Root canal therapy is the most efficient way to treat pulptitis and periapical inflammation, which can clear infections of root canal systems, fill the root canal firmly, and avoid reinfection. However, the variations in root canal morphology and complexity of infection confer difficulty in thoroughly eliminating microorganisms and their by-products in the root canal system, especially in the root apex area (including the top one-third of the root canal and periapical tissue), which is described as the hardest area to clean during endodontic treatment. Infection is difficult to remove entirely because the apex area is hard to approach using dental instruments and because of the existence of special morphological structures, such as apical ramification, intercanal anastomoses, and lateral branch of root canal. This review gives a brief introduction of the characteristics and difficulties of apical infection and knowledge on how to control such infections, including root apex preparation, irrigation and disinfection, and root canal filling.
Dental Pulp Cavity ; Humans ; Infection Control ; Periapical Periodontitis ; Root Canal Filling Materials ; Root Canal Irrigants ; Root Canal Obturation ; Root Canal Preparation ; Root Canal Therapy

Objective To investigate the impact of alterations within the space of Disse micro- environment on the migration of hepatic stellate cells(HSC) during the process of liver fibrosis,and to ex plore the novel mechanism of liver fibrosis from the view of cell migration.Methods A modified in vitro Boyden chamber system to partially mimic in vivo microenvironment of Disse space of normal and liver fibrosis was employed.The effects of fibrogenetic growth factors on the migration of HSC in liver fibrosis were observed via cell migration and cell proliferation experiments.Results Enhanced platelet-derived growth factor(PDGF)-BB,transforming growth factor(TGF)-?1 and/or epithelial growth factor(EGF) in liver fibrosis resulted in an increase in migratory capacity of activated HSC.The enhanced migration of HSCs induced by PDGF-BB was partially associated with their increased proliferation,while,TGF-?1 or EGF-induced migration was proliferation independent.The elevation of basic fibroblast growth factor (bFGF) or vascular endothelial growth factor(VEGF)during liver fibrosis had no effect on the migration of HSCs.Conclusions The study provides valuable insights into the role of space of Disse microenvironment in regulating HSC migratory behavior.TGF-?1,PDGF-BB and EGF,which increased in liver fibrosis, could induce the migration of activated HSC.However,bFGF or VEGF has no such kind of effect,al- though they also increased during liver fibrosis.

The microstructure of cationic cyclopeptide (TD-34) treated Caco-2 cell membrane was observed, and we discussed the relationship between membrane structure and insulin transmembrane permeability. Atomic force microscope (AFM) was used to observe living cell membrane in air condition and tapping mode. Results showed that the surface of Caco-2 cell membrane treated with TD-34 lost its smoothness and nearly doubled its roughness. Apparent permeability coefficients (P(app)) of insulin in Caco-2 cell monolayers increased 2.5 times. In conclusion, AFM can be used to observe microstructure of cationic cyclopeptide treated cell membrane and cationic cyclopeptide enhanced insulin delivery across Caco-2 cell membrane by increasing membrane fluidity.

Objective: To analyze the prescription dosage for discharged patients in our hospital and investigate the potential risks.Methods: A retrospective research method was adopted to statistically analyze 55 872 discharge instructions from July to September in 2015,and more attention was paid to the prescriptions with dosage over 4 weeks,expecially the ones with 26-week dosage, and the related influencing factors were studied as well.

Objective To investigate the clinical features ,diagnosis and treatment of cesarean scar pregnancy (CSP) .Methods We retrospectively analyzed the medical history ,clinical manifestation ,diagnoses ,treatments and outcomes of 42 patients with ec‐topic pregnancy in the cesarean scar .Results All cases got diagnosed by transvaginal ultrasound .The error rate of first diagnosis was 40 .4% (17/42) .There were 25 cases of conservative therapy ,in which 12 cases were resolved with laparoscopic surgery and 1 case resolved with open surgery ;in the first process 15 cases were carried out laparoscopic surger in which 1 case were converted to laparotomy ;abdominal surgery were underwented in 1 case and were cured .Only one case underwent abdominal total hysterectomy as of failure after uterine artery embolization .After initial conservative treatment 3 cases were hospitalized again and 2 cases under‐went reoperation .41 patients were successfully retained the uterus and normal menstrual cycle returned at two months after opera‐tion .Conclusion The early diagnosis for CSP mainly depended on ultrasound and the thickness of incision muscle layer is an impor‐tant basis for choice of treatment .Checking the thickness of incision muscle layer for CSP mainly depended on ultrasound ,and lapa‐roscopic surgery is an ideal method for diagnosis and treatment of CSP .

This paper presents a new medical data visualiz ation method called multi-resolution blending rendering which has been deve lope d for visualizing the large medical volume data sets. Different from those multi -resolution rendering methods which simplify the structures by polygon mesh opt imization technique, the new method uses different resolution levels to represen t different parts of a structure at the same time. So, it can preserve the integ rality of the structure and emphasize the important part of the structure when simplifying the structure. The new method also takes advantage of the good qualit ies of the wavelet transform and constructs the multi-resolution blending model of the structureby orthogonal wavelet transform and transition operator. The experiment proves that our method can effectively simplify the model of the structure, enormously reduce the number of the triangle of the structure and speedup the structure rendering. It is especially suitable for interactive observations on a complex medical structure.

Objective:To investigate the expression of HIF-1?and its relationship with angiogenesis in osteosarcoma.Methods: Osteosarcoma MG-63 cells were cultured in vitro under hypoxia and mimic hypoxia conditions.Thirty paraffin-embedded osteosarcoma tissues and 20 fresh frozen osteosarcoma specimens were collected.The mRNA and protein expression of HIF-1?and VEGF were detected by RT-PCR,Western blotting,ELISA,and immunohistochemistry methods.The mean vessel density(MVD)were also calculated.Results:The mRNA level of HIF-1?had no change under hypoxia and minic hypoxia conditions,whereas the protein expression was increased dramaticaly.The mRNA and protein expression of VEGF was significantly increased under hypoxia and minic hypoxia conditions.The positive rate of HIF-1?mRNA(90%)and VEGF(100%)in 20 fresh frozen tissues were higher than those of the para-tumor tissues(P

Objective To investigate expression levels of epithelial mucin 1 (MUC1) and epitbelial mucin15(MUC15) in elderly patients with papillary thyroid carcinoma and assess the role of MUC1 and MUC15 in the pathogenesis of thyroid papillary carcinoma.Methods Protein expression of MUC1 and MUC15 was detected by immunohistochemistry in 10 samples from normal thyroid tissue adjacent to thyroid adenoma,57 samples from papillary thyroid carcinoma (PTC),and 14 samples from PTC in neck lymph node metastasis.Results Expression rates of MUC1 in normal thyroid tissues,thyroid papillary carcinoma,and lymph node metastatic carcinoma were 40.0％,75.4％,64.3,respectively,and the rates for MUC15 were 0,73.7％,71.4％,respectively.The positive expression rate of MUC1 was higher in PTC tissues than in normal thyroid tissues (x2 =5.10,P=0.02) and,compared with normal thyroid tissues,the positive expression rate of MUC15 increased in PTC tissues and lymph node metastatic carcinoma (x2 =12.25 and 19.75,both P＜0.05)MUC15 protein expression was higher in micro-PTC (less than or equal to 1 cm in diameter) than in carcinoma larger than 1 cm in diameter (90.9％ vs.62.9,x2 =5.48,P=0.02).MUC15 expression was higher in PTC without lymph node metastasis than in PTC with lymph node metastasis (83.8％vs.55.0％,x2 =5.55,P=0.02).MUC1 expression was positively correlated with MUC15 expression in thyroid papillary carcinoma (r=0.35,P=0.01).Conclusions MUC1 and MUC15 may have synergistic effects in the initiation and progression of PTC.MUC15 may play a role in regulating tumorigenesis of thyroid papillary carcinoma in early stages and can potentially serve as a supplementary marker in the screening of micro-thyroid papillary carcinoma.

Objective To investigate the necessity of low-intensity anticoagulation standard in patients after heart valve replacement and the rationality of INR in our hospital.Methods 681 eligible candidates were anticoagulated under the current guidelines for postoperative anticoagulation therapy in our hospital(AVR 1.5-2.0,MVR 2.0-2.5,DVR 2.0-2.5,TVR 2.5-3.0).We monitored the patient 's PT regularly and analyzed the occurrence of anticoagulation-related complications,such as bleeding,thrombosis and embolism.Results 602 cases completed the follow-up.During the period of follow-up,66 patients had bleeding tendencies,the incidence of bleeding complications was 10.96％ (66/602).1 1 patients had embolism complications,the incidence of thrombotic complications was 1.83 ％ (11/602).The average of INR was 2.24± 0.68,the mean oral Warfarin dose was(3.12± 1.14) mg/d.Conclusion Our study suggest that the effect of low-intensity anticoagulation after heart valve replacement is reliable.Further more,the current anticoagulation standards of our hospital meet the requirements of postoperative clinical anticoagulant after heart valve replacement in our region.

Objective To study the changes of behavior and depression-like classic indicators after hippocampal microinjection of K252a,and to establish a new animal model of depression.Methods SD rats were randomly divided into five groups,namely the control group,sham group,chronic stress depression model group,hippocampal of K252a microinjection group,and hippocampal microinjection K252a plus chronic stress group.Open field experiments,sucrose consumption test,and Morris water maze behavioral assay were used to assess the behavioral changes in the rats.ELISA was used to detect the plasma monoamine neurotransmitter,radioimmunoassay was used to determine the plasma CRH,ACTH,CORT contents,and western-blotting was performed to observe the protein expression of BDNF,CREB,ERK1/2,and BCL-2 in the hippocampus.Results Compared with the control group,the amount of activity,sugar consumption,learning and memory abilities were decreased(P<0.05 or P<0.01),also the serum monoamine neurotransmitters were decreased (P<0.01),HPA axis function was improved (P<0.01),and the expression of BDNF,CREB,ERK1/2,BCL-2 decreased in the CUMS group(P<0.05 or P<0.01),but there was no significant difference in the DMSO group.Compared with the DMSO group,the activity,consumption of sucrose,learning and memory ability were significantly decreased(P<0.05 or P<0.01),while the HPA axis function was increased (P<0.05 or P<0.01),the serum monoamine neurotransmitters decreased(P<0.05 or P<0.01),and the BDNF,CREB,ERK1/2,BCL-2 expressions in the hypocampus were significantly decreased(P<0.05 or P<0.01) in the K252a group and K252a + CUMS group.Compared with the CUMS group,the K252a group and K252a + CUMS group did not show significant changes in these parameters.Compared with the K252a group,these indicators were not significantly changed in the K252a + CUMS group.Conclusions The results of behavior,hematology,and molecular biology analysis show that this model has a great similarity to the classical model of CUMS in surface validity,construct validity,and functional validity.It may provide an alternative investigative technology platform for basic research and antidepressant drug screening.