Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major pathogens of the hospital infection.Its clinical features and drug-resisetance situations have always been concerned.But since the late 1990s,another class of MRSA has become a major concern worldwide as an emerging pathogen in the community.This new class of MRSA is called community-acquired MRSA (CA-MRSA).With the rapid development of the infection of CA-MRSA in 20 years,especially in the latest 3 years,CA-MRSA may be replacing the hospital-acquired MRSA strains(HA-MRSA) as one of the major pathogens in the hospital and the community as well.The characteristics of CA-MRSA are very different from those of HA-MRSA.This review summarizes the current studies of CA-MRSA on the epidemiology and the molecular characteristics.

Objective To study the effect of vitamin D3 on breast cancer xenografted on a nude mouse model. MethodBalb/c nude mouse was injected subcutaneously with 10 6 human breast cancer cell line MCF-7.Two thousand units Vitamin D3 was administered in mice i?m every the other day. Tamoxifen (5 mg/kg) was fed per mouse daily. Mice were divided into four groups with ten mice in each group: Vitamin D3 group, Vitamin D3 and tamoxifen group, tamoxifen group and control group. After 4 weeks, mice were killed to measure volume of tumor and calcium and phosphorus levels in serum. Tumor cells were analyzed with flow cytometery to detect apoptosis and cell cycle. Results Calcium levels in serum of mice treated with vitamin D3 were higher than that of other two groups, but phosphorus levels in serum were lower . Apoptosis rate was higher than that of control group and tumor cells were arrested in G0/G1 phase, especially those treated with vitamin D3 and tamoxifen. ConclusionsVitamin D3 could significantly induce apoptosis of breast cancer cells and arrest tumor cells in G0/G1 phase. It is synergic with tamoxifen and this may have clinical significance in the treatment of breast cancer.

AIM: To observe the effect of Jianpixiaoshi Pill (Rhizoma Atractylodis Macrocephalae, Fructus Aurantii Immaturus, Radix Aucklandiae, etc.) METHODS: We conducted the humoral immunity test, intestine peristal sis test, gastric emptying test, gastric analysis test on rat's and mouse's mode ls of splee n weak by oral administration of Rhubarb root lard and cabbag e, respectively. RESULTS: On mice fed on Rhubarb root, Jianpixiaoshi i Pill can effectively potentiate immunity, improve the velocity of stomach and intestine, expedite the advance speed of ink in the small intestine and the velo city of gastric emptying, reduce the residual rate of methyl orange in stomach. On rats fed on lard and cabbage, J ianpixiaoshi Pill can gain mouse's weight improved, increase the total acidity of the gastric juice and the activity of pepsin. CONCLUSION: Jiah pixiaoship Pill has remarkable effect on improvin g the function of intestine and stomach.

Objective To compare the time course of distribution and elimination of gelatin and lactated Ringer's solution (LR) by volume kinetics and mass balance analysis during hemorrhagic shock in dogs, and try to design and optimize fluid therapy in a more scientific manner. Methods Twenty dogs were randomly divided into 4 groups: CL group, CG group, BL group, and BG group. Each animal was subjected to two randomly ordered experiments that separated for at least 1 week. In the first phase, plasma volume expansion was studied in the state of anesthesia, animals received 30 mL/kg of LR (CL group) or 10 mL/kg of gelatin (CG group) over 30 min. In the second phase, plasma volume expansion was studied in the state of hemorrhagic shock, animals received 30 mL/kg of LR (BL group) or 10 mL/kg of gelatin (BG group) over 30 min. Hb concentration and Hct were measured every 5 min during and after infusion for 90 min. Hemodynamic parameters were recorded at the same time. The distribution and elimination of infused fluid were studied by volume kinetics, based on serial analysis of hemoglobin dilution in arterial blood, and by mass balance that incorporated volume calculations derived from volume kinetic analysis and measurements of urinary volumes. Results When a one-volume kinetic model was fitted to the data, the value of V and Kr in CG, BL, and BG group were significantly smaller than those in CL group (P<0.05), which could be found from the computer-generated curves.When a two-volume kinetic model was fitted to the data, the value of V1, Kr, Kt in BL group were significantly smaller than those in CL group (P<0.05). The calculations based on mass balance corresponded to the predicted based on volume kinetics. The change of central volume (CCV) in BL, BG, and CG group was significantly greater than those in CL group (P<0.05). The VEE in BG and CG group was significantly higher than that in BL and CL group. The value of VEE in BL group was significantly higher than that in CL group (P<0.05). Conclusions Both of the efficacy of lactated Ringer's solution and gelatin increased significantly in the state of hemorrhagic shock, and the former increased more.

Objective To observe rosiglitazone(RSG) combined with insulin therapy in type 2 diabetes pa-tients with tuberculosis. Methods 66 cases with type 2 diabetes and tuberculosis used the conventional antitubercu-losis treatment, divided into insulin group(DM + INS) 33 cases, the treatment group (DM + INS + RSG) 33 with dy-namic observation of blood glucose, and the lesions of tuberculosis in sputum culture. Results DM + INS + RSG group at the same time as the conversion rate is higher than DM + INS group(X2 = 8.45, X2 = 6.11,X2 = 12.87, P<0.05), the lesions were closed and empty absorption were significantly different (X2 = 15.60, P < 0.05 ; X2 = 5.00, P< 0.05), DM + INS group before and after treatment did not change significantly. After treatment DM + INS + RSGgroup FPG, PPG and HbAlc levels lower than before treatment(P < 0.05～0.01 ) and DM + INS group with sig-nificant differences( P < 0.05～0.01 ). Conclusion The addition of rosiglitazone to insulin treatment results in sig-nificantly improvement in glycemic control in the type 2 diabetic patients.

Background Radiation-induced optic neuropathy (RION) is a severe complication after radiotherapy for head and neck cancer,which threatens the visual acuity and quality of life of patients.Till now,there is no recognized treatment for RION.It is of great significance to study the natural progression of the RION,and to prevent and treat RION.Objective This study was to establish an ideal radioactive optic nerve injury animal model.Methods Healthy 8-week SD rats with hygiene grade were randomly divided into normal control group and model group,with 6 rats in each group.The total 30 Gy dose of radiation with 3 portions was used to irradiate the head model group rats;ELISA was performed to analysis the changes of endothelin-1 (ET-1) and Von Willebrand factor (vWF) concentrations in blood 2,4 and 8 weeks after irradiation.Hematoxylin-eosin staining and transmission electron microscope were performed to observe the changes of optic structure.The use and care of the experimental animals complied with the ARVO statement.Results The concentrations of ET-1 in the model group were (23.18± 0.11),(27.98 ±0.22),(33.90 ±0.1 1),(65.25 ±0.38) and (43.82 ± 0.09) pg/ml before irradiation,1 day,2,4,6 weeks after irradiation,those in the normal control group were (22.65 ± 0.14),(23.18 ± 0.19),(23.68 ± 0.15),(24.23±0.12) and (23.58±0.16)pg/ml.The concentrations of vWF in the model group were (63.16±2.21),(88.32± 2.06),(123.38 ± 1.36),(191.40 ± 0.61) and (141.69 ± 0.82) pg/ml before irradiation,1 day,2,4,6 weeks after irradiation,those in the normal control group were (62.82 ± 1.56),(63.35 ±2.06),(64.12 ± 1.76),(63.52±2.02) and (63.48 ± 1.55)pg/ml.There were significant differences of ET-1 and vWF concentrations among different groups and time points (ET-1:Fgroup =32.160,P =0.012;Ftime =21.180,P =0.023.vWF:Fgroup =73.110,P=0.001;Ftime =46.180,P =0.002).The nerve fiber bundles was swelled with disordered arrangement and vacuolization 8 weeks after irradiation.Axon swell and atrophy,axons with myelin sheath layer plate separation were obtained.The rates of axon demyelination in the normal control group and model group were (1.35 ±0.79) ％ and (14.44±2.32)％,respectively.There was a statistically significant difference between the two groups (t =14.07,P＜0.01).Conclusions The total 30 Gy dose of radiation on the head of rats can make stable radioactive optic nerve injury model.This model making method is simple,cheap and practical,which is worth further study.

Objective To evaluate the effect of dexmedetomidine on the inflammatory responses in brain tissues in septic rats.Methods Seventy-two male Sprague-Dawley rats,aged 10 weeks,weighing 250-280 g,were randomly divided into 4 groups (n =18 each):control group (group C); sepsis group (group lipopolysaccharide (LPS)) ; distilled water group (group DW) and dexmedetomidine group (group D).Sepsis was induced by intraperitoneal injection of LPS 5 mg/kg (dissolved in normal saline 1 ml) in groups LPS,DW and DEX,while normal saline 1 ml was injected intraperitoneally in group C.Distilled water 20 μl was injected into the lateral cerebral ventricle in group DW,while dexmedetomidine 3 μg/kg (dissolved in distilled water 20μl) was injected into the lateral cerebral ventricle in group DEX.Six animals were sacrificed at 1,2 and 6 h after administration and hippocampi were removed for determination of TNF-α and IL-6 contents (by ELISA) and TLR4 mRNA expression in hippocampal tissues (by RT-PCR).Results Compared with group C,TNF-α and IL-6 contents in hippocampus tissues were significantly increased at each time point after administration in group LPS (P ＜ 0.05).Compared with group LPS,no significant change was found in TNF-α and IL-6 contents in hippocampal tissues (P ＞ 0.05),and TLR4 mRNA expression was significantly up-regulated at each time point after administration in group DW (P ＜ 0.05).Compared with group DW,TNF-α and IL-6 contents in hippocampal tissues were significantly decreased at each time point after administration,and TLR4 mRNA expression was significantly up-regulated at 2 and 6 h after administration in group DEX (P ＜ 0.05).Conclusion Dexmedetomidine can reduce inflammatory responses in brain tissues in septic rats via down-regulating TLR-4 mRNA expression.

Objective To explore the role of p16 gene methylation in fibroblasts in the occurrence and development of keloid.Methods Skin tissue specimens were resected from the lesions of patients with keloid and normal skin of healthy human controls.Fibroblasts were isolated from these tissue specimens and subjected a primary culture.An immunohistochemical analysis was performed to measure the expression of p16 protein in tissue specimens,real-time fluorescence-based quantitative PCR to determine the mRNA expression level (expressed as 2-△△Ct) of p 16 and DNA methyltransferases (DNMTs) in fibmblasts,and bisulfite sequencing PCR (BSP) to estimate the methylation status of p16 gene in the tissue specimens and primary fibroblasts.Results The keloid fibroblasts (KFbs) showed significandy lower mRNA expression of p16 gene (0.64 ± 0.18 vs.1.92 ± 0.23,t =10.54,P＜ 0.05),but significantly higher mRNA expressions of 3 DNMTs (DNMT1:2.58 ± 0.23 vs.1.13 ± 0.21,t =11.22,P ＜ 0.05; DNMT3A:4.87 ± 0.46 vs.2.38 ± 0.32,t =10.81,P＜ 0.05; DNMT3B:1.57 ± 0.12 vs.0.57 ± 0.16,t =12.45,P＜ 0.05) compared with the normal fibmblasts (NFbs).The DNA methylation rate in the p16 gene promoter region was significantly increased in keloid tissue (1.81％ ± 0.46％) and KFbs (3.15％ ± 0.94％) compared with normal skin tissue (0.90％ ± 0.35％,F =14.23,P＜ 0.01) and NFbs (0.17％ ± 0.29％,F=37.62,P＜ 0.01).Conclusions The methylation and low expression of p16 gene in KFbs may be associated with the uncontrolled growth of keloid,and DNMTs may play a role in the pathogenesis of keloid.

Objective To observe the changes of cell cycle on cancer cells after dihydroartemisinin and X-ray irradiation. Methods Human HeLa cells of cervical cancer with p53 mutation was used and human SiHa cells of cervical cancer with wild p53 was used as control. Flow cytometry was used to detect the effect of dihydroartemisinin (20 and 100 μmol/L) and irradiation (6 Gy)on cell cycle. Western blot was used to measure the levels of cell cycle protein. Results G2 arrest was observed in irradiated HeLa cells, which the proportion of cells in G2 phase was increased from 14.45% to 73. 58% after 6 Gy X-ray irradiation, but it was abrogated by dihydroartemisinin from 73. 58% to 48.31%in HeLa cells, and it had no change on the SiHa cells. The elevated Weel protein and the lowered Cyclin B1 protein were observed with the G2 arrest severity. The expression of radiation-induced Weel protein was suppressed and the Cyclin B1 protein was increased after dihydroartemisinin treatment, which was in accordance with the abrogation of radiation-induced G2 delay. Conclusions The main effect of irradiation on cell cycle of p53 mutated HeLa cells is G2 arrest. Dihydroartemisinin could abrogate it, which is associated with the changes of Weel protein and Cyclin B1 protein. In Siha cells, the main effect of irradiation on cell cycle is G1 arrest, and dihydroartemisinin has no effect on it.

Objective To construct targeted ultrasound contrast agent carried goat anti-mouse IgG antibody (UCA-IgG) and evaluate the effectiveness of its targeted adhesion using parallel plate flow chamber. Methods The ultrasound contrast agent targeted to mouse IgG was designed by conjugating monoclonal antibodies against mouse lgG to the lipid monolayer shell of the agent using biotin-streptavidin. The binding of IgG antibodies to the ultrasound contrast agent were identified by fluorescence in vitro. The attachment and detachment of UCA-IgG to mouse IgG immobilized on a culture dish were assessed in a parallel-plate flow chamber. While the plate lacked mouse IgG,or blocked with large number of goat anti-mouse IgG were served as two control groups. Results UCA-IgG issued a bright green fluorescence, while the contral lipid ultrasound contrast agent didn't show fluorescence. The number of UCA-IgG bound to mouse IgG of experimental group was greater than two control groups,increased with increasing coverslips surface antibody concentrations (P<0. 05),and there was significant positive correlation between the number of UCA-IgG bound to mouse IgG and time of combination (P<0.05). The adhesion rate of experimental group increased with shear stress before 0. 5×10-5 N/cm2 (P<0.05) and then decreased (P<0. 05). There was limited adherence of control groups to the UCA-IgG. The stess of half-maximal detachment was increased with increasing coverslips surface antibody concentrations (P<0.05). Conclusions UCA-IgG could adhere to mouse IgG in the physical conditions. It may provide strong supports for studying other targeted ultrasound contrast agent preliminary and fatherly in vitro.