BACKGROUND:A number of in vitro experiments have confirmed that the tricalcium silicate not only can be closely integrated with the dentin through self-curing process, but also can induce dentin remineralization in the physiological environment, thereby effectively blocking the dentinal tubules.
OBJECTIVE:To further verify the effects of tricalcium silicate solution on the occlusion of dentinal tubules.
METHODS:Thirty-six dentinal discs were made of free first premolars from orthodontic patients, and divided into three pretreatment groups randomly. The teeth were soaked in pretreatment solution for 2 minutes, namely 0.29 mol/L ethylene diamine tetraacetie acid, 6%citric acid, and rinsed ultrasonical y with deionized water 20 minutes, respectively. Every above-mentioned group was randomly assigned into experimental group (tricalcium silicate), control group (sodium fluoride) and blank group, and corresponding materials in each group were used to coat the outer dentinal tubules (2 minutes/time). Then, the dentinal discs were saved in artificial saliva in a 37 observed using scanning electron microscope. Diameter and area of open dentinal tubules were calculated.
RESULTS AND CONCLUSION:After pretreatment, the dentinal tubules were at open state;except for the blank control group to maintain the original state, acid etching and ethylene diamine tetraacetie acid pretreatment solutions had a stronger capacity of demineralization, which led to the dentinal tubules open. After the dentinal tubules were treated with sodium fluoride and tricalcium silicate, there were varying degrees of sediments, and open dentinal tubule area and average diameter in the sodium fluoride and tricalcium silicate groups were lower than those in the control group (P<0.05). The dentinal tubule treated with tricalcium silicate was almost entirely closed homogeneously, and occasional y, a single open dentinal tubule was seen. Open dentinal tubule area and average diameter in the tricalcium silicate group were significantly lower than those in the sodium fluoride group (P<0.05). The findings verify that dentin occlusion using tricalcium silicate is superior to that using sodium fluoride;and dentin tubule pretreatment with acid etching or ethylene diamine tetraacetie acid is beneficial to desensitization effects.

Objective To survey the biliary flora in patients with obstructive jaundice due to pancreatic head cancer,also the multiple factors which affect the positive findings of bile culture in these patients.Methods The information of 65 patients with obstruetive jaundice due to pancreatic head eancer,who admitted to surgery in Huashan Hospital from Oetober 2007 to October 2008 were reviewed retrospectively.The factors which may potentially affect the detection of bile pathogen in patients with malignant obstructive jaundice were studied with univarite analysis and muhivariate analysis,including age,history of biliary surgery,yellow stained time,serum alanihe aminotransferase level,serum bilirubin level,CA19-9 level,tumor size,site of obstruction,with or without clinical manifestations of biliary infection,and APACHE Ⅱ score.Results Twenty-five positive cultures happened in 65 bile samples (38.5％),including 21 strains of Gram-negative baeilli (72.4％),6 strains of Gram-positive bacteria (20.7％),and 2 strains of fungi (6.9％).Univariate analysis showed that the relevant factors which may affect the rate of positive bile culture in patients with malignant obstructive jaundice were age,history of biliary surgery,biliary obstruction site,biliary tract infection symptoms and APACHE Ⅱ score.Multivariate analysis showed that age,history of biliary surgery,biliary obstruction site and APACHE Ⅱ seore were independent risk factors.Conctusion Age,history of biliary surgery,biliary obstruction site and APACHE Ⅱ score were independent risk factors which led to positive findings of bile cultures in patients with obstructive jaundice due to pancreatic head cancer.

BACKGROUND: Ischemic postconditioning protects the myocardium from ischemia/recursion injury via maintaining 3-minute acidosis initially. But its effect on the skeletal muscle remains unclear. OBJECTIVE: To dynamically measure the pH values in rat skeletal muscle after ischemia, and then to simulate acidic perfusate infusion to investigate the effect of ischemic postconditioning on ischemia/reperfusion injury. METHODS: Based on the ischemia/reperfusion injury model and ischemic postconditioning protocol in previous study, dynamic measurement of pH values in rat skeletal muscle was conducted using pH instrument at the global ischemia, ischemic postconditioning (30/30 seconds) and reperfusion period, and then the acidic perfusate equivalent to pH in ischemic postconditioning period was prepared with lactic acid and normal saline. Twenty-five healthy adult male Sprague-Dawley rats were randomly divided into sham, ischemia/reperfusion, ischemic postconditioning, lactic acid, and normal saline groups (n=5 per group). Blood samples were collected to detect lactate dehydrogenase level. The samples from gastrocnemius were harvested to calculate the wet/dry ratio, level of myeloperoxidase, and infarct size through triphenyltetrazolium chloride staining. The samples from the right tibialis anterior muscle were taken to detect the expression level of Erk1/2 in the MAPK signaling pathway by western blot assay. RESULTS AND CONCLUSION: A prolonged acidic platform was detected in the early reperfusion during ischemic postconditioning, on which the pH value was 6.81±0.133, and the duration was 2 minutes and 40 seconds. The levels of lactate dehydrogenase and myeloperoxidase as well as the wet/dry ratio in the ischemic postconditioning and lactic acid groups were significantly lower than those in the ischemia/reperfusion group (P < 0.05). Western blot assay results showed that the expression level of p-Erk in the ischemic postconditioning, lactic acid and normal saline groups was significantly higher than that in the ischemia/reperfusion group (P < 0.05). Triphenyltetrazolium chloride staining results showed that compared with the ischemia/reperfusion group, the infarct area was significantly reduced in the postconditioning and lactic acid groups (P < 0.05). These findings suggest the existence of a short acidosis during ischemic postconditioning in the early reperfusion, and acidic perfusate can simulate the ischemic postconditioning and effectively attenuate ischemia/reperfusion injury in the rat skeletal muscle via activating Erk1/2 in RISK signaling pathway.

ObjectiveTo investigate the accuracy of three laparoscopic liver resection (LLR) difficulty score systems (DSSs) in evaluating surgical difficulty and predicting short-term postoperative outcome. MethodsThe retrospective cohort study was conducted for 142 patients who underwent LLR in The First Hospital of Lanzhou University from June 2015 to May 2020, and their preoperative, intraoperative, and postoperative clinical data were collected. According to preoperative clinical data, DSS-B score, Hasegawa score, and Halls score were used to determine the difficulty score of surgery for each patient, and then the patients were divided into low, medium, and high difficulty groups. Intraoperative data were compared between the three groups to verify the accuracy of the three DSSs, and postoperative clinical data were used to evaluate the ability of DSSs to predict short-term postoperative outcome. An analysis of variance was used for comparison of normally distributed continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups; the Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between multiple or two groups. The chi-square test or the Fisher’s exact test was used for comparison of categorical data between groups, and the Bonferroni method was used for correction of P values between two groups. The receiver operating characteristic (ROC) curve was plotted and the area under the ROC curve (AUC) was calculated to evaluate the efficiency of each DSS in predicting postoperative complications. ResultsAmong the 142 patients, there were 37 patients in the low difficulty group, 56 in the medium difficulty group, and 49 in the high difficulty group based on DSS-B score; there were 70 patients in the low difficulty group, 47 in the medium difficulty group, and 25 in the high difficulty group based on Hasegawa score; there were 46 patients in the low difficulty group, 62 in the medium difficulty group, and 34 in the high difficulty group based on Halls score. For the low, medium, and high difficulty groups based on DSS-B score, Hasegawa score, or Halls score, time of operation, intraoperative blood loss, and rate of hepatic portal occlusion increased with the increase in difficulty score (all P＜0.001); there was a significant difference in intraoperative blood transfusion rate between the medium and high difficulty groups based on DSS-B score (P＜0.017), between the low and high difficulty groups based on Halls score (P＜0.017), and between the low, medium, and high difficulty groups based on Hasegawa score (P＜0.017). There was a significant difference in the rate of conversion to laparotomy between the medium and high difficulty groups based on DSS-B score (P＜0.017), and Hasegawa score and Halls score identified the difference between the low and high difficulty groups (P＜0.017). For the length of postoperative hospital stay, DSS-B score and Halls score only identified the difference between the low and high difficulty groups (P＜0.05), while Hasegawa score identified the difference between the low difficulty group and the medium/high difficulty groups (P＜0.05); for the incidence rate of postoperative complications, only Hasegawa score effectively identified the difference between the high difficulty group and the low/medium difficulty groups (P＜0.017). DSS-B score, Halls score, and Hasegawa score had an AUC of 0.636 (95% confidence interval ［CI］: 0.515-0.758), 0.557 (95% CI: 0.442-0.673), and 0.760 (95% CI: 0.654-0.866), respectively, in predicting postoperative complications, among which Hasegawa score had the highest predictive efficiency. ConclusionDSS-B score and Hasegawa score can better assess the difficulty of LLR, and Hasegawa score has an advantage in predicting short-term postoperative outcome.

ObjectiveTo study the characteristics and the impact of lymph node metastasis on radical resection for pancreatic head cancer to provide a theoretical basis for lymphadenectomy in radical resection.To study the reliability of using a surgical microscope to detect lymph nodes in radically resected specimens of pancreatic head cancer.MethodsLymph nodes in the specimens after radical pancreaticoduodeneetomy (pancreaticoduodenectomy + D2 regional lymphadenectomy) were identified using a surgical microscope and they were grouped using the JPS standard.The position and the frequency of the lymph nodes retrieved,and their association with other clinicopathologic factors were analysed.The results were compared with the data published in 2004 on 46 patients to evaluate the reliability of using a surgical microscope.ResultsLymph node metastasis was detected histopathologically in 101 patients (67.3％).The median number of lymph nodes retrieved in the specimens as detected using the surgical microscope was 38.2.The most commonly involved lymph node groups were No.13 (64.5％),No.14 (51.7％),No.17 (38.6％),No.12 (25.8％),No.16 (20.8％).Lymph node metastasis was significantly associated with tumour T stage,tumour invasion and differentiation,preoperative serum level of CA19-9 and CA72-4,but not with patient age,sex,or tumour location.There were no significant differences between the results and the data of the previous study in 2004.ConclusionsExtended lymphadenectomy is necessary because extensive lymph node metastasis was common.Surgical microscopy is an effective and reliable method to detect lymph nodes in resected specimens of pancreatic head cancer for accurate pathologic staging.

The application of artificial retina was introduced. The principal characteristics of artificial retina material were reviewed in particular. Moreover, the recent research development and application prospect were discussed.
Animals ; Bioartificial Organs ; trends ; Humans ; Prosthesis Design ; Retina ; Tissue Engineering ; methods

Subretinal prosthesis is one kind of retinal prosthesis, which means that a microimplant based on MEMS technology is inserted in the subretinal space to stimulate the optic nerve and elicit an electrical-evoked response on the cortical region. The subretinal implant is made up of extraocular part and intraocular part. As an important part, the latter consists of accessorial setting and stimulation chip that contains microphotodiode array (MPDA) and microelectrodes. The paper main body is made up of four parts. Firstly significance of the retinal prosthesis is given out; secondly fundamentals on both in retina physiology and retinal prosthesis theory are introduced simply. Then the key segment about the subretinal microimplant is presented in detail. In the third segment, first of all is its design concept, the second is fabrication of MPDA which consists of several parts. First is microscopic configuration, electric prototype schematic and chip image CMOS. The second is detailed fabrication flow with several special materials. Then is situation of its dimension. The fourth segment presents challenge and outlook.
Artificial Organs ; Electric Stimulation Therapy ; instrumentation ; Electrodes, Implanted ; Evoked Potentials, Visual ; physiology ; Humans ; Microelectrodes ; Prosthesis Implantation ; methods ; Retina ; physiology ; surgery ; Visual Perception ; physiology

Objective:The purpose of this study was to investigate the clinical value of CT-guided localization of pulmonary nodules with soft wire hook-wire by trailing technique.Methods:The clinical data of 211 pulmonary nodules of 185 patients from November 2020 to March 2022 in Beijing Aerospace General Hospital were retrospectively analyzed. The pulmonary nodules were localized with soft wire hook-wire by trailing technique before video-assisted thoracic surgery (VATS). The success rate, complications, pathological results and localization operations related data were statistically analyzed.Results:The success rate of localization was 97.63% (206/211), and the success rate of VATS removal was 99.53% (210/211). The average operation time was (7.19 ± 2.62) min, and the average time required for resection of lesions was 27 min (10 to 126 min). During the surgery, the soft wire hook-wire of two patient was found to be dislocated and retracted into the chest wall. The pulmonary nodules were successfully located and removed according traces left by puncture points on the lung surface. It was found that the hook-wire was located in the interlobar fissure in 3 patients. The pulmonary nodules were successfully removed by the hook-wire position and appropriately expanding the resection range. A minor pneumothorax occurred in 49 patients, but no closed drainage was needed; 12 patients developed intrapulmonary hematoma; 15 patients with chest pain were treated with analgesia.Conclusions:For small pulmonary nodules requiring thoracoscopic surgery, the computed tomography-guided pulmonary nodule localization with soft wire hook-wire by trailing technique is more convenient, safe and effective, and is worthy of promotion to use.

Hepatolithiasis is a common and persistent disease in hepatobiliary surgery, which is one of the most important leading causes of death in patients with benign biliary tract diseases. Traditional of diagnosis and treatment options of hepatolithiasis have limitations, recently the rising of three-dimensional visualization technology provides doctors with fresh thinking and approaches. Three-dimensional visualization technology can accurately evaluate the anatomical structure and pathological condition of the liver, at the same time it plays an important role in guiding hepatectomy, choledochoscopic lithotripsy and biliary drainage. Three-dimensional printing and intraoperative navigation, which based on three-dimensional visualization technology, also has good application prospects. This paper summarized the application of three-dimensional visualization technology for the diagnosis and treatment of hepatolithiasis in order to help the future research.

Objective:To measure the anatomical parameters of the simulated low tibial tunnel of posterior cruciate ligament (PCL) based on knee CT images so as to provide clinical reference for accurate location of the tunnel.Methods:The CT images of 201 healthy knee joints collected at Department of Orthopedics, The Second Hospital of Lanzhou University from June 2016 to September 2021 were used for simulation of the PCL low tibial tunnel. The anatomical parameters of the tibial tunnel were measured using the RadiAnt DICOM Viewer. The primary measures included the angle between tibial plateau and tibial tunnel (ATPT) and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau (L1 and L2). The secondary measures included the angle between tibial plateau and posterior slope (PSA), the angle between tibial anatomical axis and central line of tibial tunnel (ATAA), the angle between posterior tibial slope line and the central line of tibial tunnel (APST), the anterior and posterior diameter of tibial plateau (APD), the length of posterior tibial slope (LPTS), and the length of tibial tunnel (LTT). The measurement results were analyzed according to the body height (divided into 3 groups: a 1.00 to 1.60 m group, a 1.61 to 1.70 m group, and a ≥1.71 m group) and gender using the software IBM SPSS 26.Results:The primary measures: ATPT was 37.0°±4.5°, and L1 and L2 were respectively (57.8±7.4) mm and (34.5±3.3) mm. The secondary measures: PSA 128.1°±5.4°, ATAA 52.7°±4.1°, APST 89.1°±5.9°, APD was (32.9±2.6) mm, LPTS (20.5±2.4) mm, and LTT (40.9±5.7) mm. After grouping by gender, there was no significant difference in PSA between men and women ( P>0.05) while there were significant differences in the other indexes between men and women ( P<0.05). After grouping by body height, there was no significant difference in ATPT, PSA, APST or ATAA between the 3 groups (1.00 to 1.60 m group, 1.61 to 1.70 m group and ≥1.71 m group) ( P>0.05) while there were significant differences in L1, L2, APD, LPTS and LTT between the 3 groups ( P<0.05). Conclusions:Based on the knee CT images, the primary measures of PCL low tibial tunnel are as follows: the angle between tibial plateau and tibial tunnel is 37.0°±4.5°, and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau are (57.8±7.4) mm and (34.5±3.3) mm, respectively. Gender and body height are the important factors influencing the above measurement outcomes.