Restoration of teeth after removal of previous restorations is a common problem in the dental clinic. The situation of teeth after removal of previous restoration is complex and often requires multidisciplinary cooperation. However, there is a lack of systematic and concise guidelines for determining the treatment plan for those teeth. Through a combination of restorative clinical experience and the opinions of endodontic specialists, the author systematically described the problems that may exist after the removal of previous restorations in the teeth that have not undergone or have undergone root canal treatment (RCT) and those with post and core restorations. And summarized the corresponding treatment recommendations according to their pulpal and periapical status, the quality of RCT and the presence or absence of post and core restorations. ①For teeth without RCT, the vitality of the pulp, the occurrence of pulpal/periapical disease and the amount of re-preparation need to be assessed to determine whether RCT is necessary. ②For teeth with RCT, if the quality of RCT is good and no periradicular lesion exists, direct restorative treatment can be considered. If the quality of the RCT is unsatisfactory but no periradicular lesion exists, root canal retreatent (re-RCT), follow up or direct restorative treatment should be performed as appropriate and treatment plan can be developed in conjunction with the endodontist if necessary. If the quality of the RCT is unsatisfactory and periradicular lesion exists, re-RCT is necessary before restorative treatment.③For teeth with post and core restorations, if the quality of RCT is good and no periradicular lesion exists, direct restorative treatment can be considered. If the quality of the RCT is unsatisfactory but no periradicular lesion exists, follow up or direct restorative treatment should be performed as appropriate and treatment plan can be developed in conjunction with the endodontist if necessary. If the quality of RCT is unsatisfactory and periradicular lesion exists, for teeth with thin post and thick root canal walls, re-RCT after removal of the post can be attempted. For teeth with thick post and thin root canal walls, preservation of the post and apical surgery can be considered. For the teeth with excessively large defects or extremely poor periodontal conditions, extraction is recommended. The author refined the above recommendations into a set of treatment procedures, aiming to provide a reference for the selection of treatment options for teeth after removal of previous restorations.

Bacillus cereus belongs to Gram-positive bacteria, which is widely distributed in nature and shows certain pathogenicity. Different B. cereus strains carry different subsets of virulence factors, which directly determine the difference in their pathogenicity. It is therefore important to study the distribution of virulence factors and the biological activity of specific toxins for precise prevention and control of B. cereus infection. In this study, the hemolysin BL triayl was expressed, purified, and characterized. The results showed that the bovine pathogenic B. cereus hemolysin BL could be expressed and purified in the prokaryotic expression system, and the bovine pathogenic B. cereus hemolysin BL showed hemolysis, cytotoxicity, good immunogenicity and certain immune protection in mice. In this study, the recombinant expression of hemolysin BL triayl was achieved, and the biological activity of hemolysin BL of bovine pathogenic ceroid spore was investigated. This study may facilitate further investigating the pathogenic mechanism of B. cereus hemolysin BL and developing a detection method for bovine pathogenic B. cereus disease.
Cattle ; Animals ; Mice ; Bacterial Proteins/metabolism* ; Bacillus cereus/metabolism* ; Hemolysin Proteins/metabolism* ; Virulence Factors/metabolism* ; Enterotoxins/metabolism*

Escherichia coli biofilm is a complex membrane aggregation produced by the adhesion and secretion of extracellular polymeric substances by E. coli cells aggregated on specific media. Pathogenic E. coli will evade the immune system and the impact of various harmful factors in the environment after the formation of biofilm, causing sustained and even fatal damage to the host. Cyclic diguanosine monophosphate (c-di-GMP) is a second messenger ubiquitous in bacteria and plays a crucial role in regulating biofilm formation. This paper reviewed the recent studies about the role of c-di-GMP in the movement, adhesion, and EPS production mechanism of E. coli during biofilm formation, aiming to provide a basis for inhibiting E. coli biofilm from the perspective of c-di-GMP.
Bacterial Proteins/genetics* ; Biofilms ; Cyclic GMP/analogs & derivatives* ; Escherichia coli/metabolism* ; Escherichia coli Proteins/metabolism* ; Gene Expression Regulation, Bacterial

Objective:To evaluate the efficacy and safety of rituximab(RTX) as remission-mainten-ance therapy in antineutrophil cytoplasmic antibody(ANCA) associated vasculitis(AAV).Methods:Patients with AAV, including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA), treated with rituximab (RTX) in Peking Union Medical College Hospital during September 2005 to June 2021 were included into this study. Clinical data, relapse rate, time of first relapse and adverse events were collected and analyzed. The cumulative relapse rate was calculated by Kaplan-Meier, t test, and Man-Whithey U test and chi-square were used to compare differences between two groups. Results:① Thirty-nine AAV patients were enrolled, including 36 GPA and 3 MPA. During the 20(3, 104) months follow-up, 59.0%(23/39) patients had suffered relapses. The time for first relapse was 11(3, 42) months after remission. ② There were no difference in the relapse rate [60.0%(18/30) vs 55.6%(5/9), χ2=0.06, P=1.000), the time of first relapse [15(3, 42) vs 10(9, 30), Z=0.45, P=0.678], CD19 + B [23.5 (5, 148) cell/μl vs 3(2, 15) cell/μl, Z=0.57, P=0.605] and serum IgG [7.09(5.13, 13.90) g/L vs 9.72(5.32, 12.0) g/L, Z=0.36, P=0.770] between standard dose and low-dose groups. The rate of major relapse-free was significantly less in patients treated with standard dose than patients with reduced dose of RTX {87.1%[95% CI(73.4%, 100.8R%)] vs 64.3%[95% CI(23.1%, 105.4%)], χ2=7.59, P=0.006}. ③ There were no difference in relapse rate [50.0%(3/6) vs 60.6%(20/33), χ2=0.24, P=0.674], time of first relapse [23(6, 25) vs 11(3, 42), Z=0.05, P=0.982], CD19 + B[35(15, 50) cell/μl vs 10(0, 148) cell/μl, Z=0.95, P=0.382] and serum IgG[6.70(5.91, 7.49) g/L vs 7.69(3.78, 13.90) g/L, Z=0.48, P=0.700] between the fixed interval dosage and the on-demand dosage groups. There was no difference in the rate of major relapse-free between the two groups (100% vs 77.8%, χ2=1.79, P=0.181). ④ The incidence of infusion reaction was 5.1%(2/39) and infection was 20.5%(8/39). Serum IgG level was 4.37(3.78, 13.4) g/L at infection. There was no difference in safety between the standard and low-dose groups or between fixed interval and on-demand dosage groups ( P>0.05). Conclusion:There is no significant difference in relapse rate bet-ween the standard RTX dose and low-dose RTX induction therapy group, but the major relapse rate is sign-ificantly reduced in the standard dose RTX therapy. The relapse rate of fixed intervals dosage group is similar to that of on-demand dosage group. The safety profile of the standard dose and low-dose induction therapy groups or fixed intervals and on-demand dosage groups is similiar.

To investigate whether mammalian target of rapamycin (mTOR) signaling pathway is involved in peripheral nerve injury-induced hyperalgesia through activation of spinal dorsal astrocytes in rats.
 Methods: A total of 30 male Sprague-Dawley (SD) rats were randomly divided into 6 groups (n=5): the 1 day group (D1 group), the 4 days group (D4 group), the 7 days group (D7 group), the 14 days group (D14 group), the normal group and the sham group. The sciatic nerve chronic constriction injury (CCI) model was established in the D1, D4, D7 and D14 group. The normal group received no treatment while the sham group was only exposed the sciatic nerve. Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) were measured at the 1st, 4th, 7th, and 14th day after CCI in the different groups. Lumbar spinal cord were harvested on the 1st, 4th, 7th and 14th day in the D1, D4, D7, D14 group correspondingly, which were harvested on the 14th day in the normal group and the sham group. Distribution of mTOR in rat spinal cord was assessed by immunohistochemistry. The expressions of mTOR mRNA and protein in the spinal cord in different groups were determined by real-time PCR and Western blotting, respectively. Another 30 male intrathecal catheterized SD rats were randomly divided into 6 groups (n=5): a blank group, a CCI group, a CCI+early rapamycin (RAPA) group, a CCI+early dimethylsulfoxide (DMSO) group, a CCI+ later RAPA group, and a CCI+later DMSO group. The blank group didn't received any treatment; The CCI group was carried out the treatment of CCI model in the left hind limbs. 10 μL of 1% RAPA was given to the CCI+early RAPA group intrathecally at 4 hours after CCI for 3 days; the CCI+later RAPA group were treated with the same dose of RAPA on the 7th days after CCI for 3 days; the CCI+early DMSO group and the CCI+later DMSO group were injected with the same volume of 4% DMSO at the corresponding time as controls. The PWTL and PWMT were measured before and after intrathecal catheterization, and every other day after CCI. The lumbar spinal cords were selected and the expression of glial fibrillary acidic protein (GFAP) in spinal dorsal horn were examined by immunohistochemistry in the 14th day after CCI.
 Results: The immunohistochemistry positive particles of mTOR were widely distributed in the cytoplasm of the normal spinal neurons. Compared with the base line, the PWMT in the D14 group on the 1st, 4th, 7th and 14th day after CCI were significantly lower, and the PWTL on the 4th, 7th and 14th day after CCI were also significantly lower (P<0.05 or P<0.01). The expressions of mTOR mRNA and protein in the CCI groups (D1, D4, D7 and D14 group) were significantly increased than those in the normal group (P<0.05 or P<0.01). Compared with the CCI+early DMSO group, the PWMT and PWTL in the CCI+early RAPA group were obviously increased on 4th, 6th, 8th, 10th, 12th or 14th day after CCI (P<0.05 or P<0.01); compared with the CCI+later DMSO group, the PWMT and PWTL in the CCI+later RAPA group were also significantly increased at the 8th, 10th or 14th day after CCI (P<0.01 or P<0.05). The GFAP immunohistochemistry positive area and absorbance value in the dorsal horn of the lumbar spinal cord in the CCI rats were decreased in the CCI+early RAPA group compared with the CCI+early DMSO group (P<0.05 or P<0.01), and which were also decreased in the CCI+later RAPA group compared with the CCI+later DMSO group (P<0.05 or P<0.01).
 Conclusion: mTOR signaling pathway may be involved in hyperalgesia induced by peripheral nerve injury via spinal astrocyte activation in the dorsal horn of the spinal cord.
Animals ; Hyperalgesia ; Male ; Neuralgia ; Peripheral Nerve Injuries ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Spinal Cord ; TOR Serine-Threonine Kinases

OBJECTIVE: To construct the recombinant lentivirus vector containing short hairpin RNA (shRNA) inhibited DREAM expression and to investigate the gene therapy of neuropathic pain by inhibiting the expression of DREAM gene by RNA interference. METHODS: An effective short hairpin RNA targeting to rat DREAM was cloned into the plasmids on the base of Lentivirous vectors, pKCSHR-Puro/GFP, and both of the pKCSHR-Puro/GFP-DREAM and Lentivector package plasmids mix were transferred into the 293T cells. The culture supernatant was harvested, and the virus titer was detected 48 hours after transferring. Thirty-six sheer breed pathogen free adult Sprague Dawley rats were randomly divided into 6 groups (6 in each group): normal control group (N); sham-operated group (S); CCI group (C0 group):CCI model without any intervention; Saline control group (C1 group); empty vector control group (C2 group); and LV-shRNADREAM lentiviral vector treatment group (C3 group). The rats in the last 3 groups respectively accepted injection of normal saline, blank vector, LV-shRNADREAM lentiviral vector in the subarachnoid on the 7th day after CCI, and the pain behavior was observed after 3, 7, 10, 14, 21 d after CCI. Green fluorescent protein (GFP) expression was detected by fluorescence microscope and the contents of DREAM mRNA and DREAM protein were detected by Realtime PCR and Western blot respectively in the rat lumbar spinal cord. RESULTS: The short hairpin RNA sequences targeting at rat DREAM were cloned into the vectors, and an entry clone and an expression clone were constructed successfully confirmed by sequence analysis. Lentiviral packaging was successful in 293 T cell line and the transfection titer of the lentivirus was 1 x 10(8) IFU/mL. LV-shRNADREAM lentivirus vector was transfected successfully in the rat spine with Intrathecal injection of LV-shRNADREAM. Compared with the other 3 groups, heat pain threshold and mechanical pain threshold in Group C3 improved significantly (P<0.01), and the expression of DREAM mRNA and DREAM protein in the lumbar spinal cord in Group C3 were lowered significantly (P<0.01). CONCLUSION Lentivirus vectors containing rat DREAM gene are constructed successfully, and lentivirus mediated shRNA can inhibit the DREAM expression in the rat spine, which may prove to be an effective method for neuropathic pain.
Analgesia ; methods ; Animals ; Base Sequence ; Genetic Therapy ; methods ; Genetic Vectors ; genetics ; Kv Channel-Interacting Proteins ; biosynthesis ; genetics ; Lentivirus ; genetics ; metabolism ; Male ; Molecular Sequence Data ; Pain ; etiology ; Pain Management ; RNA Interference ; RNA, Small Interfering ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Repressor Proteins ; biosynthesis ; genetics ; Sciatic Nerve ; injuries ; Transfection