PD-1 expression in HBcAg-specific CD8+ T cells of adolescents with chronic HBV infection / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the differential expression of programmed death-1 (PD-1) in the hepatitis B core antigen (HBcAg)17-28-specific CD8+ T cell subsets of adolescent patients with chronic hepatitis B virus (HBV) infection during the immune tolerant phase and the immune clearance phase.</p><p><b>METHODS</b>A total of 105 patients between the ages of 12-28 years old (mean age 17.20+/-6.35) with chronic HBV infection and 15 healthy age-matched individuals were enrolled in the study. The patients were divided into two groups according to their current status in immune clearance phase (n = 55) or immune tolerant phase (n = 50), as determined by hepatic biopsy pathology. Flow cytometry was used to detect HLA-A2 type and PD-1 expression on peripheral blood mononuclear cells (PBMC) and HBcAg17-28-specific CD8+ T cells. PD-1 mRNA levels in PBMCs were measured by reverse transcription-polymerase chain reaction (RT-PCR). Independent samples t-test was used to compare means between the two groups, and one-way ANOVA was used to compare means among multiple groups. Pearson's correlation coefficient was used to assess the significance of correlation.</p><p><b>RESULTS</b>The frequency of HBcAg18-27-specific CD8+ T cells was significantly higher in the immune clearance phase group than in the immune tolerant phase group (t = 18.08, P less than 0.01), but the expression of PD-1 on the HBcAg18-27 specific CD8+ T cells was significantly lower in the immune clearance phase group than in the immune tolerant phase group (t = 4.72, P less than 0.01). A negative correlation existed between the frequency of HBcAg18-27-specific CD8+ T cells and PD-1 expression (r = -0.463, P less than 0.01). A positive correlation existed between HBV viral load and PD-1 expression on the HBcAg18-27-specific CD8+ T cells in chronic HBV infection patients (r = 0.882, P less than 0.01), and there was a negative correlation between PD-1 expression levels on HBcAg18-27-specific CD8+ T cells and hepatic tissue inflammation score (r = -0.76, P less than 0.01). PD-1 mRNA in PBMCs was significantly higher in the immune tolerant phase group than in the immune clearance phase group (t = 30.89, P less than 0.01).</p><p><b>CONCLUSION</b>Up-regulated expression of PD-1 is associated with HBV-specific CD8+ T cells and may play a crucial role in inhibiting their function during the immune tolerance phase of chronic HBV infection in adolescents.</p>

Fluorescence resonance energy transfer analysis for detecting protein kinase C activation / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a sensitive and direct method for detecting the activation of protein kinase C (PKC) using fluorescence resonance energy transfer (FRET) technique.</p><p><b>METHODS</b>HEK293 cells were transfected with C kinase activity reporter (CKAR) plasmid or/and parathyroid receptor 1 plasmid , and after incubation for 72 h, the fluorescence resonance energy transfer was measured with or without parathyroid or TPA stimulation.</p><p><b>RESULTS</b>TPA reduced the efficiency of FRET and increased the emission ratio of CFP/YFP (C/Y) in HEK293 cells transfected with CKAR. PTH(1-34) could increase the emission ratio of C/Y in HEK293 cells co-transfected with CKAR and PTHR1 but not in cells transfected with CKAR.</p><p><b>CONCLUSION</b>FRET analysis using CKAR can be utilized to detect the activation of PKC, which provides a useful means for studying the signaling pathways associated with PKC.</p>

One stage anterior and posterior fusion and posterior fixation for the treatment of thoracic and lumbar spinal tuberculosis / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effect of one stage anterior and posterior fusion and posterior fixation for the treatment of thoracic and lumbar spinal tuberculosis.</p><p><b>METHODS</b>From March 2003 to December 2006, one stage anterior and posterior fusion and posterior fixation were performed to treat 23 patients who suffered thoracic and lumbar spinal tuberculosis. There were 15 males and 8 females with an average of 37.6 years (17-61 years). 4 cases' tuberculose focus were in thoracic vertebra, 8 cases in thoracolumbar, 11 cases in lumbar.</p><p><b>RESULTS</b>The average follow up period was 28.7 months (9-40 months). The symptoms of all patients had primarily relieved and the patients can ambulate at 2-3 weeks after treatment. At the 6th after operation, the X-ray showed interbody fusion. Frankel grading of 16 patients with incomplete paraplegia were improved averagely 1.62 grades. The major complications including 2 cases of temporary sinus formation, 1 case of fixtor breaking and 1 case of recurring (owing to an inadequate postoperative chemotherapy).</p><p><b>CONCLUSION</b>One stage anterior and posterior fusion and posterior fixation can effectually resect focus, rebuild stability of spine, promote interbody fusion and recovery of incomplete paraplegia in treating thoracic and lumbar spinal tuberculosis.</p>