector in Glanzmann's thrombasthenia gene therapy in furture.

Transfection efficiency of adenoviral vector AD5/F35 to malignant hematopoietic cells of different origins / 中国实验血液学杂志

This study was aimed to investigate the transfection efficiency of adenoviral vector AD5/F35 to hematopoietic malignant cells lines of various origins and AD5/F35 cytotoxicity. The hematologic malignant cell lines of various origins were transfected by AD5/F35-EGFP at different multiple of infection (MOI) and AD5-EGFP was used as control; the proportion of fluorescence positive cells was detected by flow cytometry; the killing effect of virus on infective target cells was assayed by MTT and observed by fluorescence microscopy. The results showed that the transfection efficiency of AD5/F35 vector to cell line of myeloid origin was > 99% at MOI = 30, the transfective efficiency of AD5 vector was 26.4% at MOI = 1,000; the transfection efficiency of AD5/F35 vector and AD5 vector to cell line of B cell origin were 11.7% and 5.7%, respectively, at MOI = 1,000. AD5/F35 and AD5 vectors could not effectively transfect cells of T cell origin, no fluorescence positive cells were detected at MOI = 1,000; no significant killing effect of AD5/F35 vector on infective target cells was observed at MOI = 1,000. It is concluded that AD5/F35 vector infection has definite selectivity to hematologic malignant cells of various origin, the infection ability of AD5/F35 vector to cells of myeloid origin is stronger than that to cells of B cell origin, the cytotoxicity of AD5/F35 vector to infective target cells is small. The AD5/F35 vector is preferable to AD5 vector in respect of infection ability and offers good prospects of application in gene therapy for myeloid leukemia cells as target cells.