The clinical characteristics of neuronal intranuclear inclusion disease and its relation with inflammation.

BACKGROUND: Neuronal intranuclear inclusion disease (NIID) is a great imitator with a broad spectrum of clinical manifestations that include dementia, parkinsonism, paroxysmal symptoms, peripheral neuropathy, and autonomic dysfunction. Hence, it may also masquerade as other diseases such as Alzheimer's disease, Parkinson's disease, and Charcot-Marie-Tooth disease. Recent breakthroughs on neuroimaging, skin biopsy, and genetic testing have facilitated the diagnosis. However, early identification and effective treatment are still difficult in cases of NIID. OBJECTIVE: To further study the clinical characteristics of NIID and investigate the relationship between NIID and inflammation. METHODS: We systematically evaluated the clinical symptoms, signs, MRI and electromyographical findings, and pathological characteristics of 20 NIID patients with abnormal GGC repeats in the NOTCH2NLC gene. Some inflammatory factors in the patients were also studied. RESULTS: Paroxysmal symptoms such as paroxysmal encephalopathy, stroke-like episodes, and mitochondrial encephalomyopathy lactic acidosis and stroke (MELAS)-like episode were the most common phenotypes. Other symptoms such as cognitive dysfunction, neurogenic bladder, tremor, and vision disorders were also suggestive of NIID. Interestingly, not all patients showed apparent diffusion-weighted imaging (DWI) abnormality or intranuclear inclusions, while abnormal GGC repeats of NOTCH2NLC were seen in all patients. And fevers were noticed in some patients during encephalitic episodes, usually with increasing leukocyte counts and neutrophil ratios. Both IL-6 (p = 0.019) and TNF-α (p = 0.027) levels were significantly higher in the NIID group than in normal controls. CONCLUSION: Genetic testing of NOTCH2NLC may be the best choice in the diagnosis of NIID. Inflammation might be involved in the pathogenesis of NIID.

A comparative study of dentinal tubule penetration and the retreatability of EndoSequence BC Sealer HiFlow, iRoot SP, and AH Plus with different obturation techniques.

OBJECTIVES: This study aimed to evaluate dentinal tubule penetration and the retreatability of EndoSequence BC Sealer HiFlow (HiFlow), iRoot SP, and AH Plus when using the single-cone (SC) or continuous wave condensation (CWC) technique. MATERIALS AND METHODS: Sixty-five single-rooted teeth were instrumented and randomly divided into 5 groups: group 1, AH Plus/CWC; group 2, iRoot SP/CWC; group 3, iRoot SP/SC; group 4, HiFlow/CWC; and group 5, HiFlow/SC. The ability to re-establish patency during endodontic retreatment was recorded, as was the time taken to reach the working length. Dentinal tubule penetration and remaining debris after retreatment were evaluated by confocal microscopy and scanning electron microscopy. Data were analyzed by Kruskal-Wallis test and Dunn's multiple comparisons test (α = 0.05). RESULTS: The HiFlow/CWC and iRoot SP/CWC groups required more time to reach the working length than groups that underwent the SC technique regardless of the sealer used (P < .05). The HiFlow/CWC group showed a significantly higher percentage of sealer penetration area than that of the iRoot SP/SC at 4 mm from the apex (P < .05) and penetrated deeper into dentinal tubules than iRoot SP/SC at both 8-mm and 12-mm levels (P < .05). Moreover, the HiFlow/CWC and HiFlow/SC groups demonstrated less remaining sealer along the canal wall than AH Plus/CWC group at 4-mm level (P < .05). CONCLUSIONS: HiFlow/CWC technique showed better performance in dentinal tubule penetration than that of iRoot SP/SC. Both HiFlow and iRoot SP combined with CWC technique groups required more retreatment time than the other groups. Furthermore, using HiFlow with either the CWC or SC technique left less remaining sealer at 4-mm level than using AH Plus with the CWC technique during retreatment. CLINICAL RELEVANCE: With favorable performance in dentinal tubule penetration and retreatability in endodontic retreatment, the combined use of EndoSequence BC Sealer HiFlow with the recommended continuous wave condensation technique may be a worthwhile choice in root canal treatment.

Metabolic profiling of RB-2 and RB-4, two analogs of polyacetylene from Bupleurum.

RB-2 and RB-4 are two structural analogs of polyacetylene from Radix Bupleuri that show antidepressant effects. However, no metabolic data are available to elucidate their systemic homeostasis. Mass spectrometry combined with liver microsomes and recombinant drug-metabolizing enzymes were performed to profile the biotransformations of RB-2/RB-4 in vitro and in vivo. Oxidation should be the major metabolic pathways for them in phase I, while CYP2C9 and CYP2E1 was the major contributor. In phase II, conjugational groups usually combined with the metabolites from phase I. This study provides an important reference basis for the safety evaluation and rational application of RB-2/RB-4.

Dental Follicle Stem Cells Ameliorate Lipopolysaccharide-Induced Inflammation by Secreting TGF-ß3 and TSP-1 to Elicit Macrophage M2 Polarization.

BACKGROUND/AIMS: Increasing evidence has demonstrated the novel roles of mesenchymal stem cells (MSCs) in immunotherapy. However, difficulty in acquiring these cells and possible ethical issues limited their application. Recently, we have isolated a unique MSC population from dental follicles with potent stem cell-like properties. This study focused on the effects of dental follicle stem cells (DFSCs) on macrophage activation and polarization to determine their role in immunomodulation and to test if DFSCs are a promising cell source for MSC-based immunotherapy. METHODS: Rat acute lung injury (ALI) models induced by Lipopolysaccharide (LPS) were applied to test the immune-modulatory effects of DFSC/DFSC-CM in vivo. The pulmonary permeability was determined by the dry / wet weight ratios of the left upper lung lobe. The lung histopathological damage was graded on a 0 to 4+ scale. And the inflammatory cytokines in bronchoalveolar lavage fluid (BALF) were tested by ELISA. Then we established LPS-induced inflamed macrophage models in vitro. Inflammatory cytokine production and polarization marker expression were measured by RT-qPCR, ELISA, western blot and flow cytometric analysis in macrophages following DFSC-CM treatment. The paracrine factors in DFSC-CM were revealed by a RayBiotech Protein Array. Thereafter, neutralization studies were performed to confirm the potential immune regulators in DFSC-CM. RESULTS: The DFSC/DFSC-CM not only attenuated histopathological damage and pulmonary permeability, but also downregulated pro-inflammatory cytokines MCP-1, IL-1, IL-6 and TNF-α, and upregulated anti-inflammatory cytokine IL-10 in BALF. Immunofluorescence staining revealed the increased expression of macrophage M2 marker Arg-1. Further in vitro study revealed that macrophages switched to an anti-inflammatory M2 phenotype when co-cultured with DFSC-CM, characterized by suppressed production of pro-inflammatory cytokines MCP-1, IL-1, IL-6, TNF-α and M1-polarizing markers iNOS and CD86; and increased expression of the anti-inflammatory cytokine IL-10 and the M2-polarizing markers Arg-1 and CD163. A RayBiotech Protein Array revealed 42 differentially expressed (> 2-fold) paracrine factors in DFSC-CM compared with the serum-free Ham's F-12K medium, among which TGF-ß3 and Thrombospondin-1 (TSP-1) were upregulated by 18- and 105-fold, respectively. Neutralization studies confirmed the immunoregulatory roles of TGF-ß3 and TSP-1 in macrophage activation and polarization. CONCLUSION: These results indicated that DFSCs can reprogram macrophages into the anti-inflammatory M2 phenotype, the paracrine factors TGF-ß3 and TSP-1 may be one of the underlying mechanisms. This study supports the hypothesis that DFSCs are promising for MSC-based immunotherapy.

Reference ranges for atlantodental interval in adults and its variation with age and gender in a large series of subjects on multidetector computed tomography.

BACKGROUND: The atlanto-dental interval measurement in the cervical spine in young adults has been reported on multidetector computed tomography (MDCT), but has not been systematically assessed in all ages. PURPOSE: To evaluate the reference ranges for the atlanto-dental interval (ADI) in a large sample of adult patients on MDCT and to analyze the relationships of these measurements with gender and age of the patients as well as inter-observer performance. MATERIAL AND METHODS: First, a consecutive series of 700 Chinese patients aged over 18 years undergoing an upper cervical MDCT scan were divided equally into seven age groups. Second, the mid-sagittal image of the atlanto-dental joint was chosen for measurement and ADI was defined as the distance intercepted from the segment line linking the center of anterior atlas tubercle with that of posterior tubercle. Third, the correlation of ADI with age and gender was analyzed using linear regression analysis. Finally, the inter-observer performance was assessed using Bland and Altman's limits of agreement. RESULTS: The ADI was 1.77 ± 0.39 mm, 1.61 ± 0.37 mm, 1.58 ± 0.36 mm, 1.41 ± 0.29 mm, 1.31 ± 0.29 mm, 1.34 ± 0.28 mm, and 1.06 ± 0.47 mm in the age groups 18-24 years, 25-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, and older than 70 years, respectively. The range of ADI was 0.85-3.12 mm in the age group 18-39 years, 0.71-2.55 mm in the age group 40-59 years, and 0.00-2.37 mm in the age group older than 60 years. There was no difference between gender and ADI (r = 0.00, P = 1.000). ADI decreased linearly with age (r = -0.511, P = 0.000). The inter-observer performance was reliable. CONCLUSION: ADI measurements on MDCT linearly decrease with increasing age, and these are not affected by gender in adult patients. Different reference values might be used at different ages when diagnosing atlantoaxial anterior dislocation or subluxation.

A ROS-responsive hydrogel incorporated with dental follicle stem cell-derived small extracellular vesicles promotes dental pulp repair by ameliorating oxidative stress.

Pulpitis, an inflammatory disease of dental pulp tissues, ultimately results in the loss of pulp defense properties. Existing clinical modalities cannot effectively promote inflamed pulp repair. Oxidative stress is a major obstacle inhibiting pulp repair. Due to their powerful antioxidative capacity, mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) exhibit potential for treating oxidative stress-related disorders. However, whether MSC-sEVs shield dental pulp tissues from oxidative damage is largely unknown. Here, we showed that dental follicle stem cell-derived sEVs (DFSC-sEVs) have antioxidative and prohealing effects on a rat LPS-induced pulpitis model by enhancing the survival, proliferation and odontogenesis of H2O2-injured dental pulp stem cells (DPSCs). Additionally, DFSC-sEVs restored the oxidative/antioxidative balance in DPSC mitochondria and had comparable effects on ameliorating mitochondrial dysfunction with the mitochondrion-targeted antioxidant Mito-Tempo. To improve the efficacy of DFSC-sEVs, we fabricated an intelligent and injectable hydrogel to release DFSC-sEVs by combining sodium alginate (SA) and the ROS sensor RhB-AC. The newly formed SA-RhB hydrogel efficiently encapsulates DFSC-sEVs and exhibits controlled release of DFSC-sEVs in a HClO/ClO- concentration-dependent manner, providing a synergistic antioxidant effect with DFSC-sEVs. These results suggest that DFSC-sEVs-loaded SA-RhB is a promising minimally invasive treatment for pulpitis by enhancing tissue repair in the pulp wound microenvironment.

Self-assembly of differentiated dental pulp stem cells facilitates spheroid human dental organoid formation and prevascularization.

BACKGROUND: The self-assembly of solid organs from stem cells has the potential to greatly expand the applicability of regenerative medicine. Stem cells can self-organise into microsized organ units, partially modelling tissue function and regeneration. Dental pulp organoids have been used to recapitulate the processes of tooth development and related diseases. However, the lack of vasculature limits the utility of dental pulp organoids. AIM: To improve survival and aid in recovery after stem cell transplantation, we demonstrated the three-dimensional (3D) self-assembly of adult stem cell-human dental pulp stem cells (hDPSCs) and endothelial cells (ECs) into a novel type of spheroid-shaped dental pulp organoid in vitro under hypoxia and conditioned medium (CM). METHODS: During culture, primary hDPSCs were induced to differentiate into ECs by exposing them to a hypoxic environment and CM. The hypoxic pretreated hDPSCs were then mixed with ECs at specific ratios and conditioned in a 3D environment to produce prevascularized dental pulp organoids. The biological characteristics of the organoids were analysed, and the regulatory pathways associated with angiogenesis were studied. RESULTS: The combination of these two agents resulted in prevascularized human dental pulp organoids (Vorganoids) that more closely resembled dental pulp tissue in terms of morphology and function. Single-cell RNA sequencing of dental pulp tissue and RNA sequencing of Vorganoids were integrated to analyse key regulatory pathways associated with angiogenesis. The biomarkers forkhead box protein O1 and fibroblast growth factor 2 were identified to be involved in the regulation of Vorganoids. CONCLUSION: In this innovative study, we effectively established an in vitro model of Vorganoids and used it to elucidate new mechanisms of angiogenesis during regeneration, facilitating the development of clinical treatment strategies.

Sheath-core structured Ca-alginate/PVA aerogel fibers via directed freezing wet-spinning.

Biomass-based aerogel fibers have attracted increasing attention due to their renewable nature. However, their disadvantages, such as low mechanical strength, poor long-range order, and easy combustion, are still significant challenges. Herein, a directed freezing-assisted forced stretching strategy is developed to fabricate sheath-core structured Ca-alginate/polyvinyl alcohol (Ca-A/PVA) aerogel fibers with Long-range-ordered pores. The Ca-A/PVA aerogel fibers (3:2 m/m) exhibit the best comprehensive mechanical properties in terms of low thermal conductivity of 0.0524 W·m-1·K-1, a density of 0.1614 g·cm-3, a porosity of 89.9 %, a tensile strength of 8.72 MPa, a tensile modulus of 249.7 MPa, a toughness of 1.98 MJ∙m-3, and a self-extinguishing time from the fire of <1.2 s. The Ca-A/PVA fabrics showed a maximum absolute temperature difference of 11.4 °C at -20 °C and 14.0 °C at 60 °C compared to the plate temperature. The presented strategy is generalizable to other alginate-based aerogel fibers (e.g., alginate/guar gum).

Small extracellular vesicles derived from hypoxic preconditioned dental pulp stem cells ameliorate inflammatory osteolysis by modulating macrophage polarization and osteoclastogenesis.

Extensive macrophage inflammatory responses and osteoclast formation are predominant during inflammatory or infective osteolysis. Mesenchymal stem cell (MSC)-derived small extracellular vesicles (MSC-sEV) have been shown to exert therapeutic effects on bone defects. However, cultured MSCs are typically exposed to normoxia (21% O2) in vitro, which differs largely from the oxygen concentration in vivo under hypoxic conditions. It is largely unknown whether sEV derived from dental pulp stem cells (DPSCs) cultured under hypoxic conditions (Hypo-sEV) exert better therapeutic effects on lipopolysaccharide (LPS)-induced inflammatory osteolysis than those cultured under normoxic conditions (Nor-sEV) by simultaneously inhibiting the macrophage inflammatory response and osteoclastogenesis. In this study, we show that hypoxia significantly induces the release of sEV from DPSCs. Moreover, Hypo-sEV exhibit significantly improved efficacy in promoting M2 macrophage polarization and suppressing osteoclast formation to alleviate LPS-induced inflammatory calvarial bone loss compared with Nor-sEV. Mechanistically, hypoxia preconditioning markedly alters the miRNA profiles of DPSC-sEV. MiR-210-3p is enriched in Hypo-sEV, and can simultaneously induce M2 macrophage generation and inhibit osteoclastogenesis by targeting NF-κB1 p105, which attenuates osteolysis. Our study suggests a promising potential for hypoxia-induced DPSC-sEV to treat inflammatory or infective osteolysis and identifies a novel role of miR-210-3p in concurrently hindering osteoclastogenesis and macrophage inflammatory response by inhibiting NF-kB1 expression.

SrCuSi4 O10 /GelMA Composite Hydrogel-Mediated Vital Pulp Therapy: Integrating Antibacterial Property and Enhanced Pulp Regeneration Activity.

Vital pulp therapy (VPT) is considered a conservative treatment for preserving pulp viability in caries-induced dental pulp infections. However, bacterial contamination negatively affects dentine-pulp complex repair. The common capping materials show limited antimicrobial effects against some microorganisms. To improve the VPT efficacy, capping materials with increased antibacterial properties and enhanced odontogenic and angiogenic activities are needed. Herein, a SrCuSi4 O10 /gelatin methacrylate(SC/Gel) composite hydrogel has been proposed for infected dental pulp treatment. SrCuSi4 O10 (SC) is a microscale bioceramic composed of assembled multilayered nanosheets that possesses good near-infrared photothermal conversion ability and multiple bioactivities due to sustained Sr2+ , Cu2+ , and SiO3 2- ion release. It is shown that the SC/Gel composite hydrogel efficiently eliminates Streptococcus mutans and Lactobacillus casei and inhibits biofilm formation under photothermal heating, while the ion extract from SC promotes odontogenesis of rat dental pulp stem cells and angiogenesis of human umbilical vein endothelial cells. The as-designed therapeutic effect of SC/Gel composite hydrogel-mediated VPT has been proven in a rat dental pulp infection model and yielded improved dentine-pulp complex repair compared with the commercially used iRoot® BP Plus. This study suggests that the SC/Gel composite hydrogel is a potential pulp-capping material with improved effects on dentine-pulp complex repair in infected pulp.

Modulating and optimizing Pluronic F-68 concentrations and feeding for intensified perfusion Chinese hamster ovary cell cultures.

Perfusion culture is often performed with micro-sparger to fulfill the high oxygen demand from the densified cells. Protective additive Pluronic F-68 (PF-68) is widely used to mitigate the adverse effect in cell viability from micro-sparging. In this study, different PF-68 retention ratio in alternating tangential filtration (ATF) columns was found to be crucial for cell performance of different perfusion culture modes. The PF-68 in the perfusion medium was found retained inside the bioreactor when exchanged through ATF hollow fibers with a small pore size (50 kD). The accumulated PF-68 could provide sufficient protection for cells under micro-sparging. On the other hand, with large-pore-size (0.2 µm) hollow fibers, PF-68 could pass through the ATF filtration membranes with little retention, and consequently led to compromised cell growth. To overcome the defect, a PF-68 feeding strategy was designed and successfully verified on promoting cell growth with different Chinese hamster ovary (CHO) cell lines. With PF-68 feeding, enhancements were observed in both viable cell densities (20%-30%) and productivity (~30%). A threshold PF-68 concentration of 5 g/L for high-density cell culture (up to 100 × 106 cells/mL) was also proposed and verified. The additional PF-68 feeding was not observed to affect product qualities. By designing the PF-68 concentration of perfusion medium to or higher than the threshold level, a similar cell growth enhancement was also achieved. This study systematically investigated the protecting role of PF-68 in intensified CHO cell cultures, shedding a light on the optimization of perfusion cultures through the control of protective additives.

[Growth and migration of umbilical cord mesenchymal stem cells on polycarbonate membrane with different pore sizes].

OBJECTIVE: To observe the growth and migration of human umbilical cord mesenchymal stem cells (hUCMSCs) on polycarbonate membrane with different pore sizes and explore the criteria of selecting optimal Transwell insert for indirect co-culture to induce the differentiation of hUCMSCs. METHODS: hUCMSCs were isolated in vitro and then expanded in culture medium. After the treatment of mitomycin C, the cells were seeded on porous membranes of 6-well-dish Transwell inserts with different pore sizes of 0.4, 3.0 and 8.0 µm respectively. After culturing for 7 days, the cells were observed and counted on the bottom of each porous membrane. Then the calculation of migration ratio was performed. The growth and migration of hUCMSCs on porous membranes were also examined under scanning electron microscope (SEM). RESULTS: The migration ratios of hUCMSCs on membranes of 0.4, 3.0 and 8.0 µm pore sizes were 0, 1.8% and 8.0% respectively. The migration ratio of cells on 0.4 µm pore size membrane was statistically different from that of the other two pore size groups (P < 0.01). Under SEM, a small portion of cells were growing on the bottoms of membranes and moving through the pores. But there was no cell movement through 0.4 µm pore size membrane. CONCLUSIONS: hUCMSCs can migrate through the polycarbonate membranes of 3.0 µm and 8.0 µm pore sizes but not through the 0.4 µm one. Thus both sides of polycarbonate membrane of 0.4 µm pore size may be used for close indirect co-culture to induce the differentiation of hUCMSCs.

LPS-induced autophagy in human dental pulp cells is associated with p38.

Lipopolysaccharides (LPS), which are components of the cell wall of Gram-negative bacteria, are among the important factors that induce inflammation, including pulpitis. Autophagy in human dental pulp cells (hDPCs) acts as a protective mechanism that promotes cell survival under adverse conditions through different signaling pathways. In this study, we examined whether LPS increases autophagy in hDPCs and investigated the role of mitogen-activated protein kinases signaling and nuclear factor κB (NF-κB) in this process. We found that stimulation of hDPCs with 0.1 µg/mL LPS increased the protein and mRNA levels of autophagy markers, beclin1 and microtubule associated protein light chain 3II (LC3II). In addition, acridine orange staining and transmission electron microscopy demonstrated the induction of autophagy upon the treatment of LPS. Furthermore, LPS affected phosphorylation of p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK), and the nuclear translocation of NF-κB. While p38 inhibitor suppressed the LPS-induced increase in protein levels of beclin1 and LC3-II. Our results suggest that LPS induced autophagy in hDPCs and affected the phosphorylation of p38, ERK, and JNK, as well as the nuclear translocation of NF-κB. Phosphorylation of p38 may be involved in LPS-induced autophagy in hDPCs.

Primary clinical study of radiomics for diagnosing simple bone cyst of the jaw.

OBJECTIVE: To screen the radiomic features of simple bone cysts of the jaws and explore the potential application of radiomics in pre-operative diagnosis of jaw simple bone cysts. METHODS: The investigators designed and implemented a case-control study. 19 patients with simple bone cysts who were admitted to the Department of Maxillofacial Surgery, Sun Yat-sen University Affiliated Stomatology Hospital from 2013 to 2019 were included in this study. Their clinical data and cone-beam computed tomography (CBCT) images were examined. The control group consisted of patients with odontogenic keratocyst. CBCT imaging features were analyzed and compared between the patient and control groups. RESULTS: Overall, 10,323 image features were extracted through feature analysis. A subset of 25 radiomic features obtained after feature selection were analyzed further. These 25 features were significantly different between the 2 groups (p < 0.05). The absolute value of correlation coefficient was 0.487-0.775. Gray-level co-occurrence matrix (GLCM) contrast, neighborhood gray tone difference matrix (NGTDM) contrast, and GLCM variance were the features with the highest correlation coefficients. CONCLUSIONS: Pre-operative radiomics analysis showed the differences between simple bone cysts and odontogenic keratocysts, can help to diagnose simple bone cysts. Three specific texture features-GLCM contrast, NGTDM contrast, and GLCM variance-may be the characteristic imaging features of simple bone cysts of the jaw.

Syntheses of click PEG-dexamethasone conjugates for the treatment of rheumatoid arthritis.

A novel linear multifunctional polyethylene glycol (PEG)-dexamethasone (Dex) conjugate (click PEG-Dex) was synthesized using facile Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition (a click reaction). Dex was conjugated to the click PEG via an acid-labile hydrazone bond to allow the drug release in a pathophysiological environment. To evaluate click PEG's potential as a versatile drug delivery platform, the click PEG-Dex conjugates were tested in an adjuvant-induced arthritis (AA) rat model. In vivo optical imaging data confirmed the arthrotropism of the conjugates in the arthritic rats. A long-term treatment study revealed that a single click PEG-Dex conjugate administration provided sustained (>15 days) amelioration of ankle joint inflammation to the AA rats. Treatment with an equivalent dose of dexamethasone phosphate sodium (free Dex) only provided temporal resolution of the arthritis, which recurred upon treatment withdrawal. Further histological and bone mineral density comparison between the ankle joints from both click PEG-Dex and free Dex treatment groups confirmed the superior anti-inflammatory and disease modifying effects of the novel polymer-drug conjugates.

Light-responsive vesicles for enantioselective release of chiral drugs prepared from a supra-amphiphilic M-helix.

A kind of light-responsive vesicle was prepared by aqueous self-assembly of α-CD and an azobenzene-containing M-helical foldamer, which displayed dynamic disassembly-reassembly structural transformation when alternately irradiated by UV and visible light. Distinctively, this vesicle also exhibited enantioselective release abilities toward racemic propranolol (a ß-blocker), owing to the M-helical building blocks.

[Application of three-dimensional CT and image classification in percutaneous vertebraplasty for osteoporotic vertebral compression fractures].

OBJECTIVE: To explore the application of three-dimensional CT and image classification in the treatment of osteoporotic vertebral compression fracture(OVCFs) by percutaneous vertebroplasty(PVP). METHODS: A total of 90 patients with OVCFs who were treated with PVP in Linqu People's Hospital of Shandong Province from April 2016 to March 2018 were selected as subjects. There were 31 males and 59 females, aged from 63 to 84 years old. Bone mineral density measurements were performed in all patients to confirm the presence of osteoporosis and imaging examinations were performed to confirm the presence of vertebral fractures. The fracture area was determined by MRI fat surpressed image before operation and three-dimensional modeling was performed to calculate the volume of fracture area. Three dimensional CT imaging of bone cement in fracture area was performed after PVP and the volume ratio of bone cement in fracture area was calculated by computer aided design software, by which patients were divided into groups for study. Forty-one patients whose volume ratio of bone cement in fracture area less than 50% are control group and the rest of 90 patients are observation group. Visual analogue scale (VAS) and Oswestry Disability Index(ODI) were collected in two groups before operation and 1 day, 3 months after operation. The amount of bone cement was recorded after operation. RESULTS: All operations were successful. There were 3 cases of cement leakage in control group and 4 cases in observation group. All patients had no obvious clinical symptoms. After continuous observation and follow-up for 3 months, no complications such as adjacent vertebral fracture, infection, bone cement displacement were found. There was no significant difference in bone cement doses and bone cement leakage between two groups(P>0.05). There was no significant difference in preoperative VAS and ODI between two groups(P>0.05). All VAS and ODI obviously decreased(P<0.05) at 1 day after operation and in observation group the decrease was more significant (P<0.05). At 3 months after operation there was no significant difference between two groups. This may have been due to basically healing of vertebral fractures at 3 months after surgery and the pain was no longer significantly related. CONCLUSIONS: PVP can significantly improve clinical symptoms of OVCFs and bone cement filling in fracture area is the key to the short-term effect of PVP.

Biomimetic Pulsating Vesicles with Both pH-Tunable Membrane Permeability and Light-Triggered Disassembly-Re-assembly Behaviors Prepared by Supra-Amphiphilic Helices.

The reversible unfolding-refolding transition is considerably important for natural elastomeric proteins (e.g., titin) to fulfill their biological functions. It is of great importance to develop synthetic versions by borrowing their unique stretchable design principles. Herein, we present a novel pulsating vesicle by means of the aqueous self-assembly of supra-amphiphilic helices. Interestingly, this vesicle simultaneously features dynamic swelling and shrinkage movements in response to external proton triggers. Titin-like unfolding-refolding transformation of artificial helices was proved to play a crucial role in this pulsatile motion. Moreover, the vesicular membrane of this vesicle has exhibited tunable permeability during reversible expansion and contraction circulation. Meanwhile, light can also be used as a driving force to further regulate the disassembly-reassembly transformation of the pulsating vesicle. In addition, the drug delivery system was also employed as an investigating model to estimate the permeability variation and disassembly-reassembly behaviors of the pulsating vesicles, which displayed unique dual quick- and sustained-release behaviors toward anti-cancer agents. It is anticipated that this work opens an avenue for fabricating novel stretchable biomimetics by using the exclusive unfolding-refolding nature of artificial foldamers.

[Preparation of a biodegradable drug-eluting stent in myocardium channel].

OBJECTIVE: To prepare a biodegradable drug-eluting stent in myocardium channel and evaluate its effect on myocardium channel after transmyocardial revascularization (TMR). METHODS: A biodegradable drug-eluting stent was prepared using poly (epsilon-caprolactone) (PCL), bovine serum albumin (BSA), and poly (D, L-lactide-co-glycolide) (PLGA) as material of stent, model protein drug, and drug carrier respectively. The amount of BSA in stent and in vitro released BSA of stent were determined by the Coomassie brilliant blue assay. The mechanical strength of stent was tested by universal material testing machines. The material and structure of stent was characterized by nuclear magnetic resonance spectroscopy. The effect of stent on myocardium channel after TMR was evaluated in vivo by a standard animal model of chronic myocardial ischemia in miniswine. RESULTS: The stent could carry 13.1 microg BSA per mg of stent and the stent could release about 95% of BSA after 30 days. The stent diminished 80% of initial scale under the stress of 1.7 Mpa. It also kept the myocardium channel patency after TMR. CONCLUSIONS: A biodegradable drug-eluting stent in myocardium channel was successfully prepared. It can sustain the pressure from the heart and achieve the controlled release of drug. The stent can ensure the myocardium channel patency after TMR.

[Current situation of clinical research on impacted premolars].

Teeth impaction is a common developmental malformation in oral diseases. Impacted teeth are usually the canines, third molar, central incisors, premolars, and second molars. The prevalence of impaction of maxillary canines and mandibular wisdom teeth is higher than that of other teeth. Most recent studies have focused on the canines and third molars, but research on impacted premolars is limited. In clinical practice, the majority of orthodontic patients require premolar extraction. Thus, impacted premolars play important roles in orthodontic design and prognosis. This article provides an overview of recent research on impacted premolars and summarizes epidemiological features, localizations, and treatments, with the aim of guiding practitioners on orthodontic design and therapy.