ABSTRACT
The abnormality of ubiquitin proteasome pathway is an important factor leading to the imbalance of protein homeostasis. In this process, the deubiquitinase responsible for removing the ubiquitin chain of protein substrate is very important. Its abnormal activity or expression can cause the functional changes of key oncogenic/tumor suppressor proteins, which directly or indirectly lead to the occurrence, development and malignant evolution of tumors. Based on this, the discovery and research of small molecule inhibitors targeting deubiquitinases have become a hot field of anti-tumor candidate drugs. This review will focus on the regulatory effect and mechanism of ubiquitin proteasome pathway, especially deubiquitinase on tumor, introduce the application of deubiquitinase small molecule inhibitors in tumor treatment, and discuss the research status and latest progress of small molecule inhibitors, so as to provide ideas for the research of new anti-tumor strategies based on deubiquitinase.
ABSTRACT
AIM:To investigate the effects of titanium dioxide(TiO2)nanotube arrays on the early adhesion behavior of Porphyromonas gingivalis(Pg),Tannerella forsythia(Tf)and Actinobacillus actinomycetemcomitans(Aa)be-fore and after loaded with minocycline hydrochloride(MN).METHODS: TiO2nanotube arrays were prepared by ano-dization and loaded with MN.Titanium slices were divided into 3 groups according to different treatment methods: pure polishing titanium(Ti)group,TiO2nanotube titanium(TiO2)group, and MN(120 μg)TiO2nanotube titanium(MN TiO2)group.The antibacterial properties of the titanium tablets were evaluated by the bacteriostasis test.RESULTS:The Ti had no antibacterial activity.The antibacterial activity of TiO 2to Aa,Pg and Tf was poor,with only about 20%of anti-bacterial rate after 4 h.After loaded with MN,its antibacterial activity was enhanced,and the antibacterial rate was up to 77%after 4 h.CONCLUSION: No antibacterial activity in the Ti group was observed.If TiO2nanotube arrays were formed on the surface and MN was loaded,the antibacterial activity on periodontal pathogens was stronger.
ABSTRACT
<p><b>OBJECTIVE</b>Using chitosan (CS)/beta-tricalcium phosphate (TCP)/recombinant human bone morphogenetic protein (rhBMP)-2 for the reconstruction of rabbits' mandible defect, to prove the feasibility of CS/beta-TCP as an injectable bone tissue engineering scaffold material.</p><p><b>METHODS</b>Twenty-four New Zealand white rabbits were randomized into 4 groups on average: Experimental group 1 embedding CS/beta-TCP/rhBMP-2, experimental group 2 embedding CS/ beta-TCP, control group 1 embedding autograft bone group, control group 2 embedding nothing. At 2, 4 and 8 weeks after surgery, all rabbits were executed group by group. The new bone growth situations were observed with hematoxylin-eosin staining and immunofluorescence microscopy, the bone mineral density was detected by bone sonometers.</p><p><b>RESULTS</b>After 2, 4, 8 weeks, there was significant difference among the areas of bone regeneration of all groups. The effect of experimental group 1 was better than experimental group 2. There was significant difference at different times, the areas of bone regeneration was gradually increased with time. The area of stained yellow in experimental group 1 was larger, the area of stained red was smaller. The quantities of bone density in experimental group 1 at every time after surgery were significantly higher than experimental group 1 and control group 2, but had no statistical significance with control group 1.</p><p><b>CONCLUSION</b>CS/beta-TCP/rhBMP-2 has good biocompatibility, degradability and the capacity of guided and inducing osteogenesis. CS/beta-TCP as a good injection of carrier could become a promising carrier for rhBMP-2 and potential new degradable biological material for repairing bone defect in clinical application.</p>
Subject(s)
Animals , Humans , Rabbits , Bone Morphogenetic Protein 2 , Bone Morphogenetic Proteins , Bone Regeneration , Bone Transplantation , Bone and Bones , Calcium Phosphates , Chitosan , Osteogenesis , Recombinant Proteins , Tissue Engineering , Tissue Scaffolds , Transforming Growth Factor betaABSTRACT
<p><b>OBJECTIVE</b>To explore the possibility of pulsed Nd:YAG laser-aided debonding for removing orthodontic metal brackets and to compare the method with the conventional mechanical debonding method.</p><p><b>METHODS</b>Fifty healthy premolars extracted for orthodontic purpose were randomly divided into five groups (10 teeth in each group). There were four experimental groups and one control group. Every tooth was bonded with bracket. Laser was used to irradiate the teeth in experimental groups with different electric currents (13.0, 13.5, 14.0, 14.5 A). During the irradiation, the brackets received 4.9 N of force until the brackets off. The time needed for debonding and the temperature change of the pulp cavity were recorded. The teeth in control group were debonded using mechanical method. The adhesive remnant index (ARI) was calculated using stereomicroscope and imagetool software. All samples were examined with a scanning electron microscope.</p><p><b>RESULTS</b>The time taken between the four groups were (67.70 ± 7.18), (35.90 ± 4.28), (24.90 ± 3.76), (6.90 ± 2.33) s, highly statistical difference was found in the time needed for debonding (P < 0.01). The temperature in the pulp cavity among the four groups were (20.97 ± 3.10), (12.75 ± 3.14), (8.99 ± 2.47), (2.91 ± 1.88)°C, and statistical differences were found in temperature change of the pulp cavity (P < 0.05). ARI of three experimental groups and the control group were (8.55 ± 5.02)%, (15.42 ± 7.37)%, (5.55 ± 3.79)%, (13.72 ± 6.69)%, and (74.36 ± 29.44)%. The enamel surface of the control group was coarse with deep scratchs. The enamel surface was smooth and clean in the experimental groups.</p><p><b>CONCLUSIONS</b>Pulsed Nd:YAG laser-aided debonding for removing metal brackets was feasible. Laser-aided debonding was better than conventional mechanical debonding method. The method reduced the damage to the enamel surface.</p>