Functional characterization of porcine nucleophosmin (NPM1) gene in promoting the replication of Japanese encephalitis virus and induction of inflammatory cytokines.

Nucleophosmin (NPM1) is a multifunctional nucleolar protein that plays a role in cell cycle control, tumorigenesis, induction of the inflammatory cytokine, virus replication, as well as the cellular responses to a variety of stress stimuli. However, its physiological functions in pigs have not been well understood. Here, we cloned the porcine NPM1 (porNPM1) gene and analyzed the functions of the porNPM1 protein in pigs. The full-length porNPM1 gene encoded a 294-amino acid protein with 94.5%-99.3% sequence identity to its orthologues in mammals and was extensively expressed in various pig tissues at the mRNA level. The porNPM1 primarily localizes in the nucleus of ST cells, while it translocates from the nucleus to nucleoplasm upon UV irradiation or H2O2 treatment. Notably, JEV infection blocked the translocation of porNPM1 from the nucleolus to the nucleoplasm. Furthermore, porNPM1 interacted with the JEV C protein and facilitated JEV replication in ST cells. The overexpression and knockdown of porNPM1 respectively enhanced or impaired JEV replication, suggesting the important role of porNPM1 in JEV replication. Additionally, the purified ectodomain of porNPM1 induced the production of inflammatory cytokines (TNF-α, IL-6, and IL-8). Together, these data demonstrated that porNPM1 is involved in cellular stress stimuli, JEV replication, and induction of inflammatory cytokines.

[Effects of topical application of doxycycline on avulsed permanent teeth].

PURPOSE: To evaluate the treatment effect of topical doxycycline on avulsed permanent teeth compared with normal saline. METHODS: A total of 44 avulsed teeth from 38 patients (22 boys and 16 girls, aged 7-14 years) were recruited. Twenty-one teeth in group A were treated with doxycycline for 5 min before replantation while 23 teeth in group B were treated with saline solution. All participants were followed up for at least 12 months. The clinical outcome differences between 2 groups was evaluated by Mann-Whitney U test. RESULTS: In group A, 18 teeth were found pulp necrosis, 3 with infection-related resorption, 13 with ankylosis-related resorption and 6 were extracted. In group B, 16 were diagnosed with pulp necrosis, 4 with infection-related resorption, 12 with ankylosis-related resorption and 7 were extracted. No significant differences were found between the two groups on pulp survival and periodontal healing. CONCLUSIONS: Compared with treatment with normal saline, avulsed permanent teeth treated with doxycycline did not show a better clinical outcome.

[Micro-CT study of root canal morphology of mandibular first premolars with multi-canals].

PURPOSE: To observe root canal system of multi-canal mandibular first premolars and to analyze the morphology of them by micro-CT and three-dimensional reconstruction. METHODS: Thirty-two extracted mandibular first premolars with multiple root canals were selected and scanned by micro-CT. The number and morphology of canals, location of bifurcation and 5 subtle structures (lateral canals, apical ramification, isthmus, loops, apical delta) were analyzed. RESULTS: In the 32 specimens, 96.88% contained radicular depressions or grooves. The canal configuration was type II, Ⅲ, Ⅴ: 3.12%, type Ⅳ: 31.25%, type Ⅷ: 9.38%, type Ⅸ: 15.62% and C-shaped canal: 34.38% by Vertucci's classification. 62.50% of the canals bifurcated at the middle third of roots, comparing with 37.50% at apical third. The incidence of the lateral canals, apical ramification, isthmus, loops and apical delta was 56.25%, 43.75%, 40.62%, 21.88% and 6.25%, respectively, which were all found at the middle and apical third of roots except that lateral canals were found at all depth of canals. CONCLUSIONS: Most mandibular first premolars with multiple canals contain radicular depression or grooves, of which root canal system are complicated. Micro-CT can provide clear and accurate three-dimensional information of canal morphology.

[Elimination of Entercoccus faecalis with different disinfection methods in root canals in vitro].

PURPOSE: To compare the elimination effect against E.faecalis in root canals with different methods. METHODS: Fifty extracted premolars with single root canal were selected. After cleaning and autoclaving, they were contaminated by E.faecalis and incubated for 28 days as models. Then the models were randomly and equally divided into 5 groups and treated as below: specimens in group A were treated with saline irrigation, specimens in group B were treated with 3% NaClO irrigation (as positive control), specimens in group C were treated with PUI, specimens in group D were treated with diode laser radiation, specimens in group E were treated with combination of PUI and diode laser radiation. The specimens from root canals were collected by paper points. The bacterial suspensions were later serially diluted and plated on tryptic soy agar plates to enumerate the CFUs after 48 hours. Statistical analysis was performed using SAS 8.02 software package. RESULTS: As with all parts of the root canal in aggregate, the CFUs of the specimens treated with PUI, diode laser radiation and the combination of them were significantly lower than the specimens treated with saline irrigation (P<0.01), but there was no significant difference among 3 groups (P>0.05). However, the specimens treated with 3% NaClO irrigation had the best effect of disinfection. The number of CFUs in the specimens treated with 3% NaClO was almost zero. There was no significant difference between this group and others in CFUs(P<0.01). CONCLUSIONS: Specimens treated with PUI, diode laser radiation and the combination of them showed great effect of elimination against biofilm of Enterococcus faecalis compared with saline irrigation. Irrigation with 3% NaClO was the most efficient method in this experiment.