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 explore the effects of estrogen and angiotensin Ⅱ receptor 1 inhibitor（saralasin）on cell proliferation,cell cycle and apoptosis in endometrial carcinoma cell line HEC-1A.Methods Immunocytochemical assay was applied to detect the expression of AT1-R,PI3K,p-Akt and ERK protein in HEC-1A cell.The effects of estrogen and saralasin on cell proliferation,cell cycle distribution and apoptosis of HEC-1A cell were detected by MTT assay and fluorescence activated cell sorting technique.The expression of ERK and p-Akt protein in HEC-1A cell treated with estrogen and saralasin were analyzed by Western blot.Results The expression of AT1-R,PI3K,pAkt,and ERK protein was found in HEC-1A cell.Estrogen stimulated the proliferation of HEC-1A cell,decreased G0~G1 phase proportion and increased S phase proportion significantly,minimized the number of apoptotic cells,and up-regulated the expression of ERK protein.Saralasin obviously inhibited the proliferation and induced apoptosis of estrogen induced HEC-1A cell,increased G0~G1 phase proportion and decreased S phase proportion,and down-regulated the expression of ERK protein.Conclusion Estrogen could promote the proliferation of HEC-1A cell through AT1-R.AT1-R inhibitor saralasin could inhibit the proliferation and induce the apoptosis of estrogen induced HEC-1A cell.The down-regulation of ERK protein expression by interrupting the mitogen-activated protein kinase（MAPK）signaling pathway might be involved in the possible mechanism.Thus saralasin could be a valid approach to treat ER-negative endometrial carcinoma.

Objective To observe the ultrasonographic features of local chest wall tumor recurrence after mastectomy for breast cancer and its clinical and histopathological characteristics. Methods The ultrasonographic features, clinical and histopathological characteristics of 27 patients with local chest wall tumor recurrence after mastectomy confirmed histopathologically were retrospectively reviewed. Results The disease-free intervals of twenty-seven patients ranged from 3 to 129 months [mean (31.9±31.4) months]. Most of the recurrence(18/27, 66.7%) occurred within 3 years after mastectomy. The clinical manifestations were:7 cases (7/27, 25.9%) with regional skin redness and swelling, red rash or ulceration on chest wall associated with or without palpable mass, 20 cases(20/27, 74.1%) with chest wall palpable masses without obvious skin change. On ultrasonography, 2 cases showed diffuse inifltrative type with ill-deifned inhomogeneous hypoechoic lesion and skin thickening. And twenty-ifve cases(43 lesions) showed mass type with a lesion size range of 5.4-114.7 mm [mean (24.4±21.6) mm]. Among them, 32 lesions were located near to the operation incision scar, 36 involved muscle layer, 38 were hypoechoic, 31 had irregular shape, 24 had indistinct margin, and 31 had blood lfow signal. In addition, calciifcation, halo, and taller-than-wide shape were absent in all 43 lesions. Conclusions The tumor recurrence often occurred within 3 years after mastectomy in high-risk patients. Ultrasonographic feature of chest wall recurrent lesion is of great value in the diagnosis.

Compared with open surgery, laparoscopic surgery (LS) provides distinct advantages. However, LS is limited because of the lack of flexibility and tactile feedback. These drawbacks may result in prolonged learning curve and increase in difficulty of sur-gery, particularly for reconstructive LS. This study aimed to determine more efficient methods and resolve several limitations, such as surgical education, LS, surgical procedures (suturing and knotting), iconography, and biotechnology in LS. This review provides a broad overview of studies related to this field.

Objective To discuss the characteristics and management of pregnancy on cesarean section scar. Methods Five women with pregnancy on cesarean section scar were reviewed from Apr. 2000 to Mar. 2003. Results All of the five patients had cesarean section before and suffered from painless,irregular vaginal bleeding after 6～8 weeks of amenorrhea. The pregnancy could be misdiagnosed as invasive mole or cervical pregnancy. All had better outcome by uterine suction under ultrasound monitoring without massive bleeding or hysterectomy. Conclusions Women who had cesarean section before are in the risk of pregnancy on the old scar. Clear diagnosis should be made before any treatment. Ultrasound monitoring,local MTX injection and packing can be utilized to prevent perforation during suction. Patients should be monitored continuously after operation with serum hCG level and ultrasound. The principle prevention of pregnancy on cesarean section scar is to reduce the cesarean section rate and effective contraception.

Objective To investigate the expression of HPV-DNA and p16,Ki-67 proteins in intraepithelial lesion of cervix (CIN) so as to provide the aluable evidence for the early clinical diagnosis and genetic therapy of the CIN.Methods Hybrid capture2 was used to detect HPV DNA in 35 cases of CIN Ⅰ,44 cases of CIN Ⅱ,and 20 cases of CIN Ⅲ.Immunohistochemical MaxVision was used to research the expression of p16 and Ki-67 protein in CIN Ⅰ,CIN Ⅱ and CIN Ⅲ.The results were analyzed with clinicopathological factors.Results Positive expression rates of HPV-DNA were 31.4 ％ (11/35),63.6 ％ (28/44),85.0 ％ (17/20) in CIN Ⅰ,CIN Ⅱ and CIN Ⅲ,respectively.The expression rates of p16 in the three groups were 65.7 ％ (23/35),97.7 ％ (43/44),100.0 ％ (20/20),there were statistically significant difference (x2 =21.30,P =0.00).The expression rates of Ki-67 in the three groups were 77.1％ (27/35),79.5 ％ (35/44),95.0 ％ (19/20),there were no difference (x2 =3.00,P =0.22).Conclusions HPV infection is closely related to the occurrence and development of CIN.p16,Ki-67 can be used as objective marks in diagnosis of CIN.

Objective To investigate the effect and mechanism of epigallocatechin-3-gallate(EGCG) on intestine ischemia reperfusion injury(IRI) in rats. Methods Forty SD rats were randomly and equally divided into 4 groups:sham group(Sham),intestinal ischemia reperfusion injury group(IRI),EGCG pretreatment group(EGCG) and HLY78 group (Wnt-Ag).The IRI,EGCG and WNT-AG groups were performed the superior mesenteric artery(SMA) ligation for 45 min by non-injury vascular clamp to construct the IRI model.EGCG (50 mg/kg) was administrated by intraperitoneal injection at 45 min before ischemia in EGCG group.The Wnt-Ag group was administrated by intraperitoneal injection of EGCG(50 mg/kg) plus Wnt-Ag (5 mg/kg) at 45 min before ischemia.The IRI group and Sham group were administrated by same dosage of normal saline.The pathological morphology of intestinal tissue was observed by staining at 4 h after reperfusion.The cellular apoptosis was detected by immunohistochemistry.The expressions of tumor necrosis factor-α(TNF-α),interleukin-1(IL-1),interleukin-6(IL-6) in the serum and intestinal tract were examined by ELISA and RT-PCR.The expressions of Wnt,β-catenin,p53,Bax and BCL-2 were measured by Western blot.Results Compared with the Sham group,the expression of IL-6,IL-1,TNF-α,Wnt,β-catenin,Bax,cell apoptosis and pathological change of intestinal tract in the IRI group were significantly increased,while the expression of BCL-2 was significantly decreased.Compared with the IRI group,the expression of IL-6,IL-1,TNF-α,Wnt,β-catenin,p53,Bax,cell apoptosis and the pathological change of intestinal tracrt in the EGCG group were significantly decreased,while the expression of BCL-2 was significantly increased.Compared with the EGCG group,the expression of IL-6,IL-1,TNF-α,Wnt,β-catenin,Bax,cell apoptosis and pathological change of intestinal tract in the Wnt-Ag group were increased,while the expression of BCL-2 was significantly decreased.Conclusion EGCG can alleviate intestine ischemia-reperfusion injury by suppressing inflammation and apoptosis,this protective effect may be mediated by suppressing Wnt/β-catenin signal pathway.

Objective To study the influence of carboxymethyl-chitosan(CM-chitosan)on chondro- cyte apoptosis induced by recombinant human interleukin-1?(rhIL-1?)and explore its mechanism.Methods Rabbit chondrocytes were isolated and cultured.Chondrocytes were pretreated with different concentrations of CM-chitosan for 1 h,then 10 ng/ml IL-1?were added into the culture medium.After 24 h,the apoptotic rates of chondrocytes were measured by flow cytometry with AnnexinⅤ-FITC and PI staining.The morphology of nuclei was observed by fluorescent microscopy with Hoechst 33342 staining.The mitochondrial membrane po- tentials were tested by confocal laser scanning microsocopy with Rhodamine-123 and ATP contents were mea- sured by luciferase reaction.Results CM-chitosan could inhibit chondrocyte apoptosis and restore the func- tion of mitochondria induced by IL-113 in a dose-dependent manner.Conclusion CM-ehitosan can inhibit chondrocyte apoptosis by protecting mitochondrial function.

Rotavirus capsid protein Vp4 plays an important role in the virus adhering and entering the cells. In this study, a Vp4 gene cloned from a rotavirus strain TB-Chen was highly expressed in E.coli BL21 (DE3). The results of the Western blot showed that the protein possesses specific immuno-reactivities and can be specifically recognized by guinea pig antibodies against rotavirus strain SA11 or Wa. Some Vp4 dimers were formed during renaturation. These data obtained from this study provide a strong basis for further study on the structure and function of the Vp4.

Objective To investigate the effects of Pulmicort Respules on the airway resistance and airway remodeling in rats with allergic asthma. Methods Thirty-two SD rats were randomly divided into blank control group,asthma model group,Pulmicort Respules group and normal saline control group,with 8 rats in each group.On the 14th day of allergization,rats were challenged by ovalbumin inhalation and were treated correspondingly.On the 28th day,airway resistance was determined,HE staining was conducted in lung tissues of each group,and airway remodeling related parameters were also measured. Results The airway resistance of Pulmicort Respules group was significant lower than that of blank control group,asthma model group and normal saline control group(P