OBJECTIVETo improve the method for monitoring sleep state and respiratory rhythm of SD rats, providing a solution for rats' chewing on the wires, signal loss and instability problems in the animal model of sleep apnea syndrome (SAS).

METHODSWe improved monitoring electrodes of both electrocorticogram (ECoG) and electromyogram (EMG), signal circuit and animal operation.

RESULTSOperation time was shortened and wound exposure time was reduced, which made it easier for postoperative recovery. The ECoG and EMG signals were more stable with sharp image, and signal circuit lines had better conductivity and material durability, achieving continuous monitoring for a long time and high success rate. We could precisely distinguish the sleep wake state and the sleep apnea events in rats according to these signals.

CONCLUSIONThe improved method is more reliable and practical to test the small animal model of SAS, and is more easily to operate and the signals are more stable.

Animals ; Electroencephalography ; methods ; Electromyography ; methods ; Models, Animal ; Monitoring, Physiologic ; methods ; Rats ; Respiration ; Sleep ; Sleep Apnea Syndromes ; diagnosis

OBJECTIVETo study the effects of aluminum citrate (AC), rare earth compounds (REC) and sodium selenite (SS) on the surface elements of chrysotile fibers and the inhibitory mechanisms of three compounds for chrysotile-induced biological activities.

METHODSAfter being soaked in 250, 500 and 1000 microg/ml aluminum citrate solutions, 125, 250, 500 and 1000 microg/ml mixed rare earths solutions or 125, 250, 500 and 1000 microg/ml sodium selenite solutions for 10 min or 1 hour, the fabrication and the levels of surface elements of chrysotile fibers were determined.

RESULTSAluminum citrate, mixed rare earths or sodium selenite all could be adsorbed by chrysotile fibers. After pretreatment of chrysotile fibers with aluminum citrate, mixed rare earths or sodium selenite solutions for 10 min or 1 hour, the corresponding elements or ion on the surface of chrysotile fibers increased with the increase of concentration of the solutions.

CONCLUSIONPretreatment of chrysotile with aluminum citrate, mixed rare earths or sodium selenite solutions can change the fabrication and the levels of surface elements of chrysotile fibers, and inhibit the biological activities of chrysotile by "sealing" some "active sites" on the surface of chrysotile fibers.

Asbestos, Serpentine ; chemistry ; toxicity ; Citric Acid ; chemistry ; Metals, Rare Earth ; chemistry ; Sodium Selenite ; chemistry

Alfimeprase(ALF)is a recombinantly modified variant of non-hemorrhagic zinc metalloproteinase fibrolase.The target gene alf was obtained from the clone vector p43-alf and cloned into the Pichia pastoris expression vector pPICZ? A.Through high efficiency transformation and Zeocin selection,the recombinant strains of pPICZ?A-alf /GS115 were isolated.In order to achieve a high level expression of recombinant Alfimeprase(rALF),optimization of pH value,methanol daily addition concentration,cell density and methanol induction time points were carried out,and the production of rALF reached up to 425 mg/L.By His?Bind chromatography,the purity of secreted rALF was as high as 95 %.SDS-PAGE and Western blot analysis show that rALF has a molecular weight of about 24 kDa and is bound specifically to anti-His?tag monoclonal antibody.Activity identification results of the modified fibrin plate method demonstrate that the secreted rALF has high fibrinolytic activity.Thus sets up an optimized expression system for ALF,which will play an important role in its further studies and industrial production.

Objective To study the structure of class 1 integrons in 90 strains of Pseudomonas aeruginosa isolated during two periods of 1992-1996 and 2003-2005,and to get information about the structure changing of class 1 integrons by comparing their structures in two different periods.Methods Routine PCR and long PCR were performed to amplify the class 1 integrons and the gene cassettes they carried, followed with sequencing and blast via GenBank.Results Thirteen out of 41 strians ioslated during the period of 1992-1996 were positive on class 1 intergrons.Long PCR showed that the class 1 integron was 1868 bp in length and contained 2 resistance genes averagely.Six types of resistance genes of qacEA1 (n=6), sull (n=14),aadA1 (n=2),aadB (n=1),PSE-1 (n=2) and tetA (n=1) were found in these integrons, which consisted of 5 patterns of resistance cassette arrangements.Nineteen strains were proved to carry class 1 integrons in 49 isolates from 2003-2005.The mean DNA sequence length of them was 3383 bp with 3.6 resistant genes in averagely,10 types of resistance genes,qacEA1 (n=18),sull (n=25),aadA1 (n=6), aadB (n=7),aacA4 (n=2),PSE-1 (n=3),VEB-1 (n=4),OXA10 (n=1),cm1 A (n=1) and tetA (n =2),were identified in these integrons,which were composed of 9 patterns of resistance cassette arrangements.Conclusion In terms of produce length and resistance cassettes carried in the integrons, greater complexity is found in the structure of class 1 integrons in strains isolated during 2003-2005 than those during 1992-1996.

Objective This study was purposed to analyze and summarize the vein temporary cardiac pacing therapy in patients with acute inferior wall myocardial infarction complicated by high degree atrioventricular block (AVB) . Methods One hundred and twelve patients with acute inferior wall myocardial infarction complicated by high degree AVB were selected as observation and research subjects, and they were treated by vein temporary cardiac pacing therapy. The safety, availability of different kinds of this surgical methods and the relationship between these surgical methods and complication were observed. Results Three out of 60 patients who were treated by ordinary temporary pacing electrode catheter were suffering from cardiac tamponade. No serious complications occurred when 52 patients were treated by floating temporary pacing electrode catheter. Conclusion Floating temporary pacing electrode catheter have already proved safe and effective in the treatment of acute inferior wall myocardial infarction complicated by AVB, and it could decrease the incidence of serious complications such as myocardial perforation.

Objective To analyze and summarize the treatment strategies for unstable angina with no-reflow phenomenon after PTCA during early percutaneous interventional procedures.Methods A total of 32 cases with unstable angina were divided into two groups:one group with drug therapy and the other group with drug therapy and thrombus aspiration catheter.The patients were chosen when there was no-reflow phenomenon after PTCA during early percutaneous interventional procedures and their clinical data were compared and analyzed.Blood flow TIMI grade,myocardial perfusion grade (MBG),TIMI myocardial perfusion (TMP) grade and other indexes were observed and recorded.Results The general conditions had no statistical difference between two groups.Compared with the drug therapy group,the proportion of patients with TIMI,MBG and TMP grade 3 was higher in aspiration and drug therapy group (89％ VS 71％ P＜0.05).Conclusion Drug therapy and thrombus aspiration catheter in treatment helps to improve myocardial perfusion level for unstable angina with no no-reflow phenomenon after PTCA during early percutaneous interventional procedures.

Objective To observe the expression of fibronectin in bone of fluorosis rats and in vitro cultured osteoblast,and to study the role of fibronectin in pathogenesis of chronic fluorosis.Methods Male and female Wistar rats 144 were randomly divided into four groups,which were designated as the control group(normal diets,n =36),fluoride group(normal diets + 100 mg/L fluoride,n =36),lower calcium monophagia group (synthetic diets,n =36) and lower calcium monOphagia with fluoride group(synthetic diets + 100 mg/L fluoride,n =36).Rats were sacrificed 4 and 8 months after beginning of the experiment,respectively,and femur tissue was fixated and paraffin-embedded.The osteoblast isolated from calvaria of neonatal rats was treated with different dose of fluoride(0,1,2,4 mg/L fluoride,respectively) for 48 and 72 h,cell culture supernatant and cells were collected,respectively.The cranial osteoblasts were cultured in vitro and divided into four groups according to different concentration of fluoride added,which were 0(control group),0.01,1.00,and 10.00 mg/L groups.These cells were treated with mineralized induced medium at day 2 and cultured for 3 more weeks whereafter,and then the slides were fixed in alcohol.The expression of fibronectin in rat femur tissue was detected by immunohistochemistry (IHC),and fibronectin mRNA expression was determined by in situ hybridization; the fibronectin levels in supernatant of cultured osteoblast was examined by enzyme-linked immunosorbent assay(ELISA),and the expression of fibronectin mRNA in osteoblasts was detected with RT-PCR; skull mineralized nodule formation of osteoblasts was observed under a light microscopy after stained with 0.1％ red alizarin liquid.Results Little expression of fibronectin (brown granules under light microscope) could be seen in femur tissue of fluorosis rats of control group and lower calcium monophagia group; but abundantly expressed in fluoride group and lower calcium monophagia with fluoride group; the fibronectin was also expressed in osteoblasts,bone cells and bone marrow cells with less red particles in the control group and lower calcium monophagia group,but more in the fluoride group and lower calcium monophagia with fluoride group.The expression of fibronectin protein in supernatant of cultured osteoblasts was significantly increased in the group of 4 mg/L fluoride at 48 h(0.108 ± 0.042,t =0.764,P＜ 0.05) compared with control group(0.081 ± 0.010); the value was also significantly increased in 1,2,4 mg/L groups at 72 h(0.089 ± 0.010,0.087 ± 0.012,0.098 ± 0.023; t =0.765,0.704,0.996; all P ＜ 0.05) compared with control group (0.070 ± 0.014) ; the expression of fibronectin mRNA was much higher in 1,2,4 mg/L groups at 48 h (0.61 ±0.06,0.77 ± 0.07,0.77 ± 0.07) and 72 h(1.61 ± 0.14,2.54 ± 0.20,2.75 ± 0.22) compared with control group [0.48 ± 0.04(t =0.111,0.182,0.182,all P ＜ 0.05),0.97 ± 0.08(t =0.093,0.109,0.108,all P＜ 0.05) ].A lot of mineralized nodules could be seen under light microscope in 1.00 and 10.00 mg/L groups.Conclusions The expression of fibronectin in bone of fluorosis rats and in vitro cultured osteoblasts are increased,and fluoride also promotes the mineralization nodules formation of osteoblasts.These results suggest that fibronectin may regulate the process of bone mineralization,and possibly play a role in the development of skeletal fluorosis.

Objective　In view of the fact that asbestos is not only a key occupational hazard, but also an important environmental pollutant, it is necessary to develop a proper method to decrease the carcinogenecity of asbestos fibers. This study was designed to determine if the surface modification of chrysotile asbestos fiber (CAF) with rare earth compounds (REC) can ameliorate CAF-induced DNA damages in human embryo lung (HEL) cells. Methods　After incubation with REC solution at different concentrations at room temperature for 1 h, natural and REC-pretreated CAF was added to cell culture at various doses. At the selected time as the experiment designed, DNA damages of the HEL cells were detected by Unscheduled DNA Synthesis (UDS) and Single Cell Gel Electrophoresis (SCGE) assays. Results　The UDS induced by natural CAF was elevated with the increase of CAF doses. There was a good dose-response relationship between the UDS and the amount of CAF in the medium and the coefficient of correlation (R) was 0.958 at P<0.05. In REC-pretreated CAF groups, the UDS declined with the increase of REC doses. Both catalase (CAT) and dimethylsulfoxide (DMSO) also reduced the CAF-induced enhancement of UDS. In SCGE assay, CAF induced DNA chain breakage and the magnitude of DNA chain breakage increased in a dose-dependent manner and the coefficient of correlation (R) was 0.992 at p<0.01, while REC-pretreated CAF significantly decreased the induction of DNA chain breakage in a dose-dependent manner(r=0.989, p<0.05). Conclusion　It can be concluded that CAF-induced DNA damages in HEL cells may be partly mediated by oxygen derivatives, and the surface modification of CAF with REC might hide critical sites on the fiber surface, thereby reducing the fiber-mediated production of oxygen derivation and lowering the CAF-induced UDS and DNA chain breakage in HEL cells.

Syl948 is a synthesized selective S1P1 agonist with novel structure. HTRF-IP1 test indicated that Syl948-P, the active form of Syl948 in vitro, has strong activity against S1P1 (EC50: 83 +/- 16 nmol x L(-1)), but its effect on S1P3 was very weak (EC50: 1 026 +/- 90 nmol x L(-1)). In SD rats, oral administration of Syl948 10 mg x kg(-1) significantly decreased the peripheral blood lymphocytes (PBL), with the maximal PBL inhibition rate of 63%, which was as similar as equal dose of fingolimod (FTY720). Oral administration of Syl948 10 mg x kg(-1) had no effect on heart rate of SD rats, which was better than FTY720. Daily oral administration with Syl948 (2 or 4 mg x kg(-1)) significantly prolonged the survival time of the allografts of skin slice on mice. In summary, the above results demonstrated that Syl948 has great selectivity in vitro and good activity in vivo, which indicated its potential use as an anti-rejection drug in skin transplantation.
Animals ; Fingolimod Hydrochloride ; Graft Survival ; drug effects ; Immunosuppressive Agents ; pharmacology ; Lymphocytes ; drug effects ; Mice ; Propylene Glycols ; pharmacology ; Rats ; Receptors, Lysosphingolipid ; agonists ; Skin Transplantation ; Sphingosine ; analogs & derivatives ; pharmacology ; Transplantation, Homologous

OBJECTIVETo evaluate the influence of different tranexamic acid administration methods during and after cardiac surgery with cardiopulmonary bypass(CPB) on coagulation function and postoperative bleeding.

METHODSPatients undergoing elective cardiac surgery with use of CPB (n=60) were randomized in a double-blind fashion to one of two treatment groups:group A(n=30) , administered with tranexamic acid 10 mg/kg (intravenous injection slowly before skin incision) , followed by infusion of normal saline until postoperative 12 hours;and group B(n=30) , administered with tranexamic acid 10 mg/kg(intravenous injection slowly before skin incision) , followed by infusion of tranexamic acid 1 mg/(kg·h) until postoperative 12 hours. Hemoglobin, platelet count, and coagulation function were assessed before anesthesia induction, after surgery, 8am next day and 24 hours after surgery. Bleeding, allogeneic blood transfusion, and fluid infusion during the postoperative 24 hours were recorded.

RESULTNo differences were found between groups in terms of coagulant function, postoperative bleeding, allogeneic blood transfusion, and fluid infusion(P>0.05) .

CONCLUSIONCompared with intraoperative administration alone, prolonged treatment with tranexamic acid after cardiac surgery shows no advantage because it can not further improve coagulant function, reduce bleeding, or reduce allogeneic blood transfusion.

Adolescent ; Adult ; Aged ; Antifibrinolytic Agents ; administration & dosage ; therapeutic use ; Blood Coagulation ; drug effects ; Cardiac Surgical Procedures ; Cardiopulmonary Bypass ; Double-Blind Method ; Female ; Humans ; Male ; Middle Aged ; Perioperative Period ; Postoperative Hemorrhage ; prevention & control ; Postoperative Period ; Tranexamic Acid ; administration & dosage ; therapeutic use ; Young Adult