more coincidence with ultrasound than SPECT. ConclusionsUltrasonography is a noninvasive method for assessing the effect of multiple burr-hole operation in patients with moyamoya disease.

Objective To study the effect of nicorandil on the function of coronary artery endothelium during hypoxiareoxygenation.Methods Forty-five fresh porcine left anterior descending coronary artery rings in 2mm long were randomly divided into five groups.Control group ( n =9):incubation in Krebs-Henseleit (KH) at 37℃ for 90 minutes with a constant supply of oxygen ; Group A ( n =9):30-minute hypoxia ( PO2 ＜ 15 mm Hg) followed by 30 minutes reoxygenation in KH at 37℃ ; Group B ( n =9):60-minute hypoxia followed by 30 minutes reoxygenation in KH at 37 ℃ ; Group C ( n =9):60-minute hypoxia followed by 30 minutes reoxygenation in KH added nicorandil ( 0.2 μmol/L) at 37 ℃ ; Group D ( n =9 ):60-minute hypoxia followed by 30 minutes reoxygenation in KH added nicorandil (0.2 μmol/L) and 5-hydroxydecanoate ( 10μmol/L) at 37 ℃.The endothelium-derived hyperpolarizing factor (EDHF) -mediated relaxation ( U46619 precontraction) induced by bradykinin in the present of indomethacin (7 μmol/L),LNNA (300 μmol/L) and oxyhemoglobin (20 μmol/L)were measured in the organ chambers.Results Compared with control group,the relaxation was significantly decreased in group A,B and D ( P ＜ 0.001 ),while there is no significant difference in group C ( P ＞ 0.05 ).Compared with group A,the relaxation was significantly reduced in group B and D (P ＜0.001 ).Conclusion Hypoxia-reoxygenation impairs EDHF mediated relaxation in coronary artery with more injury during prolonged hypoxia.This function can be restored by preconditioning with nicorandil The mechanism is mainly related to the mitochondrial ATP-sensitive K + channels.

Objective To evaluate the value of ultrasound in assessing superficial temporal arterymiddle cerebral artery(STA-MCA)anastomosis in patients with moyamoya disease.Methods Ultrasonic Doppler studies were made pre-and postoperatively in 25 patients with moyamoya disease undergoing STAMCA anastomosis.The peak systolic velocity(PSV),end diastolic velocity(EDV),pulsatility index(PI)and resistance index(RI)were measured in external carotidartery(ECA) and superficial temporal artery (STA)pre-and postoperatively.The pattern of the collateral circulation through the bypass was categorized based on postoperative external carotid angiograms.Thus three categories were determined as extensive,moderate and poor.The patients were divided into three groups based on the pattern of the collateral circulation through the bypass,which was determined based on the angiographic findings.PSV,EDV,PI,RI of STA was compared between groups.Results ①The values of the PSV,EDV of anastomosed STA were significantly higher and the values of PI,RI were significantly lower after operation.②The values of the PSV,EDV of the anastomosed ECA tended to be higher and the values of PI,RI tended to be lower in postoperation patients,but the differences were not significant within preoperation and postoperation group.③The Values of the PSV,EDV of the anastomosed STA were significantly different among the groups.The PSV.EDV tended to be higher and the PI,RI tended to be lower in patients with more extensive bypass flow.④The blood flow direction of STA was from extracranial to intracranial.Conclusions The PSV,EDV,PI,RI of STA can predicting the extent of collateral flow through an STA-MCA bypass.Color Doppler ultrasonography is a noninvasive method of assessing the function of STA-MCA bypass in patients with moyamoya disease.

OBJECTIVETo investigate the effect of hypoxia on the expression of matrix metalloproteinase (MMP) and tissue inhibitors of matrix metalloproteinase (TIMP) in human periodontal ligament fibroblasts (HPDLF).

METHODSHPDLF were cultured in α-minima essential medium (α-MEM) and subcultured at confluence. In the hypoxic groups, cells were incubated in a humidified atmosphere of 1%O(2), 5%CO(2), 94%N(2) at 37°C for 12, 24 and 48 h, respectively. In the normoxic control group, cells were incubated under normoxic conditions of 20%O(2), 5%CO(2), 75%N(2). The mRNA expression of MMP and TIMP was measured using reverse transcription-polymerase chain reaction (RT-PCR). The data was analyzed by Student's t test, one-way ANOVA and LSD test with SPSS 13.0 software package.

RESULTSThe expression of MMP-2, TIMP-1 and TIMP-2 mRNA in the hypoxia groups was higher than that in control. The expression of MMP-2 mRNA in hypoxic groups showed a significantly increasing trend. There was significant difference between the hypoxic group and the normoxic control group in the expression of MMP-2 mRNA in HPDLF (P < 0.01). The expression of TIMP-1, TIMP-2 mRNA in hypoxic groups of 12 h was momentarily increased. There was significant difference between the hypoxic 12 h group and the normoxic control group in the expression of TIMP-1, TIMP-2 mRNA in HPDLF (P < 0.05). However, with prolonged hypoxia time, the expression of TIMP-1, TIMP-2 mRNA in hypoxic groups showed a significantly declining trend, there were significant differences between the hypoxic 12, 24 and 48 h group and the normoxic control group in the expression of TIMP-2 mRNA in HPDLF (P < 0.05). The expression of MMP-1 mRNA in hypoxic groups of 12 h was momentarily decreased and then increased after 24 h of hypoxia. There were significant differences between the hypoxic 48 h group and the normoxic control group in the expression of MMP-1 mRNA in HPDLF (P < 0.05). There were significant differences between the hypoxic 12 h group and the normoxic control group in the ratio of MMP-1/TIMP-1 mRNA (P < 0.05). The ratio of MMP-2/TIMP-2 mRNA in the hypoxia group significantly increased compared with normoxic group. There were significant differences between the hypoxic group and the normoxic control group in the ratio of MMP-2/TIMP-2 mRNA (P < 0.05).

CONCLUSIONSHypoxia could change the expression of MMP and TIMP mRNA and other relevant growth factors and also lead to the imbalance of MMP-2/TIMP-2 mRNA expression. It is suggested that the imbalance of MMP-2/TIMP-2 expression may be closely correlated with the occurrence and development of periodontal disease and play an important role in the process of periodontal tissue destruction in periodontitis.

Adolescent ; Cell Hypoxia ; Cells, Cultured ; Fibroblasts ; cytology ; metabolism ; Humans ; Matrix Metalloproteinase 1 ; genetics ; metabolism ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Periodontal Ligament ; cytology ; RNA, Messenger ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Tissue Inhibitor of Metalloproteinase-1 ; genetics ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; genetics ; metabolism

Objective To explore the clinical application value of combined detection of apolipoprotein A1(ApoA1)and alpha-fetoprotein(AFP)in young and middle-aged patients with pulmonary tuberculosis.Meth-ods A total of 82 young and middle-aged patients with pulmonary tuberculosis admitted to the hospital from December 2020 to December 2021 were selected as the observation group,and 85 healthy people who under-went physical examination in the hospital during the same period were selected as the control group.The clini-cal,lipid,inflammation and iron metabolism related indexes were compared between the two groups.Multiva-riate Logistic regression was used to analyze the influencing factors of pulmonary tuberculosis in young and middle-aged patients.The area under the receiver operating characteristic(ROC)curve(AUC)was used to e-valuate the application value of ApoA1,AFP and their combination in the diagnosis of pulmonary tuberculosis in young and middle-aged patients.Results Compared with the control group,the observation group had sig-nificantly higher levels of direct bilirubin,creatinine,AFP and high-sensitivity C-reactive protein(P<0.05),and significantly lower levels of triglyceride,total cholesterol,high-density lipoprotein cholesterol and ApoA1(P<0.05).Multivariate Logistic regression analysis showed that ApoA1 was an independent protective factor(OR=0.119,95%CI 0.019-0.754,P=0.024)and AFP was an independent risk factor(OR=1.554,95%CI 1.138-2.122,P=0.006)for pulmonary tuberculosis in young and middle-aged patients.ApoA1,AFP and the combined prediction of young and middle-aged tuberculosis AUC were 0.644(P=0.006),0.262(P<0.001),0.678(P=0.001),respectively.Conclusion The low level of ApoA1 is an independent protec-tive factor for pulmonary tuberculosis in young and middle-aged patients,and the high level of AFP is an inde-pendent risk factor for pulmonary tuberculosis in young and middle-aged patients.The combined detection of ApoA1 and AFP has good value in predicting pulmonary tuberculosis in young and middle-aged patients.

The standardized workflow of computer-aided static guided implant surgery includes preoperative examination, data acquisition, guide design, guide fabrication and surgery. Errors may occur at each step, leading to irreversible cumulative effects and thus impacting the accuracy of implant placement. However, clinicians tend to focus on factors causing errors in surgical operations, ignoring the possibility of irreversible errors in nonstandard guided surgery. Based on the clinical practice of domestic experts and research progress at home and abroad, this paper summarizes the sources of errors in guided implant surgery from the perspectives of preoperative inspection, data collection, guide designing and manufacturing and describes strategies to resolve errors so as to gain expert consensus. Consensus recommendation: 1. Preoperative considerations: the appropriate implant guide type should be selected according to the patient's oral condition before surgery, and a retaining screw-assisted support guide should be selected if necessary. 2. Data acquisition should be standardized as much as possible, including beam CT and extraoral scanning. CBCT performed with the patient’s head fixed and with a small field of view is recommended. For patients with metal prostheses inside the mouth, a registration marker guide should be used, and the ambient temperature and light of the external oral scanner should be reasonably controlled. 3. Optimization of computer-aided design: it is recommended to select a handle-guided planting system and a closed metal sleeve and to register images by overlapping markers. Properly designing the retaining screws, extending the support structure of the guide plate and increasing the length of the guide section are methods to feasibly reduce the incidence of surgical errors. 4. Improving computer-aided production: it is also crucial to set the best printing parameters according to different printing technologies and to choose the most appropriate postprocessing procedures.