Objective To study the effect of γ-rays irradiation on the differentiation potential of the human peripheral blood monocytes (PBMCs) into osteoclast-like cells (OCLs) in vitro.Methods PBMCs were isolated by density gradient centrifugation,treated by receptor activator of nuclear factor-κ B ligand (RANKL) and macrophage-colony stimulating factor (M-CSF) and exposed to 137Cs γ-rays with different radiation doses (0,0.75,2 Gy).After seven days of incubation,the cells were stained for tartrate resistant acid phosphatase (TRAP) and bone slices were stained by toluidine blue on the tenth day.Meanwhile,the characteristic osteoclast markers including Cathepsin K and integrin β3 were analyzed by real-time PCR.Tartrate resistant acid phosphatase 5b (TRAcP-5b) in the culture supernatant wasdetermined by ELISA.Results PBMCs were differentiated into OCLs by the treatments of RANKL and MCSF.The number of TRAP positive multinucleated OCLs was significantly higher in the dose of 0.75 Gy group than in control (0 Gy) group (t =3.451,P ＜ 0.05).Compared with the control group,the expression levels of Cathepsin K and integrin β3 and the concentration of TRAcP-5b were significantly elevated (t =2.343,2.728,3.631,P ＜ 0.05).However,in the 2 Gy group,there was a decrease in the number of osteoclasts,mRNA expression level of osteoclast characteristic markers and TRAcP-Sb,but no statistically significant differences compared with the control group.Conclusions Ionizing radiation may influence the osteoclastogenesis during the PBMCs differentiation to OCLs.At low dosage,ionizing radiation promotes osteoclastogenesis and enhances the resorptive activity of osteoclasts,but a decline of differentiation potential was observed at high dosage of radiation.

BACKGROUND: Human umbilical cord mesenchymal stem cells play a vital role in the repair of the blood-brain barrier after traumatic brain injury. OBJECTIVE: To investigate the protective effect of human umbilical cord blood mesenchymal stem cell transplantation on the blood-brain barrier after traumatic brain injury in rats and its possible mechanism. METHODS: Sixty Sprague-Dawley rats were randomly divided into sham operation group, injury control group (model group), cell transplantation group and Sunitinib group, with 15 rats in each group. Traumatic brain injury model was established by improved hydraulic impact method in all the groups except for the sham operation group. Rats in the sham operation group and model group were injected with 1 mL of normal saline, and those in the cell transplantation group were injected with 1 mL of 2×109/L human umbilical cord blood mesenchymal stem cells. The injection was done via the tail vein at 0.5, 24, and 48 hours after modeling. In the Sunitinib inhibitor group, the rats were given oral PDGFR-β pathway inhibitor, Sunitinib (80 mg/kg), from 1 day before modeling until being executed. Three days after modeling, the water content in brain tissue was measured by dry-wet specific gravity method, the permeability of the blood-brain barrier was measured by Evans blue method, expression of GFAP and vWF was observed by immunofluorescence staining and the expression of blood-brain barrier related proteins and PDGFR-β pathway proteins was detected by western blot method. RESULTS AND CONCLUSION: Compared with the sham operation group, the brain water content of the model group increased significantly (P < 0.05), while that of the cell transplantation group was significantly lower than that of the model group (P < 0.05). The Evans blue content in the model group was significantly higher than that in the sham operation group (P < 0.05), while the Evans blue content in the cell transplantation group was significantly lower than that in the model group (P < 0.05). Compared with the sham operation group, the expression of vWF and GFAP increased significantly in the model group (P < 0.05), while compared with the model group, the expression was significantly reduced in the cell transplantation group (P < 0.05). Western blot showed that ZO-1, Oclaudin-5, and PDGFR-β protein expressions in the model group were significantly lower than those in the sham operation group (P < 0.05), while these expressions were significantly increased in the cell transplantation group as compared with the model group (P < 0.05). To conclude, intravenous injection of human umbilical cord mesenchymal stem cells through the tail ein can reduce the permeability of blood-brain barrier and play a neuroprotective role in rats with traumatic brain injury. Its possible mechanism is related to the promotion of PDGFR-β expression in the injured area.

Objective To explore the feasibility of using glycophorin A somatic mutation in peripheral erythrocytes,in order to evaluate the cancer risk of occupational medical exposure to ionizing radiation.Methods Totally 336 medical radiation workers were recruited as three groups (general radiation group,computer tomography group,intervention and radiation treatment group) and 112 healthy adults were selected as control by using stratified random cluster sampling method,where 176 medicalradiation workers and 58 health controls had a MN-heterozygous type.The erythrocytes were fixed and bound with fluorescent-labeled monoclonal antibody,and the glycophorin A somatic mutation frequency was assayed by a modified BR6-1W1 method using a FACScan flow cytometer.The individual susceptibility to radiation was investigated using micronuclei test and 3-Aminobenzamide index test.Results The GPA somatic mutation frequency of medical-radiation workers was significantly higher than that of healthy control ( t =2.29 - 11.48,P ＜ 0.05 ).In particular,the NO GPA aberration frequency of interventional radiology workers was much higher than that of the general medical diagnostic workers (t =2.01,P ＜ 0.05).In addition,the NO GPA variant frequency changed significantly with the years of radiation service,cumulative doses,and 3AB index.However,the NN GPA variant frequency was only associated with the years of radiation service,and no significant correlations were found between NN GPA variant frequency and cumulative dose of radiation exposure or 3AB index. Conclusions GPA mutation frequency,especially NO GPA mutation frequency could be used as a sensitive biomarker to predict the DNA damage and individual susceptibility for the population exposed to professional low-dose ionizing radiation.

Objective To investigate the clinical value of nutritional risk screening 2002(NRS2002)and malnutritional universal screening tools(MUST)in the preoperative nutrition risk evaluation of patients with gastric cancer.Methods The preoperative nutritional risk of 3 14 patients who had been admitted to the Third Affiliated Hospital of Sun Yat-sen University from January 2004 to December 2007 was assessed by subjective global assessment(SGA),NRS 2002 and M UST,and the influence of nutritional risk on the incidence of postoperative complications and hospital stay was investigated.All data were analyzed by Wilcoxon test,Kappa test and Logistics regression analysis.Results Compared with SGA,the sensitivity,specificity,positive predicting value and negative predicting value were 86.7%,74.2%,86.9% and 73.8% for NRS2002,and were 73.1%,70.6%,74.8% and 68.7% for MUST.Compared with MUST,NRS2002 had a higher consistency with SGA(K_(NRS2002)=0.601,K_(MUST)=0.436).Logistic regression analysis revealed that patients with higher MUST or NRS2002 score had higher incidence of postoperative complications and longer hospital stay.In the aspect of hospital stay,the relative risk of MUST was 2.517,which was lower than 3.426 of NRS2002.The relative risk of MUST was 0.529,which was lower than 0.642 of NRS2002 in the aspect of incidence of postoperative complications.Conclusions NRS2002 and MUST are suitable for preoperative nutritional risk screening of patients with gastric cancer,and the score of NRS2002 or MUST is associated with the incidence of postoperative complications and length of hospital stay.However,NRS2002 is more accurate than MUST in the reflection of nutritional risk of patients with gastric cancer.

Objective To investigate the effects of laporoscopic resection applied to colorectal cancer patients on metabolism. Methods According to patients' choice of operation, either laparoscopic-assisted (n = 22, experimental group) or open(n = 27, control group) resection of colorectal cancer was performed. The levels of electrolyte were assayed preoperatively, postoperatively and on the time of 24 hours after opera-tion. Rseults There was no significant difference in the level of electrolyte before operation between the two groups (P > 0. 05). Compared with the preoperative period, the level of serum potassium in the both groups were significantly increased after operation(P < 0. 05), and 24 hours later, the levels of electrolyte was not significantly different in both the two groups (P > 0. 05). During the postoperative period, the level of serum potassium in the experimental group was lower than the control group(P <0. 05), while the level of HCO_3~- was higher than the control group(P <0. 05), and there were no significant differences in the level of serum sodium, chloride and calcium between the two groups(P > 0. 05). Conclusions Laparoscopic-assisted re-section of colorectal cancer gives lower levels of stress responses compared to open surgery. However, it shows higher effect on the level of HCO_3~- , and must be paid more attention during operative and postopera-tive period.

Objective To evaluate the preoperative nutritional status of patients with gastric carcinoma by using the European Nutritional Risk Screening 2002(NRS 2002)and its prediction for postoperative nutrition-related complications.Methods We prospectively evaluated the nutritional risk of 314 gastric cancer patients admitted in one center from 2004 to 2007 with NRS 2002 with China's normal body mass index(BMI),in terms of postoperative complications,mortality and hospital stay.Results NRS 2002 scoring system was applicable in 93.1% cases.Preoperatively 125 patients were of score≥3,accounting for 39.8% of this group.The postoperative complication rate(26.2%)was higher than 13.8% in those with normal preoperative nutritional scores(NRS 2002 score＜3)(P＜0.05);The odds ratio to develop a complication was 0.642 in patients with preoperative nutritional risk score(P＜0.05),and 1.596 in patients with clinicopathological stage of gastric cancer(P＜0.01).The correlation between length of hospital stay and nutritional risk was also assessed by Pearson correlation analysis.The Pearson coefficient was 0.177(P=0.002).Conclusion Preoperative nutrition score(NRS 2002)≥3 predicts higher postoperative complications and longer hospital stay.Preoperative nutritional support is necessary in patients with preoperative nutrition score(NRS 2002)≥3.

Objective To explore the effects of delayed mild hypothermia (MHT) in different time windows on the expressions of Bcl-2, Bax and Caspase-3 in brain tissue of model rats with traumatic brain injury (TBI). Methods Thirty-six clean adult male SD rats were randomly divided into NT group (normal temperature), MHT 15 min group, MHT 2 h group and MHT 4 h group. TBI rat model was established by electronical controlled cortical injury device. The rats in the NT group were treated with normothermia (37℃) and the rats in the three hypothermia groups were implemented with low temperature (33.0±1.0)℃at 15 min, 2 h and 4 h for 6 h respectively after establishment of TBI model. The modified neurological senerity scores (mNSS), morphological changes in hippocampal CA1 areas, immunohistochemical staining and Western blot assay for Bcl-2, Bax and Caspase-3 were compared 3 days after TBI between the four groups. Results The neurological behavioral deficits were found in each group. Compared with the NT group, the mNSS were decreased in the three hypothermia groups (P<0.01). The results of HE staining showed that the structure of neurons was regular and arranged neatly, and the number of neurons decreased with alleviated nuclear fragmentation and dissolution in hypothermia groups. Compared with the NT group, the expression of Bcl-2 was upregulated, and the expressions of Bax and Caspase-3 were downregulated in three hypothermia groups (P<0.05). The above experimental results were superior in MHT15 min group to MHT 2 h group, and the therapeutic effect in MHT 2 h group was similar to MHT 4 h group. Conclusion The proper delayed mild hypothermia treatment could inhibit neuronal apoptosis and alleviate brain damage.

Objective To explore the effect of atorvastatin on the proliferation and apoptosis of K562 cells andto investigate its mechanisms.Methods The cells were treated by different concentrations of atorvastatin.The CCK-8 assay was employed to detect the cell proliferation.The cell apoptosis was detected by AnnexinV-FITC/PI dual staining;the flow cytometry was used to detect the cellular cycle;the activities of caspase-3,-8,-9 were detected by the colorimetric method;qRT-PCR was employed to measure the mRNA expression levels of Bcl-2 and PDCD5 in K562 cells.Results Atorvastatin could inhibit the proliferation of K562 cells in a time-and dose-dependent manner(P＜0.05);and induced the apoptosis of K562 cells,the percentage of G0/G1 phase cells was increased after atorvastatin treating k562 cells(P＜0.01),while the percentage of S phase cells was decreased(P＜0.01),moreover which showing the concentration dependence(P＜0.01);atorvastatin activated the caspase-3,-8,-9 (P＜0.01);down-regulated Bcl-2 mRNA expression and up-regulated PDCD5 mRNA expressionin a concentration dependence(P＜0.01).Conclusion Atorvastatin can inhibit the proliferation and induce apoptosis in K562 cells.

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