Abstract: Objective To investigate the phonetype and tolerogenic function of semimature dendritic cells (DC) transfected by myeloid differentiation marker 88（MyD88） small interfering ribonucleic acid（siRNA）. Methods Bone marrow of BALB/c mice was inoculated and cultured in vitro，and induced into DC by 10ng/ml recombinated granulocyte macrophage colony stimulating factor (rmGM-CSF) ，then DC was divided into three groups at the 8th day: blank control group: added nothing; lipopolysaccharide （LPS）group: added with 1μg/ml LPS; and experimental group: added with 1μg/ml LPS after transfected by MyD88 siRNA for 4 hours. The phonetype of three groups was analysed by fluorescenceactivated cell sorting (FACS). The concentration of interleukin 10（IL-10）and interleukin 12（IL-12） in culture supernatant was detected by enzyme linked immunosorbent assay（ELISA）.The function of stimulating alloreactive T cell roliferation were evaluated by primary and secondary mixed lymphocyte reaction （MLR）. The cardiac allograft survival time was compared after DC of three groups injected into recipient mice. Results The phonetype of blank control group DC was CD11c＋，CD25-，CD40low，CD80low，CD86low，MHC-Ⅱlow， which could be induced to mature DC by LPS. Experimental group DC was phonetypically semimature DC (CD11c＋，CD25－，CD40mid，CD80low，CD86low，MHC-IIid) and the IL-10/IL-12 ratio of semimature DC increases significantly. yporesponsiveness of alloactive T cells can be induced by experimental group DC and the survive time of heart allograft was prolonged. Conclusion Immature DC could become semimature DC after transfected by MyD88 siRNA and stimulation by LPS. These semimature DC are more tolerogenic than immature DC.
Objective To explore the impact of recombinant human growth hormone （rhGH） on T lymphocyte subsets in patients with rheumatic heart disease during the perioperative period of heart valve replacement. Methods A total of 65 patients with rheumatic valvular heart disease who received heart valve replacement in Department of Cardiothoracic Surgery of Xiangyang Central Hospital from June 1， 2011 to March 31， 2012 were enrolled in this double-blind randomized controlled clinical study. All the patients were divided into 2 groups by random number produced by SAS software：the trial group and the control group. There were 35 patients in the trial group including 19 males and 16 females with their average age of 50.57 years， and 30 patients in the control group including 16 males and 14 females with their average age of 49.87 years. Apart from routine cardiac glycosides， diuretics， glucose-insulin-potassium solution， and postoperative anti-infective therapy， patients in the trial group also received subcutaneously injection of rhGH 5 U （1 ml）daily from 1 day before surgery to 3 days after surgery， and patients in the control group received subcutaneously injection of normal saline 1 ml as placebo. Peripheral venous blood samples were taken in the morning 2 days before surgery and 1 st， 3 rd， 7 th day after surgery respectively. Percentages of CD3+， CD4+， CD8+ were examined timely by flow cytometry and CD4+ /CD8+ ratio was calculated. Results In the control group， percentages of CD3+， CD4+ and CD4+ /CD8+ ratio on the 1st， 3rd， 7th postoperative day were significantly lower than preoperative levels， and percentages of CD8+ on the 1st and 3rd postoperative day were significantly lower than preoperative level （P＜0.05）. In the trial group， percentages of CD3+， CD4+， and CD8+ on the 1st and 3rd postoperative day were significantly lower than preoperative levels（P＜0.05）， while percentages of CD3+， CD4+， and CD8+ on the 7th postoperative day were not statistically different from preoperative levels （P＞0.05）; CD4+ /CD8+ ratio on the 1st postoperative day was significantly lower than preoperative level （P＜0.05）， while CD4+ /CD8+ ratios on the 3rd and 7th postoperative day were not statistically different from preoperative level （P＞0.05）. There was no statistical difference in preoperative T lymphocyte subsets between the trial group and the control group （P＞0.05）. The percentages of CD4+ and CD4+/CD8+ ratio in the trial group were significantly higher than those of the control group on the 1st postoperative day （P＜0.05）， while the percentages of CD3+ and CD4+ and CD4+ /CD8+ratio in the trial group were significantly higher than those of the control group on the 3rd and 7th postoperative day（P＜0.05）. Conclusion Use of rhGH can significantly increase T lymphocyte subsets expression， enhance body cellular immunity， and improve postoperative recovery of patients with rheumatic valvular heart disease during the perioperative period of heart valve replacement.
Objective To evaluate the biomechanical stability of a newly-designed Y type pedicle screw (YPS) in osteoporotic synthetic bone. Methods The osteoporotic synthetic bone were randomly divided into 3 groups (n=20). A pilot hole, 3.0 mm in diameter and 30.0 mm in deep, was prepared in these bones with the same method. The YPS, expansive pedicle screw (EPS), and bone cement-injectable cannulated pedicle screw (CICPS) were inserted into these synthetic bone through the pilot hole prepared. X-ray film examination was performed after 12 hours; the biomechanical stability of YPS, EPS, and CICPS groups was tested by the universal testing machine (E10000). The test items included the maximum axial pullout force, the maximum running torque, and the maximum periodical anti-bending. Results X-ray examination showed that in YPS group, the main screw and the core pin were wrapped around the polyurethane material, the core pin was formed from the lower 1/3 of the main screw and formed an angle of 15° with the main screw, and the lowest point of the inserted middle core pin was positioned at the same level with the main screw; in EPS group, the tip of EPS expanded markedly and formed a claw-like structure; in CICPS group, the bone cement was mainly distributed in the front of the screw and was dispersed in the trabecular bone to form a stable screw-bone cement-trabecular complex. The maximum axial pullout force of YPS, EPS, and CICPS groups was (98.43±8.26), (77.41±11.41), and (186.43±23.23) N, respectively; the maximum running torque was (1.42±0.33), (0.96±0.37), and (2.27±0.39) N/m, respectively; and the maximum periodical anti-bending was (67.49±3.02), (66.03±2.88), and (143.48±4.73) N, respectively. The above indexes in CICPS group were significantly higher than those in YPS group and EPS group (P<0.05); the maximum axial pullout force and the maximum running torque in YPS group were significantly higher than those in EPS group (P<0.05), but there was no significant difference in the maximum periodical anti-bending between YPS group and EPS group (P>0.05). Conclusion Compared with EPS, YPS can effectively enhance the maximum axial pullout force and maximum rotation force in the module, which provides a new idea for the design of screws and the choice of different fixation methods under the condition of osteoporosis.