In this paper, we investigate the boundedness character, the global attractivity and the periodic nature of the svstem of ratiol difference equatious:xn+1=p+yn-k/xn,yn+1=q+xn-k/yn,n=0,1,2..., where p>0, q>0, k∈ of the system of rational difference equations:xn+1=P+yn-k/xn, yn=q+xn-k/yn,n=0,1,2 {1,2,…} and the initial values x1, y1∈(0,∞), i=- k, -k+1,… 0. Some new results are obtained.

Objective To study the effect of c-myc small interference RNA(siRNA) on c-mye protein in leukemic cells, and investigate a new method of gene therapy on leukemia. Methods siRNA against c-myc mRNA were designed and synthesized. The siRNA at 100 nmol/ml density was transfected into HL-60 cells. The cells cultured at 24 h, 48 h or 72 h were collected after being transfected, and the total protein of the cells was extracted according to the instruction booklet of TRIzol reagent. The expression level of c-myc protein was examined by Western blotting. Results After being treated with siRNA of c-myc, the quantity of c-myc protein was obviously reduced. It was remarkably lower than that of the control group. Furthermore after 72 h treatment with siRNA, the expression of c-myc protein reached its lowest. Conclusion The siRNA of c-myc can suppress the expression of c-myc protein in HL-60 cells. There are sequence targeted and time-dependence effect. The siRNA of c-myc may become a new tool of gene therapy on leukemia.

ObjiectiveTo investigate the clinical efficacy of Chinese medicineShuxin-Huoxue decoction on coronary heart disease and angina pectoris.MethodsThis study was a randomized controlled trial. 86 patients with coronary heart disease and angina pectoris and conformed to the indusive criteria were randomly divided into a control group and a treatment group, with 43 cases in each group. The control group was treated with conventional western medicine, the treatment group was treated with traditional Chinese medicineShuxin-Huoxue decoction. Serum homocysteine (Hcy) was measured by enzymatic cycling assay, high sensitive C reactive protein (hs-CRP) was measured by immunotubidimetric assay and left ventricular ejection fraction (LVEF), stroke volume (SV), cardiac output (CO), cardiac index (CI) were measured by color doppler echocardiography before and after treatment. The clinical effect of the two groups was evaluated.ResultsThe total effective rate of the treatment group and the control group was 90.7% (39/43) and 74.4% (32/43) respectively,there was significant difference (χ2=3.957,P=0.047). Followed up for 4 weeks, LVEF(65.7% ± 8.7% vs. 61.5% ± 8.4%,t=2.277), SV(86.9 ± 16.8 ml vs.79.2 ± 16.5 ml,t=2.144), CO(49.3 ± 9.1 ml/m2 vs. 44.7 ± 8.8 ml/m2,t=2.383), CI (3.7 ± 0.9 L/min?m2 vs. 3.3 ± 0.7 L/min?m2,t=2.301) of the treatment group were significantly improved after treatment than those of the control group (P<0.05), and the decrease of serum Hcy  (8.7± 3.7mmol/L vs. 11.4± 3.5mmol/L,t=3.476), hs-CRP (2.7± 1.1 mg/L vs. 3.5± 1.3 mg/L,t=3.081) level of the treatment group were better than those of the control group(P<0.01).ConclusionTraditional Chinese medicineShuxin-Huoxue decoction has good therapeutic effect on coronary heart disease and angina pectoris.

Objective To study the internalization mediated by heat shock protein 70 (HSP70) receptors expressed on the surface of dendritic cells (DCs). Methods DCs from C57BL/6 mouse bone marrow were divided into HSP70 receptor-blocking group, non-receptor-blocking group and control group. The HSP70-FITC positive cells were detected by flow cytometry (FCM). Results FCM indicated that in HSP70 receptor-blocking group, the HSP70 receptors could be almost totally blocked by 50?g HSP70. With the increase of HSP70-FITC dosage, the number of HSP70-FITC positive cells increased. In non-receptor-blocking group, the rates of the HSP70-FITC positive cells were up to 90% either when 50?g HSP70-FITC or 100?g HSP70-FITC was used with no remarkable difference between them. Conclusions The internalization mediated by HSP70 receptors plays a major role in the stage of ingestion of HSP70 with the characteristics of saturation and priority. Once the receptors are blocked, non-receptor pathway participates in internalization in a dose-dependent manner.

The article analyses the current situation of the unbalanced development of Chinese higher medical education and the reasons for it,and points out that to promote its development,gradation and diversify development of education must be realized.

Objective To explore the change of copeptin in plasma and its significance in patients with intracerebral hemorrhage combined with stress ulcer.Methods Eighty patients with intracerebral hemorrhage were collected.Forty-nine patients of pure intracerebral hemorrhage and 31 patients of intracerebral hemorrhage combined with stress ulcer were included.Thirty healthy people were taken as controls.The level of copeptin in plasma was measured and compared in all subjects.Results The level of copeptin in plasma in patients with pure intracerebral hemorrhage and intracerebral hemorrhage combined with stress ulcer was significantly higher than that in controls:(303.684 ± 68.691),(527.034 ± 74.111) ng/L vs.(121.460 ± 53.364) ng/L,and the level of copeptin in plasma in patients with intracerebral hemorrhage combined with stress ulcer was significantly higher than that in patients with pure intracerebral hemorrhage.The differences were statistically significant (P ＜ 0.05).Conclusion The level of copeptin in plasma in patients with pure intracerebral hemorrhage increases significantly,and it is much higher in patients with intracerebral hemorrhage combined with stress ulcer.

Objective To explore the role and their relationship of Ki-67, VEGF and p27 expressed in adult patients with acute leukemia. Methods The expression of Ki-67, VEGF and p27 in bone marrow mononuclear cells (BMMNC) were analyzed by immunocytochemical staining, and their correlations of Ki-67, VEGF and p27 were statistically analyzed. Results The expression of Ki-67(42.48±25.78)% or VEGF (44.89±24.01)% on BMMNC from acute leukemia cells was significantly higher than that in the control (11.40±9.94)% or (16.90±12.54)% (P<0.01). But the expression of p27 (23.65±13.30)% was significantly lower than that in the control (50.23±22.68)% (P<0.01). The expressions of Ki-67 were positively correlated with and VEGF in patients with acute leukemia were positively correlated(r=-0.666, P<0.01), and the expressions of Ki-67 and p27 were negatively correlated with p27 in patients with acute leukemia (r=-0.316, P<0.05).Conclusion The evaluation of expression of Ki-67, VEGF and p27 on acute leukemic cells provides new insights to the pathogenesis is helpful in mechanism and is helpful in the diagnosis of acute leukemia.

BACKGROUND: There has been increasing attention in the study of adolescent idiopathic scoliosis (ALS)and bone metabolism, which is accompanied by osteopenia and osteoporosis. Interleukin(IL) -6, a cytokine that strongly promotes bone resorption, participates in the regulation of bone metablism.OBJECTIVE: To explore the relationship between changes of bone mineral density(BMD) and serum IL-6 content in AIS.DESIGN: A controlled non-randomized concurrent study involving patients with AIS and and healthy volunteers.SETTING: The clinic and wards of the department of spinal surgery of a university-affiliated hospital.PARTICIPANTS: Thirty-six patients with AIS(6 males and 30 females aged 12 to 18 years) were treated in the Department of Spinal Surgery, Drum Tower Hospital, Medical College of Nanjing University from July to October 2003, who had a Cobb angle ranging from 34° - 109° and curvature of the thoracic spine. Thirty-six healthy adolescent volunteers(7 males and 29 females within the range of 13 - 18 years old) served as the control group.METHODS: The BMD was measured at L2- L4 and the proximal femur;(including the femoral neck, greater trochanter and Ward' s triangle) by dual-energy X-ray absorptiometry and serum IL-6 determined by enzyme-linked immunosorbent assay(ELISA).MAIN OUTCOME MEASURES: ① BMD of the lumbar spine and femur ② Comparison of serum IL-6 content of all the subjects.RESULTS: The BMD of AIS patients at L2- L4, femoral neck, greater trochanter and Ward' s triangle was 0.79±0. 12, 0.78±0. 12, 0.65± 0. 10, and 0. 69 ± 0. 13 g/cm2, respectively, all significantly lower than the corresponding measurements of the control group(1.09 ± 0. 11, 0.95 ± 0. 11,0. 78 ± 0. 10, and 0. 88 ± 0. 11 g/cm2, respectively, P ＜ 0. 001), whereas the serum IL-6 content in the patients was significantly higher than that in the control subjects ( P ＜ 0. 005). The changes of BMD at the lumbar spine and the three sites of femur were negatively correlated with serum IL-6 in AIS patients( P ＜ 0. 001 ), but not so in the control group( P ＞ 0.05).CONCLUSION: The BMD is decreased and serum IL-6 elevated in patients with AIS, and excessive secretion of IL-6 might be one of the important factors of osteopenia in AIS.

Objective To study the protective effects of nitroxides against hu man keratinocytes oxidative damage induced by H2O2 and its possible mechanisms. Methods Normal human keratinocyte cultures obtained from foreskin were served as test-system. Human keratinocytes were cultured in human keratinocytes growth m edia (KGM) without serum and supplemented with 0.1 mmol/L Ca2+. Experiments wer e performed in culture when the cells grew to fuse. Oxidative damage was induced by adding H2O2 directly to the culture media at different concentrations in the present and absence of nitroxides [(2, 2, 6, 6-tetramethylpiperidine (TEMPO) a nd 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine (TEMPOL)]. The cell viability w as monitored and the intracellular level of reduced glutathione (GSH), the activ ities of glutathione-peroxidase(GSH-Px), superoxide dismutase (SOD), and catal ase were evaluated. Results ①H2O2 could cause damage to human keratinocytes dir ectly. There was a significantly negative correlation between H2O2 concentration and cell viability. ②The level of GSH in keratinocytes lowered with treatment of H2O2. The activities of GSH-Px, SOD and catalase decreased. ③Pretreatment o f the cells with TEMPO and TEMPOL inhibited the damaging effects of H2O2 on cell viability and on cell antioxidant enzymatic systems. Conclusion The results of the study suggest that nitroxides may provide protection for cultured human kera tinocytes against H2O2-induced oxidative injury. It is proposed that the effec ts of nitroxides against cell oxidative damage be related to their protection of cellular enzymatic activities and maintaining cellular antioxidant systems.

Objective To investigate the therapeutic effects and side effects of FLAG and MEA regimen in the treatment of relapsed and refractory adult acute myeloid leukemia.Methods Use retrospective analysis to Observe the therapeutic effects and side effects of the 51 cases of relapsed and refractory adult acute myeloid leukemia (M3 except) from January 2009 to June 2012 in our hospital,which are divided into FLAG group (23 cases) and MEA group (28 cases) according to chemotherapy.Results In FLAG group,the rate of complete remission was 30.4 ％ (7/23),the rate of partial remission was 17.4 ％ (4/23),the effective rate was 47.8 ％ (11/23).In MEA group,the rate of complete remission was 35.7 ％ (10/28),the rate of partial remission was 21.4 ％ (6/28),the effective rate was 57.1％ (16/28),difference between two groups was not statistically significant. Both groups appeared Ⅳ degrees myelosupression,and there were no significant differences between them on incidences of secondary infection [95.7 ％ (22/23) vs 89.3 ％ (25/28)] and haemorrhagia [82.6 ％ (19/23) vs 85.7 ％ (24/28)].Difference on cardiac toxicity was statistically significant.Conclusions Compared with MEA regimen, FLAG regimen are similar effective and can be well tolerated,which has lower cardiac toxicity. Thus, FLAG regimen can be used as first-line treatment for relapsed and refractory adult acute myeloid leukemia.