Objectives:To study the mechanical properties of human dentin obtained from vital and pulpless teeth. Methods:Dentin specimens were obtained from 20 freshly extracted normal vital human teeth and 9 endodontically treated human pulpless teeth. The dentin was grinded to be rectangular specimens along to the longitudinal axes of the teeth. All the specimens were immerged in 9 g/L sodium chloride solution, their compressive mechanical properties were measured with displacement measurement method. All data obtained were analyzed with t tests. Results:The elastic moduli,proportional limits and compressive strengths of the dentin samples from vital teeth were (15.77? 1.52 ) GPa, (157.07?13.79) MPa and (257.67?10.23) MPa respectively. Those from pulpless teeth were (12.08?1.71) GPa, (144.30?9.76) MPa and (235.26?9.12) MPa respectively(P

Expression and regulation of the P-glycoprotein (P-gp) is associated with the development of multidrug resistance in cancer.Cancer cells are exposed in endogenous damages from its own micro-environments and inflicted stimulated damages.These harmful micro-environments could trigger cellular stress response and regulated the expression of P-gp through various activated signal transduction pathways.Researches of the cellular endogenous micro-environments and exogenous stimulation damages on the expression and regulation of P-gp would have important significance for exploring the multidrug resistance of cancer cell.

Objective [WT5”BZ] To evaluate the role of duodenoendoscopy in the diagnosis and treatment of acute pancreatitis with gallstone (AP).[WT5”HZ] Methods [WT5”BZ] 45 AP cases were randomized into group of endoscopic retrograde cholangiopancreatography (ERCP) (n=20) and non ERCP group (n=25). All patients were further stratified into mild and severe subgroups according to APACHE Ⅱ scores. All cases were given supportive treatment combined with traditional Chinese medicine. The patients in ERCP group received ERCP within 24 hours of admission. If stones were found, endoscopic sphincterotomy (ES) was performed to extract the stones by basket. In cases with multiple stones or if no stone could be immediatly identifiable, endoscopic naso billiary drainage (ENBD) was applied.[WT5”HZ] Results [WT5”BZ]In patients with severe AP, the morbidity, length of hospital stay and cost were significantly lower in ERCP treatment subgroup than those without ERCP treatment (all P

Objective To explore clinical methods for preventing the recurrence of biliary pancreatitis.Methods Clinical data of 112 consecutive cases of acute biliary pancreatitis from January 1999 to July 2001 treated in this hospital were analyzed retrospectively.Before admission all the patients had no history of biliary pancreatitis or cholecystectomy.According to whether or not an endoscopic sphincterotomy(EST) or cholecystectomy was given,the patients were divided into 4 groups: Conservative Group(n=45),EST Group(n=22),Cholecystectomy Group(n=29),and Combination Group(n=16).The recurrence rates of pancreatitis of the 4 groups were compared each other.Results The 112 patients were followed for 16~30 months(mean,18.5 months).Recurrence of pancreatitis was found in 12 patients in the Conservative Group(26.7%,12/45) and in 2 patients in the Cholecystectomy Group(6.9%,2/29).No recurrence was seen in the EST Group and the Combination Group.As compared with the Conservative Group,both EST and cholecystectomy significantly decreased the recurrence rate of biliary pancreatitis.The 2 recurrent patients in the Cholecystectomy Group were given an endoscopic retrograde cholangiopancreatography(ERCP),by which small common bile duct calculi were found.Conclusions Common bile duct calculus is the major cause of recurrence of biliary pancreatitis.Both EST and cholecystectomy can decrease the recurrence rate of biliary pancreatitis.EST is suitable for elderly high-risk patients because of its minimal invasion.

BACKGROUND: Full-thickness skin graft was a base for bum and plastic surgery, while uniform pressure and regional brake were key factors to ensure skin graft survival and avoid from necrosis. Traditionally, package and pressurized fixation were performed after skin transplantation; however, it induced residual dead space and unclear skin graft fixation, as well as suturing scar.OBJECTIVE: To study the effect of vacuum sealing drainage applied to full-thickness skin graft.METHODS: A total of 8 New Zealand rabbits were used to establish full-thickness skin graft models in three regions of bilateral spine. Vacuum sealing drainage, traditional pressurized suture and common wrapping were performed in the three regions, respectively. The skin graft survival was observed, and survival rate was calculated at 14 and 21 days. On the 3rd, 7th, and 14th days, samples were selected from skin graft and stained. The morphology was observed under light microscope and transmission electron microscope. The time to remove the drain vessel was that when the fluid was not increased or the fluid was clear.RESULTS AND CONCLUSION: The survival rate of vacuum sealing drainage group was significantly higher than that in other two group (P < 0.05), while the survival rate of traditional pressurized suture group was significantly higher than that in the common wrapping group (P< 0.05). Morphology examination demonstrated that regional cuticular layer was necrotic in the vacuum sealing drainage group after early skin transplantation, while inflammatory cell infiltration, fibroblast degeneration, and mitochondrial swelling were also observed. At later skin transplantation, fibroblast and basal cell were proliferated, and function of mitochondria and plasmid was active. This suggested that vacuum sealing drainage promoted survival rate of skin graft.

BACKGROUND:Bone fragility and poor bone quality due to osteoporosis are a major and increasing concern. Bone microarchitecture and microdamage, the important factors of bone quality, their detection technology and instrument have experienced a long development process. OBJECTIVE:To give a brief introduction of the concept of the bone microarchitecture and microdamage, then to summarize the research progress of their detective methods. METHODS:PubMed and CNKI databases were retrieved for reviews and articles related to bone microarchitecture and microdamage published from January 1990 to June 2016 using the keywords of“bone microarchitecture, bone microdamage and detect/detective/detecting”in Chinese and English, respectively. Finaly a total of 65 articles were selected for overview. RESULTS AND CONCLUISON:(1) Bulk staining is a quick and useful way to confirm and assess linear microcracks and diffuse damage. Micro-CT and confocal microscopy al ow visualization at the micron scale, and are useful tools to understand the three-dimentional nature of bone microdamage. Scanning electron microscope lacks the ability to investigate large regions of microdamage, but al ows users to probe in extensive details at the nano scale. (2) Ultimately, we recommend the use of multiple imaging modalities according to the experimental needs to obtain useful information about bone quality and microdamage formation, across the scales of hierarchy in bone.

AIM:To explore whether cyclosporine A (CsA) can regulate the expression of nometastatic gene23 H1 type (nm23-H1) in human choriocarcinoma Bewo cells,in order to seek new proof of treating trophoblast diseases.METHODS:The Bewo cells were divided into two groups. The vehicle control group,and the CsA group with different concentrations from 10-2 ?mol/L to 10 ?mol/L. The effect of CsA on the transcription of nm23-H1 was determined by reverse transcription-polymerase chain reaction (RT-PCR) after cultured for 48 h and protein level of nm23-H1 was determined by In-cell Western after cultured for 72 h.RESULTS:Compared to the vehicle group,CsA significantly downregulated the transcription and translation of nm23-H1 in a dose-dependent manner from 10-2 ?mol/L to 10 ?mol/L,and the inhibition reached its top when concentration of CsA was 1.0 ?mol/L (P

Objective To explore the effect of the unilateral lumbar anesthesia by hypobaric bupivacaine and general anesthe‐sia in elderly hip replacement and their influence on the stress response .Methods Forty elderly patients undergoing hip replace‐ment in our hospital from December 2013 to November 2014 were selected and randomly divided into the unilateral lumbar anesthe‐sia group and general anesthesia group according to the random number table ,20 cases in each group .Venous blood was collected to determine the levels of blood sugar ,serum catecholamine(CA) and cortisol(CORT ) at 10 min before anesthesia(T0 ) ,end of surgery (T1 ) and at postoperative 24 h(T2 ) .MAP ,HR ,SpO2 ,intraoperative adverse reactions and postoperative related complications were recorded at each time point ,and the comparative analysis was performed .Results All patients successfully completed surgery and the anesthetic effect was satisfied .The occurrence rates of intraoperative hypotension ,hypertension and bradycardia in the unilateral lumbar anesthesia group were lower than those in the general anesthesia group ,the differences had statistical significances (P>0 .05) .HR and MAP at T1 in the two groups were reduced ,but the differences between the two groups were no statistical signifi‐cance(P>0 .05);the levels of GLU ,CORT and CA were increased ,moreover the differences between the two groups were statisti‐cally significant(P<0 .05) .SpO2 at T2 in the general anesthesia group was obviously lower than that in the unilateral lumbar anes‐thesia group ,while CORT was higher than that in the unilateral lumbar anesthesia group ,the differences were statistically signifi‐cant(P<0 .05) .The occurrence rates of postoperative nausea and vomiting ,sore throat ,dizziness ,drowsiness and pulmonary infec‐tion in the unilateral lumbar anesthesia group were lower than those in the general anesthesia group ,the differences were statistical‐ly significant(P<0 .05) .Conclusion The unilateral lumbar anesthesia by using hypobaric bupivacaine and general anesthesia all could offer better anesthetic effect .The unilateral lumbar anesthesia by using hypobaric bupivacaine can effectively regulate the stress response in elderly patients with hip replacement .

Objective To evaluate the effects of dexmedetomidine on the cerebral oxygen metabolism in elderly patients undergoing general anesthesia.Methods Sixty ASA physical status Ⅰ or Ⅱ patients,aged 60-87 yr,scheduled for elective abdominal surgery under general anesthesia,were randomly divided into 2 groups (n =25 each) using a random number table:control group (group C) and dexmedetomidine group (group D).Anesthesia was induced with iv injection of midazolam,fentanyl,atracurium and propofol.The patients were tracheally intubated and mechanically ventilated.In group D,dexmedetomidine 1.0μg/kg was infused intravenously over 20 min before induction of anesthesia,while the equal volume of normal saline was given in group C.Before induction of anesthesia,at 0 and 10 min after tracheal intubation and at the end of operation (T0-3),blood samples were taken from the radial artery and jugular bulb for blood gas analysis.Arteriovenous blood O2 content difference (DajvO2) and cerebral O2 extraction rate (CERO2) were calculated at the same time.The development of emergence agitation and postoperative delirium within 48 h after surgery were recorded.Resets Compared with the baseline values at T0,the Da-jvO2 and CERO2 were significantly decreased at T1-3 in the two groups (P ＜ 0.05).Compared with group C,the Da-jvO2 and CERO2 were significandy decreased at T2-3,and the incidence of emergence agitation and postoperative delirium within 48 h after surgery was decreased in group D (P ＜ 0.05).Conclusion Dexmedetomidine can improve the cerebral oxygen metabolism and reduce the development of postoperative delirium in elderly patients undergoing general anesthesia.

BACKGROUND:Methylprednisolone has been used for the treatment of acute spinal cord injury but there is a dispute about the efficacy and safety of methylprednisolon. OBJECTIVE:To evaluate the efficacy and safety of methylprednisolon based on system review. METHODS:PubMed database, EMBASE database, Cochrane Library, ISI Web of knowledge, CBM database, VIP database, CNKI database and Wanfang database were searched from their start year up to December 2014 for relevant randomized clinical trials on the treatment of acute spinal cord injury with methylprednisolon. RESULTS AND CONCLUSION:Twelve randomized clinical trials with 642 acute spinal cord injury patients were included. The results of the Meta analysis showed: methylprednisolone+conventional therapy was better to improve American Spinal Injury Association (ASIA) motor function score, ASIA touch sensation score, ASIA pinprick sensation score and the overal Frankel score than the conventional therapy alone (control group) with statistical significance (P < 0.05). In the aspect of safety, the methylprednisolone group had higher death ratio, digestive tract reaction ratio and urinary infection ratio than the control group but with no statistical significance. The gastrointestinal bleeding ratio and lung infection ratio was significantly higher in the methylprednisolone group than the control group (P < 0.05). We conclude that methylprednisolone has protective effect on acute spinal cord injury, but the main side effects are gastrointestinal bleeding and lung infection. There is a need for high-quality randomized controled trials to prove the efficiency and safety of methylprednisolone.