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.

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 .

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.

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

The effects of angiotensin II receptor antagonist losartan on elastic properties of aorta in patients with mild to moderate essential hypertension were assessed. The ascending aortic distensibility in 26 patients (48 +/- 3 years) with mild to moderate essential hypertension before and after 12 weeks of treatment with losartan (50 mg/day) was evaluated by using two-dimensional echocardiography. M-mode measurements of aortic systolic (Ds) and diastolic diameter (Dd) were taken at a level approximately 3 cm above the aortic valve. Simultaneously, cuff brachial artery systolic (SBP) and diastolic (DBP) pressures were measured. Aortic pressure-strain elastic modulus (Ep) was calculated as Dd x (SBP-DBP)/(Ds-Dd) x 1333 and stiffness index beta (beta) was defined as Dd x Ln (SBP/DBP)/(Ds-Dd). Blood pressure significantly decreased from 148 +/- 13/95 +/- 9 mmHg to 138 +/- 12/88 +/- 8 mmHg (systolic blood pressure, P = 0.001; diastolic blood pressure, P = 0.003). There was no significant difference in pulse pressure before and after treatment with losartan (53 +/- 10 mmHg vs 50 +/- 7 mmHg). The distensibility of ascending aorta increased significantly as showed by the significant decrease in pressure-strain elastic modulus from 4.42 +/- 5.79 x 10(6) dynes/cm2 to 1.99 +/- 1.49 x 10(6) dynes/cm2 (P = 0.02) and stiffness index beta from 27.4 +/- 32.9 to 13.3 +/- 9.9 (P = 0.02). Although there was a weak correlation between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in diastolic blood pressure after losartan treatment (r = 0.40, P = 0.04 and r = 0.55, P = 0.004, respectively), no correlation was found between the percent changes in pressure-strain elastic modulus and stiffness index beta and that in systolic blood pressure (r = 0.04, P = 0.8 and r = 0.24, P = 0.2, respectively). Our study demonstrated that angiotensin II receptor antagonist losartan has a beneficial effect on aortic distensibility in patients with mild to moderate essential hypertension and this effect is partly independent of blood pressure reduction.
Aorta/*physiopathology ; Aorta/ultrasonography ; Echocardiography ; Elasticity ; Hypertension/*drug therapy ; Hypertension/*physiopathology ; Hypertension/ultrasonography ; Losartan/*therapeutic use ; Receptors, Angiotensin/*antagonists & inhibitors

To assess the left ventricular regional relaxation abnormalities in patients with hypertrophic cardiomyopathy (HCM) by quantitative tissue velocity imaging (QTVI), Doppler echocardiography and QTVI were performed in HCM (n=10) and healthy subjects (n=11) at apical long-axis, two-chamber and four-chamber views. Regional early diastolic velocity (rVe) and regional atrial contraction (rVa) were measured at each segment of ventricular middle, basal and annular levels. Mean rVe and mean rVa at three levels as well as mean rVe/rVa ratio were calculated. Our results showed that transmitral inflow peak velocities during early diastole (E) and atrial contraction (A) were also measured and E/A ratio was calculated. The rVe of all left ventricular segments in HCM were lower than those in healthy subjects (P<0.05), but compared with healthy subjects majority of rVa in HCM were not different except inferior wall and anterior wall. E between HCM and healthy subjects was different (P=0.036), while mean rVe between them was significantly different (P<0.0001). Mean rVa and mean rVe/rVa of three levels were lower in HCM than in healthy subjects (P<0.05), but there were no differences in A and E/A between them (P=0.22, P=0.101). Left ventricular regional myocardial relaxation is reduced in HCM. Transmitral inflow E and A are influenced by preload, relaxation of myocardium and atrial contraction, etc., while rVe and rVa reflect myocardial relaxation function independently. QTVI is more sensitive and more accurate than conventional Doppler imaging for characterizingregional diastolic properties in HCM.
Cardiomyopathy, Hypertrophic/*physiopathology ; Cardiomyopathy, Hypertrophic/*ultrasonography ; Diastole ; Echocardiography, Doppler, Color/methods ; Hypertrophy, Left Ventricular/*physiopathology ; Hypertrophy, Left Ventricular/ultrasonography ; Ventricular Function, Left

To explore the feasibility of using tissue Doppler imaging technique for the evaluation of fetus's left ventricular diastolic function, and to confirm its reliability by comparing it with traditional methods, this study examined 61 pregnant women in whom satisfactory images were obtained of fetal echocardiography. The peak velocity of blood stream were measured, including E, A and E/A at mitral valve orifice on the four chamber view with pulse wave. And then tissue Doppler imaging mode was employed to measure the velocity of mitral valve annulus including Ea, Aa, Sa and Ea / Aa. Correlation analysis was conducted between the velocity of orifice and that of annulus in terms of gestation age. And then correlation analysis was performed between above data and gestation ages. A positive correlation was found between the velocity of orifice and that of annulus, and the velocity increased with the gestation age. The change was the most significant between the 28th and the 34th week of gestation age. Our study showed that it is feasible to evaluate the fetus's left ventricular diastole function by tissue Doppler imaging. Its stability can avoid the influence of fetal heart rates and preload.