JiaGaSongTang improves chronic cholestasis via enhancing FXR-mediated bile acid metabolism.

BACKGROUND: Bile acid (BA) enterohepatic circulation disorders are a main feature of chronic cholestatic diseases. Promoting BA metabolism is thus a potential method of improving enterohepatic circulation disorders, and treat enterohepatic inflammation, oxidative stress and fibrosis due to cholestasis. PURPOSE: To investigate the effect of JiaGaSongTang (JGST) and its blood-absorbed ingredient 6-gingerol on α-naphthylisothiocyanate (ANIT)-induced chronic cholestasis, as well as elucidate the underlying regulatory mechanism. METHODS: Chronic cholestasis was induced in mice via subcutaneous injection of ANIT (50 mg/kg) every other day for 14 d. Treatment groups were administered JGST orally daily. Damage to the liver and intestine was observed using histopathological techniques. Biochemical techniques were employed to assess total BA (TBA) levels in the serum, liver, and ileum samples. Liquid chromatograph-mass spectrometry/mass spectrometry (LC-MS/MS) was used to analyze fecal BA components. Bioinformatic methods were adopted to screen the core targets and pathways. The blood-absorbed ingredients of JGST were scrutinized via LC-MS/MS. The effects of the major JGST ingredients on farnesoid X receptor (FXR) transactivation were validated using dual luciferase reporter genes. Lastly, the effects of the FXR inhibitor, DY268, on JGST and 6-gingerol pharmacodynamics were observed at the cellular and animal levels. RESULTS: JGST ameliorated pathological impairments in the liver and intestine, diminishing TBA levels in the serum, liver and gut. Fecal BA profiling revealed that JGST enhanced the excretion of toxic BA constituents, including deoxycholic acid. Bioinformatic analyses indicated that JGST engaged in anti-inflammatory mechanisms, attenuating collagen accumulation, and orchestrating BA metabolism via interactions with FXR and other pertinent targets. LC-MS/MS analysis identified six ingredients absorbed to the bloodstream, including 6-gingerol. Surface plasmon resonance (SPR) and dual luciferase reporter gene assays confirmed the abilities of 6-gingerol to bind to FXR and activate its transactivation. Ultimately, in both cellular and animal models, the therapeutic efficacy of JGST and 6-gingerol in chronic cholestasis was attenuated in the presence of FXR inhibitors. CONCLUSION: The findings, for the first time, demonstrated that 6-gingerol, a blood-absorbed ingredient of JGST, can activate FXR to affect BA metabolism, and thereby attenuate ANIT-induced liver and intestinal injury in chronic cholestasis mice model via inhibition of inflammation, oxidative stress, and liver fibrosis, in part in a FXR-dependent mechanism.

Tanreqing injection inhibits dengue virus encephalitis by suppressing the activation of NLRP3 inflammasome.

BACKGROUND: Encephalitis caused by dengue virus (DENV) is considered a manifestation of severe dengue. Tanreqing injection (TRQ) is a well-known Chinese patented medicine, which has been used to treat brain-related disorders by inhibiting inflammation. Nevertheless, the effects of TRQ on DENV encephalitis have not been studied. The aim of this study was to evaluate the effects of TRQ on DENV encephalitis and to explore its potential mechanisms. METHODS: The cytotoxicity of TRQ was examined by MTT assay, and the anti-DENV activities of TRQ in BHK-21 baby hamster kidney fibroblast were evaluated through CCK-8 and plaque assays. The expression levels of NO, IL1B/IL-1ß, TNFα and IL6 were measured by qRT‒PCR and ELISA in the BV2 murine microglial cell line. The inhibitory effects of TRQ on NLRP3 inflammasome activation in BV2 cells were examined by Western blotting, qRT‒PCR and ELISA. The effects of TRQ on HT22 mouse hippocampal neuronal cells were examined by CCK-8 assay, morphology observation and flow cytometry. Moreover, a DENV-infected ICR suckling mouse model was developed to investigate the protective role of TRQ in vivo. RESULTS: TRQ decreased the release of NO, IL6, TNFα and IL1B from BV2 cells and inhibited the activation of NLRP3. The presence of the NLRP3 agonist nigericin reversed the anti-inflammatory activities of TRQ. Furthermore, TRQ inhibited the death of HT22 cells by decreasing IL1B in DENV-infected BV2 cells. In addition, TRQ significantly attenuated weight loss, reduced clinical scores and extended the survival in DENV-infected ICR suckling mice. Critically, TRQ ameliorated pathological changes in ICR suckling mice brain by inhibiting microglia and NLRP3 activation and decreasing the production of inflammatory factors and the number of dead neurons. CONCLUSION: TRQ exerts potent inhibitory effects on dengue encephalitis in vitro and in vivo by reducing DENV-2-induced microglial activation and subsequently decreasing the inflammatory response, thereby protecting neurons. These findings demonstrate the potential of TRQ in the treatment of dengue encephalitis.

Liang-Ge-San: a classic traditional Chinese medicine formula, attenuates acute inflammation via targeting GSK3ß.

Sepsis is a serious life-threatening health disorder with high morbidity and mortality rates that burden the world, but there is still a lack of more effective and reliable drug treatment. Liang-Ge-San (LGS) has been shown to have anti-inflammatory effects and is a promising candidate for the treatment of sepsis. However, the anti-sepsis mechanism of LGS has still not been elucidated. In this study, a set of genes related to inflammatory chemotaxis pathways was downloaded from Encyclopedia of Genes and Genomes (KEGG) and integrated with sepsis patient information from the Gene Expression Omnibus (GEO) database to perform differential gene expression analysis. Glycogen synthase kinase-3ß (GSK-3ß) was found to be the feature gene after these important genes were examined using the three algorithms Random Forest, support vector machine recursive feature elimination (SVM-REF), and least absolute shrinkage and selection operator (LASSO), and then intersected with possible treatment targets of LGS found through the search. Upon evaluation, the receiver operating characteristic (ROC) curve of GSK-3ß indicated an important role in the pathogenesis of sepsis. Immune cell infiltration analysis suggested that GSK-3ß expression was associated with a variety of immune cells, including neutrophils and monocytes. Next, lipopolysaccharide (LPS)-induced zebrafish inflammation model and macrophage inflammation model was used to validate the mechanism of LGS. We found that LGS could protect zebrafish against a lethal challenge with LPS by down-regulating GSK-3ß mRNA expression in a dose-dependent manner, as indicated by a decreased neutrophils infiltration and reduction of inflammatory damage. The upregulated mRNA expression of GSK-3ß in LPS-induced stimulated RAW 264.7 cells also showed the same tendency of depression by LGS. Critically, LGS could induce M1 macrophage polarization to M2 through promoting GSK-3ß inactivation of phosphorylation. Taken together, we initially showed that anti-septic effects of LGS is related to the inhibition on GSK-3ß, both in vitro and in vivo.

N-rich hypercrosslinked porous polymers for highly efficient preconcentration and sensitive detection of chlorophenols.

Three novel N-rich hypercrosslinked porous polymers (NHCP1, NHCP2, and NHCP3) were facilely developed using Friedel-Crafts alkylation. NHCP1 with a remarkably large surface area (2066 m2 g-1) showed the best adsorption performance for chlorophenol pollutants. A sensitive and simple method was developed by using NHCP1 as a sorbent for solid-phase extraction to preconcentrate several chlorophenols in honey, water, and peach beverage samples followed by determination using a high-performance liquid chromatography-ultraviolet detector. The detection wavelength was 280 nm. Under the optimized conditions, the linear ranges were 1.67-1000 ng g-1 for honey, 0.170-100 ng mL-1 for water, and 0.330-100 ng mL-1 for peach beverage samples. The detection limits (S/N = 3) were 0.500-2.00 ng g-1, 0.0500-0.100 ng mL-1, and 0.100-0.200 ng mL-1, respectively. Recovery values were 89.3-111% with relative standard deviations <9.4%. The proposed extraction/preconcentration and quantitative analysis method provides an affordable and effective alternative for the preconcentration and determination of low levels of chlorophenols in real samples.

Jiawei Yanghe Decoction suppresses breast cancer by regulating immune responses via JAK2/STAT3 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Jiawei Yanghe Decoction (JWYHD) is a widely used traditional Chinese medicine prescription in the clinical setting for the treatment of autoimmune diseases. Many studies showed that JWYHD has anti-tumor activities in cell and animal models. However, the anti-breast cancer effects of JWYHD and the underlying mechanisms of action remain unknown. AIM OF STUDY: This study aimed to determine the anti-breast cancer effect and reveal the underlying mechanisms of action in vivo, in vitro and in silico. MATERIALS AND METHODS: Orthotopic xenograft breast cancer mouse model and inflammatory zebrafish model were used to observe the anti-tumor effect and immune cell regulation of JWYHD. Moreover, the anti-inflammatory effect of JWYHD were evaluated by the expression of RAW 264.7 cells. JWYHD active ingredients were obtained by UPLC-MS/MS and potential targets were screened by network pharmacology. The therapeutic targets and signaling pathways predicted by computer were assessed by Western blot, real-time PCR (RT-PCR), immunohistochemistry (IHC) staining, and Enzyme-linked immunosorbent assays (ELISA) to explore the therapeutic mechanism of JWYHD against breast cancer. At last, Colivelin and Stattic were used to explore the effect of JWYHD on JAK2/STAT3 pathway. RESULTS: JWYHD significantly decreased the tumor growth in a dose-dependent manner in the orthotopic xenograft breast cancer mouse model. Flow cytometry and IHC results indicated that JWYHD decreased the expressions of M2 macrophages and Treg while increasing M1 macrophages. Meanwhile, ELISA and Western blot results showed a decrease in IL-1ß, IL-6, TNFα, PTGS2 and VEGFα in tumor tissue of JWYHD groups. The results were also verified in LPS-induced RAW264.7 cells and zebrafish inflammatory models. TUNEL assay and IHC results showed that JWYHD significantly induced apoptosis. Seventy-two major compounds in JWYHD were identified by UPLC-MS/MS and Network pharmacology. It was found that the significant binding affinity of JWYHD to TNFα, PTGS2, EGFR, STAT3, VEGFα and their expressions were inhibited by JWYHD. IHC and Western blot analysis showed that JWYHD could decrease the expression of JAK2/STAT3 pathway. Furthermore, Colivelin could reverse the decrease effect of JWYHD in vitro. CONCLUSION: JWYHD exerts a significant anti-tumor effect mainly by inhibiting inflammation, activating immune responses and inducing apoptosis via the JAK2/STAT3 signaling pathway. Our findings provide strong pharmacological evidence for the clinical application of JWYHD in the management of breast cancer.

Quassinoids from Eurycoma longifolia with antiviral activities by inhibiting dengue virus replication.

BACKGROUND: Dengue caused by dengue virus (DENV) spreads rapidly around the world. However, there are no worldwide licensed vaccines or specific antivirals to combat DENV infection. Quassinoids are the most characteristic components of Eurycoma longifolia, which have been reported to display a variety of biological activities. However, whether quassinoids exert anti-DENV activities remains unknown. PURPOSE: To test the quassinoids of E. longifolia for their activity against DENV and to clarify the potential mechanisms. METHODS: The quassinoids from E. longifolia were isolated by chromatography techniques, and their chemical structures were elucidated by spectroscopic analysis. The anti-DENV activities of quassinoids on baby hamster kidney cells BHK-21 were determined by lactate dehydrogenase (LDH) assay. The synthesis of progeny virus was measured by plaque assay. The expression levels of envelope protein (E) and non-structural protein 1 (NS1) were evaluated by qRT-PCR, Western blot and immunofluorescence assays. Molecular docking was used to screen the potential targets of the most active quassinoid against DENV-2, and surface plasmon resonance analysis was employed to confirm the direct binding between the most active quassinoid and potential target. RESULTS: Twenty-four quassinoids, including three new quassinoids (1 - 3), were isolated from the ethanol extract of E. longifolia. Quassinoids 4, 5, 9, 11, 12, 15, 16, 17, 19 and 20 significantly reduced the LDH release at the stages of viral binding and entry or intracellular replication. Among them, 19 (6α-hydroxyeurycomalactone, 6α-HEL) exhibited the best anti-DENV-2 activities with an EC50 value of 0.39 ± 0.02 µM. Further experiments suggested that 6α-HEL remarkably inhibited progeny virus synthesis and mRNA and protein expression levels of E and NS1 of DENV-2. Time-of-drug-addition assay suggested that 6α-HEL inhibited intracellular replication of DENV-2 at an early stage. Moreover, 6α-HEL was shown to interact with NS5-RdRp domain at a binding affinity of -8.15 kcal/mol. SPR assay further verified 6α-HEL bound to RdRp protein with an equilibrium dissociation constant of 1.49 × 10-7 M. CONCLUSION: Ten quassinoids from E. longifolia showed anti-DENV activities at processes of virus binding and entry or intracellular replication. The most active quassinoid 6α-HEL exerts the anti-DENV-2 activities at intracellular replication stage by directly targeting the NS5-RdRp protein. These results suggest that 6α-HEL could be a promising candidate for the treatment of DENV-2 infection.

Jia-ga-song-tang protection against alcoholic liver and intestinal damage.

Gut-liver axis and cellular homeostasis play key roles in alcohol liver disease (ALD). Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a stress-sensitive guarantor of cellular homeostasis. We investigated whether the beneficial effects and underlying mechanisms of Jia-ga-song Tang (JGST) against ALD were associated with gut-liver axis and cellular homeostasis. A predictive network depicting the relationship between Jia-Ga-Song-Tang (JGST) and alcoholic liver disease (ALD) was designed by Network pharmacology. Next, 5% v/v Lieber-DeCarli alcohol liquid diet was used to establish the ALD. JGST protected the liver damage, repaired the intestines to alleviate the Two-hit on the liver, and balanced the cellular homeostasis. It was manifested in repairing the liver and intestinal pathological structure, reducing serum ALT, AST, and liver TG, TC, MDA, CAT, and increasing liver GSH, and intestine GSH-Px. JGST mainly inhibited the liver mRNA levels of HO-1, NQO1, GCLC, FASN, and PPARα and activated the intestinal mRNA levels of HO-1 and NQO1, while inhibiting the liver protein levels of HO-1, NQO1. Furthermore, LPS and LBP in the plasma and the expression of inflammatory factors such as IL-1ß, TNF-α, IL-6, TGFß1, CD14, and Myd88 were reduced after treatment to prove that JGST protects the liver from Two-hit. Ethanol was used to intervene in HepG2 and IEC-6 to establish an ALD cell model and treated by Germacrone, ML385, and TBHQ. repaired the intestinal barrier, and inhibited Nrf2 in IEC-6, but protect the HepG2 by activating Nrf2 to balance cellular homeostasis. Our results reinforce that JGST provides an effective protective method for alcoholic liver disease (ALD) by regulating Gut-liver axis and cellular homeostasis.

[Effect of titanium nitride coatings with different thickness on microhardness and cutting efficiency of nickel-titanium instruments].

PURPOSE: To investigate the effect of titanium nitride (TiN) coatings with different thicknesses on microhardness and cutting efficiency of nickel-titanium (NiTi) instruments, and to provide a basis for improving the efficiency of clinical root canal preparation. METHODS: Fifteen KV4 NiTi alloy sheets and sixty KV4 rotary NiTi files were selected and randomly divided into 5 groups: uncoated group, coating 1 h group, coating 2 h group, coating 3 h group and coating 4 h group. A layer of TiN coatings of different thicknesses was prepared on the surface of the coated groups by controlling the deposition time. The film thickness of each group was measured by scanning electron microscopy (SEM). The microhardness of each group of NiTi alloy sheets was measured by a Vickers hardness tester. Sixty transparent resin modules were selected and each resin module was prepared with one NiTi file. The cutting efficiency of each group was measured by the weight loss method. SEM was used to examine the surface of NiTi instruments in 5 groups before and after preparation. One-way variance analysis was used to determine the statistical differences with SPSS 22.0 software package. RESULTS: With the increase of the thickness of titanium nitride coating, the microhardness of NiTi alloy gradually increased(P＜0.05). With the increase of the thickness of titanium nitride coating, the cutting efficiency of NiTi instrument was improved, and the cutting efficiency was the largest when the coating thickness was 860 nm(P＜0.05). The surface morphology of the coated group was better than that of the uncoated group. CONCLUSIONS: The thickness of TiN coating affects microhardness and cutting efficiency of the nickel-titanium instruments, the microhardness and cutting ability enhanced as the thickness increased. If the thickness is too large, the cutting efficiency will be reduced.

A Rare Root Canal Configuration of a Maxillary Second Molar with Fused C-shaped Buccal Root and Five Canals: A Case Report and Review of literature.

Having a thorough knowledge of root canal configuration is essential for a successful endodontic treatment. Clinicians should always pay attention to the unusual canal configuration so as to avoid missing extra canals. This paper describes a non-surgical retreatment of a maxillary second molar with two missing root canals; diagnosed by cone-beam computed tomographic (CBCT) imaging. The tooth had three roots and five canals: a C-shaped buccal root fused by mesiobuccal (MB) and distobuccal (DB) roots with three canals (CBCT scanning showed that the second MB canal was closer to the palatal than the buccal side), a mesiopalatal root with one canal, and a distopalatal root with one canal. The purpose of this case report is to remind clinicians of the importance of anatomical variations, and thus, detection of extra canals.

[Comparison of wear resistance and flexural strength of three kinds of bulk-fill composite resins].

PURPOSE: To compare the abrasion resistance and flexure strength of three bulk-fill resin composites with an universal nano-hybrid composite resins. METHODS: The specimens were prepared with three kinds of bulk fill composites (SDR , sonicfill, Tetric N-Ceram Bulk Fill) and an universal nano-hybrid composite resins(Herculite Precis). 10 mm in diameter × 2mm in height specimens were prepared for abrasion resistance, while 2 mm in width × 2 mm in depth×25 mm in length specimens were prepared for flexure strength. The specimens were mounted in a bal1-on-disc wear testing machine and abraded with the media artificial saliva(50 N loads, 10000 cycles).Flexural test was performed with an Universal Testing Machine at a cross-head speed of 1mm/min. One-way variance analysis was used to determine the statistical differences of volume loss and flexural strength among groups with SPSS 13.0 software package(P<0.05). RESULTS: The volume loss was as follows: SDR (1.2433±0.11) mm30.05). CONCLUSIONS: With regard to wear resistance and flexural strength, Tetric N-Ceram Bulk Fill is recommended as an alternative for posterior restorations.

[Treatments of second mesiobuccal canals in maxillary permanent molar: a report of 2 cases].

With the increasing maturation of 3D printing technology, as well as its application in various industries, investigation of 3D printing technology into clinic medical education becomes an important task of the current medical education. The teaching content of oromaxillofacial head and neck surgical oncology is complicated and diverse, making lower understanding/memorizing efficiency and insufficient skill training. To overcome the disadvantage of traditional teaching method, it is necessary to introduce 3D printing technique into teaching of oromaxillofacial head and neck surgical oncology, in order to improve the teaching quality and problem solving capabilities, and finally promote cultivation of skilled and innovative talents.

[Expression of Wnt5a in chronic apical periodontitis and its clinical significance].

PURPOSE: To detect the expression of Wnt5a in lesions of chronic apical periodontitis and determine the relationship between expression of Wnt5a and inflammation degree. METHODS: Ten patients with chronic apical periodontitis and 5 healthy controls were enrolled in this study. According to the inflammatory cell infiltration, the specimens were divided into 2 groups: severe inflammation group and mild inflammation group. The expression of Wnt5a was measured by real-time PCR (RT-PCR) and immunohistochemical analysis in the lesions of chronic apical periodontitis. The amount of Wnt5 expression was assayed and compared in different inflammation levels. Statistical analysis was performed using SPSS 13.0 software package. RESULTS: Wnt5a was detected in both groups. Expression of Wnt5a mRNA in patients were significantly higher than the controls (P<0.05). According to inflammation level, the positive expression rate of Wnt5a in severe inflammation group was significantly higher than the controls (P<0.01), and Wnt5a positive expression in mild inflammation group was also significantly higher than the controls (P<0.05). The expression of Wnt5a was significantly different between severe inflammation group and mild inflammation group (P<0.05). CONCLUSIONS: The expression of Wnt5a increases as the severity of tissue inflammation increases, which indicates that Wnt5a plays an important role in the development of chronic apical periodontitis.

Biomechanical outcome of proximal femoral nail antirotation is superior to proximal femoral locking compression plate for reverse oblique intertrochanteric fractures: a biomechanical study of intertrochanteric fractures.

OBJECTIVE: Reverse obliquity intertrochanteric fractures are a challenge for orthopedic surgeons. The optimal internal fixation for repairing this type of unstable intertrochanteric fractures remains controversial. This study aimed to compare the biomechanical properties in axial load and cyclical axial load of proximal femoral nail antirotation (PFNA) and proximal femoral locking compression plate (PFLCP) for fixation of reverse obliquity intertrochanteric fractures. METHODS: Sixteen embalmed cadaver femurs were sawed to simulate reverse obliquity intertrochanteric fracture and instrumented with PFNA or PFLCP. Axial loads and axial cyclic loads were applied to the femoral head by an Instron tester. If the implant-femur constructs did not fail, axial failure load was added to the remaining implant-femur constructs. RESULTS: Mean axial stiffness for PFNA was 21.10% greater than that of PFLCP. Cyclic axial loading caused significantly less (p=0.022) mean irreversible deformation in PFNA (3.43 mm) than in PFLCP (4.34 mm). Significantly less (p=0.002) mean total deformation was detected in PFNA (6.16 mm) than in PFLCP (8.67 mm). CONCLUSION: For fixing reverse obliquity intertrochanteric fractures, PFNA is superior to PFLCP under axial load.

Evaluation of the stress distribution change at the adjacent facet joints after lumbar fusion surgery: a biomechanical study.

Spinal fusion surgery has been widely applied in clinical treatment, and the spinal fusion rate has improved markedly. However, its postoperative complications, especially adjacent segment degeneration, have increasingly attracted the attention of spinal surgeons. The most common pathological condition at adjacent segments is hypertrophic degenerative arthritis of the facet joint. To study the stress distribution changes at the adjacent facet joint after lumbar fusion with pedicle screw fixation, human cadaver lumbar spines were used in the present study, and electrical resistance strain gauges were attached on L1-L4 articular processes parallel or perpendicular to the articular surface of facet joints. Subsequently, electrical resistance strain gauge data were measured using anYJ-33 static resistance strain indicator with three types of models: the intact model, the laminectomy model, and the fusion model with pedicle screw fixation. The strain changes in the measurement sites indirectly reflect the stress changes. Significant differences in strain were observed between the normal and laminectomy state at all facet joints. Significant differences in strain were observed between the normal and the pedicle screw fixation fusion state at the L1/2 and L3/4 facet joints. The increased stress on the facet joints after lumbar fusion with pedicle screw fixation may be the cause of adjacent segment degeneration.

Biomechanical analysis of four types of internal fixation in subtrochanteric fracture models.

OBJECTIVE: To compare the biomechanical properties of four types of internal fixation (proximal femoral nail [PFN], dynamic hip screw [DHS], dynamic condylar screw [DCS], and proximal femoral locking plate [PFLP]) for different types of subtrochanteric fractures. METHODS: Thirty-two antiseptic femurs were randomly divided into four groups. After internal fixation had been implanted, different types of subtrochanteric fracture models were produced and each tested under vertical, torsional and vertical damage loads. RESULTS: The stiffness ratio of PFN in each fracture model and failure load were the highest in the four groups; however, the torsional stiffness ratio was the lowest. Tension strain ratios of DHS and DCS on the lateral side became compression strain ratios with restoration of the medial fragment. The stiffness ratio of DHS was lower than PFLP in each fracture model, torsional stiffness ratio was the highest in fracture models II to V and the failure load was lower only than PFN. The stiffness ratio and failure load of DCS were both the lowest, torsional stiffness ratio was similar to PFLP's in fracture models II to V. The stiffness ratio of PFLP was only lower than PFN's in each fracture model, but the failure load was lower than DHS's. CONCLUSION: Four types of internal fixation achieve better stabilities for type I subtrochanteric fractures. PFN and PFLP produce reliable stability in type IIIA subtrochanteric fractures. If the medial buttress is restored, DCS can be considered. For type IV subtrochanteric fractures, only PFN provides stable fixation. PFLP is suitable for comminuted fractures with large fragments.

Intramedullary nail versus dynamic compression plate fixation in treating humeral shaft fractures: grading the evidence through a meta-analysis.

There is a debate regarding the choice of operative intervention in humeral shaft fractures that require surgical intervention. The choices for operative interventions include intramedullary nailing (IMN) and dynamic compression plate (DCP). This meta-analysis was performed to compare fracture union, functional outcomes, and complication rates in patients treated with IMN or DCP for humeral shaft fractures and to develop GRADE (Grading of Recommendations, Assessment, Development, and Evaluation)-based recommendations for using the procedures to treat humeral shaft fractures. A systematic search of all the studies published through December 2012 was conducted using the Medline, Embase, Sciencedirect, OVID and Cochrane Central databases. The randomized controlled trials (RCTs) and quasi-RCTs that compared IMN with DCP in treating adult patients with humeral shaft fractures and provided data regarding the safety and clinical effects were identified. The demographic characteristics, adverse events and clinical outcomes were manually extracted from all of the selected studies. Ten studies that included a total of 448 patients met the inclusion criteria. The results of a meta-analysis indicated that both IMN and DCP can achieve similar fracture union with a similar incidence of radial nerve injury and infection. IMN was associated with an increased risk of shoulder impingement, more restriction of shoulder movement, an increased risk of intraoperative fracture comminution, a higher incidence of implant failure, and an increased risk of re-operation. The overall GRADE system evidence quality was very low, which reduces our confidence in the recommendations of this system. DCP may be superior to IMN in the treatment of humeral shaft fractures. Because of the low quality evidence currently available, high-quality RCTs are required.

[An in vitro evaluation of the effect of carboxymethyl chitosan and its composites against Enterococcus faecalis in the root canal].

PURPOSE: To evaluate the bacteriostasis effect of carboxymethyl chitosan and its composites on intracanal E. faecalis. METHODS: The pattern of E. faecalis infecting root canal was established, and then divided into 4 groups(A, B, C and D).They were filled with 2% chlorhexidine solution, 140 mg/mL mixture of carboxymethyl chitosan and chlorhexidine solution, 5 mg/mL carboxymethyl chitosan solution and calcium hydroxide paste respectively and incubated for 7 days. Samples obtained before and after the intracanal medication were plated onto BHI media to determine the colony-forming units (CFU/mL) after 48 hours. The data were analysed using SPSS 13.0 software package. RESULTS: Before intracanal medication, the variance of bacterial counts were not significantly different (P>0.05). After medication, the four groups showed significant difference in bacterial counts immediately(P<0.05).The antimicrobial effects of A and B group were better than group C and D. CONCLUSIONS: The antibiotic activity of 2% chlorhexidine solution and 140 mg/L mixture of carboxymethyl chitosan and chlorhexidine solution to E.faecalis were better. Supported by Key Science and Technology Project of Liaoning Province(2010225001).

A biomechanical study of the recovery in spinal stability of flexion/extension and torsion after the resection of different posterior lumbar structures in a sheep model.

Posterior lumbar structures are vital for spinal stability, and many researchers thought that laminectomy and facetectomy would lead to severe spinal instability. However, because living organisms have compensatory repair capacities, their long-term condition after injuries may change over time. To study the changes in the lumbar biomechanical stability of flexion/extension and torsion at different time points after the resection of various posterior structures, as well as to assess the capacity for self-healing, sheep that had undergone laminectomy or facetectomy were used as an experimental animal model. The injured sheep models included three groups: laminectomy only, laminectomy plus left total facetectomy, and laminectomy plus bilateral facetectomy. Eight nonoperative sheep were used as the control group. At 0, 6, 12, 24, and 36 weeks after injury, the lumbar specimens were harvested for biomechanical testing using the Instron 8874 servohydraulic biomechanical testing system. The changes in the injured lumbar spine were also analyzed through radiological examination. The lumbar stability in flexion/extension and torsion was severely decreased after the three types of surgery. After 6 weeks, the flexion/extension mechanical parameters recovered substantially; each parameter had returned to normal levels by 12 weeks and exceeded the intact group by 24 and 36 weeks. Torsional stiffness also recovered gradually over time. All injury groups demonstrated decreased intervertebral space and degeneration or even fusion in the small joints of the surgical segment or in adjacent segments. These results indicate that the body has the ability to repair the mechanical instability to a certain extent.

[Study of the effect of chitosan and its composites on proliferation and differentiation of mouse osteoblasts].

PURPOSE: A mouse osteoblast cell line, MC3T3-E1, was cultivated in the medium that contained chitosan, type I collagen and recombinant human bone morphogenetic protein-2 in vitro to evaluate the effect of chitosan and its composites on proliferation and differentiation of mouse osteoblasts. METHODS: This study was categorized into 4 groups based on the medium used. Group A: α-MEM medium; group B: CS, type I collagen and α-MEM medium; group C: CS, type I collagen, rhBMP-2 and α-MEM medium. α-MEM medium containing 1%FBS was used in the control group. Cells of each group were cultivated for 1,3,5 and 7 days. The optical density (OD) value at each time point was evaluated with MTT assay and growth curve was drawn to observe the proliferation of osteoblasts. Differentiation of osteoblasts was determined with alkaline phosphatase (ALP) activity assay, alkaline phosphatase staining and alizarin red staining. Alkaline phosphatase activity of each group was measured at day 1, 3, 5 and 7 days. After 7 days of culture, the cells were stained with alkaline phosphatase, and at day 14, the mineralized nodules were stained with alizarin red. Statistical analysis was performed using SPSS13.0 software package. RESULTS: The MTT assay results showed that the OD value was maximal when osteoblasts were cultured in group C. The difference were statistically significant between group C and others (P<0.05). The ALP activity showed that the result of group C was significantly higher than other groups. The increase of ALP activity was significant between group C and control group (P<0.05). However, no significant difference was found between group C and group B (P>0.05). Compared with the control group, group C had more calcium nodules and blue particles than others. CONCLUSIONS: The incorporation of type I collagen and bone morphogenetic protein-2 into chitosan can promote MC3T3-E1 cell proliferation and differentiation better. Supported by Major Science and Technology Project of Liaoning Province (2010225001).

[Effect of root canal filling with warm vertical condensation under dental operating microscope].

PURPOSE: To evaluate the clinical effect of root canal filling with warm vertical condensation with or without dental operating microscope. METHODS: Fifty maxillary anterior teeth with single, straight canals were divided into two groups. Each tooth was instrumented by X-Smart rotary nickel-titanium files to a master file 0.06 taper F3, root canal in the group 1 was obturated with warm vertical condensation using system B for downpack and Obtura II for backfilling without dental operating microscope; root canal in the group 2 was obturated using the same methods under the dental operating microscope. The effect of quality of root canal filling was evaluated by X-ray radiograph post-operatively and after two years of treatment. SPSS10.0 software package was used for Chi-square test. RESULTS: Significant difference was found between the two groups on the quality of root canal filling post-operatively (P < 0.05),with better quality of root canal filling in the group using dental operating microscope, no significant difference was found between the two groups after two years (P > 0.05). CONCLUSIONS: Warm vertical condensation under the dental operating microscope is a good method for root canal filling. It may improve the quality of root canal filling effectively, and therefore, worthy of clinical application.