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Objective:To investigate the disinfection effectiveness of photodynamic therapy (PDT) combined with ethylenediaminetetraacetic acid (EDTA) disodium salt solution on enterococcus faecalis in lateral root canals.Methods:Sixty-four human single root canal premolars were selected to prepare artificial root canal collaterals, and E. faecalisin root canal collateral infection models were established. The infection model was divided into PDT group ( n=16), PDT combined with EDTA group ( n=16), positive control group ( n=16) and negative control group ( n=16) according to random number table method. In the PDT group, 40 μg/ml hematoporphyrin monomethyl ether was injected into the root canal, and then the root canal was irradiated with a 45 mW laser for 90 s after 5 min incubation. In the PDT combined with EDTA group, the root canal was given 5 ml EDTA solution with 17% mass fraction for 1 min, and then treated with the method same as the PDT group. In the positive control group, the root canal were given 5 ml NaClO solution with a mass fraction of 5.25 % for 1 min. In the negative control group, the root canal were given NaCl solution with a mass concentration of 9 g/L for 1 min. Before and after the treatments, samples were taken in the lateral branches of the root canal with a K file to count plate colonies. After treatments, the roots of each group were placed in sterile brain heart infusion broth (BHI) medium for anaerobic culture for 24 h, and then sampled with a K file, and the number of root canal collaterals was detected statistically. Scanning electron microscopy was used to observe the morphology of the inner wall of lateral branches of root canals after treatments. Results:The sterilization rate of PDT combined with EDTA group was 99.56%, which was significantly higher than that of negative control group (1.98%), positive control group (85.87%) and PDT group (87.53%), the differences were statistically significant (all P<0.05). The reply experiment shows that the number of infection root canals was only 5, which was less than the negative control group (15), positive control group (12) and PDT group (11), and the differences were statistically significant (all P<0.05). Scanning electron microscopy observations showed that no obvious E. faecalis adhered to the inner wall of root canal of PDT combined with EDTA group. Conclusions:PDT combined with EDTA has a good disinfection effectiveness on E. faecalis in lateral canals, and it is expected to provide a new method for the effective killing of E. faecalis in lateral canals in clinical root canal therapy.
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Objective@#To observe the clinical and electrophysiological characteristics of botulinum toxin A poisoning induced by local cosmetic injection, and to explore the possible pathogenesis.@*Methods@#Clinical data of 20 patients with botulinum toxin type A local cosmetic injection poisoning admitted to our hospital from January 2016 to December 2018 were collected and electrophysiological tests were carried out.@*Results@#The clinical manifestations of 20 patients were mainly 15/20 (75.0%) with limb weakness, and the proximal end was heavier than the distal 20/20 (100%), and the upper limb was heavier than the lower limb 26/20 (80%), followed by dysphagia 12/20 (60%), dysarthria 5/20 (25%), cervical muscle weakness 5/20 (25%), extraocular muscle paralysis 4/20 (20%), masseter muscle weakness 3/20 (15%) and respiratory muscle weakness 2/20 (5.0%) with respiratory failure 1/20 (5.0%). The results of neurophysiological examination showed the highest rate of SFEMG (90.0%), followed by RNS (80.0%), EMG (65.0%) and NCV (40.0%), suggesting that neuromuscular junction dysfunction was the main presentation. Patients who actively gave botulinum antitoxin injection therapy and symptomatic support treatment had good prognosis.@*Conclusions@#Local cosmetic injection of botulinum toxin type A may lead to poisoning. The symptoms of poisoning are mainly caused by limb weakness. Neuroelectrophysiological examination can assist in the diagnosis of botulinum toxin poisoning.
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Objective To study the effects of pulsed Nd:YAG laser radiation on the marginal microleakage of porcelain-fused-to-metal crowns. Methods Twenty in vitro premolar teeth were selected and processed by standard porcelain crown preparation. The porcelain-fused-to-metal crowns were made based on the relevant repair technical requirements. The restorations were randomly divided into control group (group A) and experimental group (group B). The restorations in the group B were treated by external Nd:YAG laser irradiation with power of 1.25 W and irradiation time of 20 s. All the restorations were fixed with composite resin cement, and then put into normal saline under 37℃for 20 d, during which 300 times thermal cycling were performed. After that, the restorations were placed into 0.5％ pinkish red solution for 24 hours to dyeing, and then dissected along the longitudinal axis. The marginal microleakage of the restoration was observed by a stereomicroscopy. The data were processed by the SPSS 19.0 software. Results The degree of marginal microleakage of the restorations after Nd:YAG laser irradiation was significantly lower than that in the control group (P<0.05). Conclusions The pulsed Nd:YAG laser irradiation can effectively improve the adhesion between the resin and the hard tissue of the teeth, and reduce the marginal microleakage of the porcelain-fused-to-metal crowns.
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Photodynamic therapy (PDT) has been wildly used in the treatment of tumors and dermatologic diseases,especially,when the traditional therapies are ineffective or bring side effects.Moreover,with the deepening of the studies,its effects in anti-microbial has been found.PDT in the treatment of infectious diseases has attracted more and more attention of scholars.In this review,we discussed the mechanism of the PDT,studies in the sterilization of a variety of oral pathogenic bacteria by the PDT and its potential applications in clinic.
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Objective To investigate the effects of 17?-estradiol (E2) on the gene expression of typeⅠA bone morphogenetic protein receptor (BMPR-ⅠA) and core-binding factor alpha 1 (Cbf?1) in rat bone marrow stromal cells exposed to the differentiation medium and to elucidate the effects of E2 on osteoblastogenesis. Methods Adherent bone marrow stromal cells were cultured in differentiation medium containing DEX (10 -7 mol/L), 1,25-(OH)2D3 (10 -9 mol/L) and different concentrations of E2. Effects of different concentrations of E2 on the gene expression of BMPR-ⅠA and Cbf?1 was quantified by RT-PCR based on the comparison with an internal reference, ?-actin expression, and identified by Northern blotting. Alkaline phosphatase (ALP) activity of cells was detected. Contents of type Ⅰ collagen were determined by Van Gieson staining. Results E2 could evidently inhibit the expression of BMPR-ⅠA and Cbf?1 mRNA during the differentiation process of bone marrow stromal cells into osteoblasts in a dose-dependent manner. These were confirmed by Northern blotting. The ALP activity increased in a concentration-dependent manner, but the amount of type Ⅰ collagen decreased in a concentration-dependent manner. Conclusion E2 can significantly inhibit the gene expression of BMPR-ⅠA and Cbf?1 in bone marrow stromal cells and inhibit osteoblastogenesis in vitro.
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AIM:To investigate the effect of different oxygen concentrations on the differentiation of marrow stroma cells into osteoblasts and to evaluate the expression of Cbf?1 /Runx2,bone-morphogenesis protein 2 (BMP2) and peroxisome proliferator-activated receptor ?2 (PPAR-?2) in bone marrow stromal cells. METHODS:The bone marrow stomal cells obtained from 4-month-old female SD rats were cultured in growth medium and were used between passages 3 to 5. The cells were divided randomly into 4 groups,each group has 8 samples. The cells in all 4 groups were used for the following experiments after cultured with different oxygen concentrations for 3 d in osteoblastic differentiation medium:total cellular RNA was isolated using total RNA kit; RT -PCR was performed to detect the mRNA expression of Cbf?1 /Runx2,BMP2 and PPAR?2. The protein expression of Cbf?1 /Runx2 and BMP2 was assayed by Western blotting. RESULTS:Compared to the cells in normoxia condition (20% ),the mRNA and protein expressions of Runx2 were enhanced significantly,the mRNA expression of BMP2 was also enhanced significantly,the protein expression of BMP2 increased and the mRNA expression of PPAR?2 decreased significantly in the cells cultured with lower oxygen concentrations. The lower oxygen con-centration was in the culture,the more Runx2 mRNA,BMP2 mRNA,BMP2 and Runx2 protein were expressed. On the contrary,hypoxia significantly decreased the expression of PPAR?2 mRNA in bone marrow stronmal cells and the lower the oxy-gen concentration was used,the less expression of PPAR?2 mRNA was achieved. CONCLUSION:Hypoxia promotes the mRNA and protein expressions of Runx2 and BMP2,also significantly decreases the expression of PPAR?2 mRNA in bone marrow stronmal cells in an oxygen concentration dependent manner,indicating that hypoxia significantly stimulates the differentiation of bone marrow stromal cells into osteoblasts instead of lipocytes.
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AIM:To investigate the effects of 17?-estradiol (E_2) on the gene expression of typeⅠA and typeⅠB bone morphogenetic protein receptor (BMPR-ⅠA,ⅠB) in rat bone marrow stromal cells exposured to the differentiation medium and to elucidate the effects of E_2 on osteoblastogenesis. METHODS: Adherent bone marrow stromal cells were cultured in differentiation medium containing DEX(10 -7 mol?L -1 ) and 1,25(OH)_2D_3 (10 -9 mol?L -1 ) and different concentrations of E_2. The gene expression of BMPR-ⅠA,ⅠB was quantified by semiquantitative RT-PCR. RESULTS: E_2 evidently inhibited the expression of BMPR-ⅠA mRNA in bone marrow stromal cells.The suppression was dose-dependent. When examined under various concentrations of E_2 (0-10 -6 mol?L -1 ),the expression of BMPR-ⅠA mRNA were decreased from (25.7?2.5)% to(16.3?1.5)%( P
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Osteoprotegerin(OPG) ,receptoractivatorofNF -?Bligand (RANKL)andreceptoracti vatorofNF -??(RANK)areimportantmoleculesthatregulateosteoclastogenesis .OPGisdecoyreceptorof RANKL .ThebindingofOPGandRANKLblocksconnectingofRANKLandRANK ,inhibitsdevelopmentof osteoclast.ThebindingofRANKLandRANKinducesaserieskinasecascadereaction ,activatestranscription factors,introducestheproliferationanddifferentiationofosteoclastprecursors .Severalhormonesandos teotropicfactorsregulatetheformationandfunctionofosteoclastthroughtheabovemolecules .
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Thirty percent TBSA full thickness burns due to napalm was inflicted to the rats and the pathological changes of the thyroid were studied under optical and electron microscopy and with peroxidase histochemistry for 15 days. The alterations of serum T3 and T4 levels accompaniying the pathological changes were also observed dynamically.It was found that the pathological changes of the thyroid could be distinguished into three phases as follows.1. The phase of injury inhibition. This phase existed from the 2nd to the 24th hour postburn and was characterized by marked damage on the follicular epithelium.2. The phase of structural and functional recovery. This phase entended from the 3rd to the 6th day postburn. In this phase, the damages on the thyroid became abated and its damaged structure showed a tendency to recover.3. The phase of active function. It extended from the 10th to the 15th day postburn. The organelles to synthesize and release thyroid hormone were fonud well developed.The alteration of T4 run parallelly to the pathological changes of the thyroid in all the stages, while T3 level was continously inhibited because of the lower serum concentration of T4, the metabolic disturbance of T4 deiodination, and the inhibition of thyroid secretion in the early postburn stage and the metabolic disturbance of T4 deiodination in the middle and late postburn stages. In the early postburn stage, the inhibition of thyroid peroxidase was an important factor of functional inhibition of the thyroid.