How the clinical dosage of bone cement biomechanically affects adjacent vertebrae.

OBJECTIVE: This study evaluated the biomechanical changes in the adjacent vertebrae under a physiological load (500 N) when the clinically relevant amount of bone cement was injected into fractured cadaver vertebral bodies. METHODS: The embalmed cadaver thoracolumbar specimens in which each vertebral body (T12-L2) had a BMD of < 0.75 g/cm2 were used for the experiment. For establishing a fracture model, the upper one third of the L1 vertebra was performed wedge osteotomy and the superior endplate was kept complete. Stiffness of specimens was measured in different states. Strain of the adjacent vertebral body and intervertebral disc were measured in pre-fracture, post-fracture, and after augmentation by non-contact optical strain measurement system. RESULTS: The average amount of bone cement was 4.4 ml (3.8-5.0 ml). The stiffness of after augmentation was significantly higher than the stiffness of post-fracture (p < 0.05), but still lower than pre-fracture stiffness (p < 0.05). After augmentation, the adjacent upper vertebral strain showed no significant difference (p > 0.05) with pre-fracture, while the strain of adjacent lower vertebral body was significantly higher than that before fracture (p < 0.05). In flexion, T12/L1 intervertebral disc strain was significantly greater after augmentation than after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05); L1/2 vertebral strain after augmentation was significantly less than that after the fracture (p < 0.05), but there was no significant difference from that before the fracture (p > 0.05). CONCLUSIONS: PVP may therefore have partially reversed the abnormal strain state of adjacent vertebral bodies which was caused by fracture.

The mechanism of TDP-43 gene expression on inflammatory factors and the JNK and p38 MAPK signalling pathways in ischaemic hypoxic stress dependence.

In this study, the mechanism of TDP-43 gene expression on inflammatory factors and Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) signalling pathways in ischaemic hypoxic stress dependence was investigated. Sixty SD rats were selected and divided into the control group, the osteoarthritis (OA) model group, and the TDP-43-mMSCs+OA group. In the OA model group and the TDP-43-mMSCs+OA group, OA was established by collagenase injection. Western blotting assays were used to detect the expression of TDP-43 in cartilage tissues of each rat. The secretion of tumour necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in the serum of rats was determined by enzyme-linked immunosorbent assay (ELISA). The formation of cytoplasmic stress granules (SGs) and the expression of receptor for activated c-kinase 1 (RACK1) were detected by Western blotting assays in each group of rats. The expression of MTK1 and MAPKKK phosphorylation and changes in the JNK and p38 MAPK signalling pathways were detected by Western blotting assays. Compared with the control group, the expression of TDP-43 in the cartilage tissue of rats in the OA model group was significantly decreased. The expression of TDP-43 in the cartilage tissue of rats in the TDP-43-mMSCs+OA group was significantly higher than that of the control group and the OA model group, which indicates that TDP-43-mMSC transplantation was successful. Enzyme-linked immunosorbent assay results showed that the plasma TNF-α and IL-1ß levels in the OA model group were significantly increased (P < 0.01) when compared with the control group. However, the secretion of TNF-α and IL-1ß in the serum of the TDP-43-mMSCs+OA group was significantly lower than that of the model group (P < 0.01) but still higher than the control group. This indicates that overexpression of TDP-43 reduces the inflammatory response induced by OA. Western blotting assays showed that the amount of cytoplasmic SGs in the cartilage tissue of rats in the OA model group was significantly decreased when compared with the control group. The amount of SGs in the cartilage of rats in the TDP-43-mMSCs+OA group was significantly higher than that of the model group. The expression of RACK1 in the cartilage tissue of rats in the OA model group was significantly higher than that of the control group. Overexpression of the TDP-43 gene can interfere with the secretion of inflammatory factors and inhibit the activation of the JNK and p38 MAPK signalling pathways by ischaemic hypoxia stress. Thus, the molecular mechanism of chondrocytopathic lesions was reversed, which provided a new theoretical basis for the treatment of OA.

Icariin inhibits chondrocyte apoptosis and angiogenesis by regulating the TDP-43 signaling pathway.

BACKGROUND: This study focused on the mechanisms where icariin inhibited chondrocyte apoptosis and angiogenesis by regulating the TDP-43 signaling pathway. METHODS: A rat osteoarthritis (OA) model was established by collagenase injection. Histological examination of the articular cartilage and synovial tissue was performed 6 weeks after operation. Cartilage cell line overexpressing TDP-43 and mesenchymal stem cell line (TDP43-MSCs) of the rat TDP43 gene were established. RESULTS: In OA rats transplanted with TDP43-mMSCs, TDP43 was highly expressed in chondrocytes (TDP43-HC), while TDP43 expression was low in HC and MSCs-HC (p < 0.05). After the intervention of MSCs-TDP43, high expression of TDP43 induced the apoptosis and death of chondrocytes. After the addition of icariin, late apoptosis and death of TDP43-HC were significantly attenuated. Apoptosis and death of HC, MSCs-HC, and TDP43-HC cells were effectively controlled with icariin, and no apparent cell death was found. ELISA showed that the VEGF and HIF-1 alpha were significantly higher in the rat OA model than the normal control rats. CONCLUSION: TDP43-MSC transplantation interfered with the expression of TDP43 in the articular chondrocytes of OA rats, which may impact on inducing apoptosis of chondrocytes as well as inhibiting the proliferation of chondrocytes. Additionally, TDP43-MSCs appeared to promote the formation of neovascularization in the synovial tissue, which could be significantly attenuated by icariin.

DBU-Mediated Construction of 1,3,5-Trisubstituted Benzenes via Annulation of α,ß-Unsaturated Carboxylic Acids and α-Cyano-ß-methylenones.

A DBU-mediated synthesis of 1,3,5-trisubstituted benzenes was developed via the [2 + 4] annulation of in situ activated α,ß-unsaturated carboxylic acids and α-cyano-ß-methylenones. The dual role of DBU as Brønsted base and nucleophilic Lewis base is the key for the success of the reaction.

N-Heterocyclic Carbene-Catalyzed Annulation of α-Chloroaldehydes with γ-/δ-Amino-α,ß-Unsaturated Ketones: Enantioselective Synthesis of Pyrrolidones and Piperidones.

The N-heterocyclic carbene-catalyzed [2+3] and [2+4] annulations of α-chloroaldehydes with γ-/δ-amino-α,ß-unsaturated ketones were developed, giving the corresponding pyrrolidones and piperidones in good yields with exclusive trans-selectivities and excellent enantioselectivities.

Comparison of high- and low-viscosity cement in the treatment of vertebral compression fractures: A systematic review and meta-analysis.

BACKGROUND: High-viscosity cement (HVC) has been gradually applied in percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP). Although HVC has been reported to reduce cement leakage, different opinions exist. To assess the complications of HVC in cement leakage in the treatment of vertebral compression fractures and to evaluate the clinical effect of HVC compared with low-viscosity cement (LVC). METHODS: EMBASE, PubMed, Science Direct, Google Scholar and Cochrane Library databases were comprehensively searched from their inception to August 2017. Two researchers independently searched for articles and reviewed all retrieved studies. Forest plots were used to illustrate the results. The Q-test and I statistic were employed to evaluate between-study heterogeneity. Potential publication bias was assessed by funnel plot. RESULTS: HVC reduced the occurrence of cement leakage (risk ratio (RR) = 0.38, 95% confidence interval (CI) = 0.29 to 0.51, P < 0.00001), especially in the disc space (RR = 0.45, 95% CI = 0.45 to 0.80, P = 0.007) and the vein (RR = 0.54, 95% CI = 0.35 to 0.85, P = 0.008) but not in the intraspinal space (RR = 0.48, 95% CI = 0.19 to 1.23, P = 0.13) or the paravertebral area (RR = 0.63, 95% CI = 0.32 to 1.22, P = 0.17). No significant differences in the visual analogue scale (VAS), Oswestry Disability Index (ODI), injected cement volume or adjacent vertebral fracture were noted between HVC and LVC (P > 0.05). CONCLUSION: Compared with LVC, HVC results in a reduced incidence of cement leakage for the treatment of vertebral compression fractures, especially in the disc space and vein but not in the intraspinal space or the paravertebral area. In addition, HVC yields the same satisfactory clinical effect as LVC.

Ultra-early injection of low-viscosity cement in vertebroplasty procedure for treating osteoporotic vertebral compression fractures: A retrospective cohort study.

OBJECTIVE: To evaluate the clinical effect of ultra-early injection (before the phase of "tooth-paste-like") of low-viscosity cement in percutaneous vertebroplasty (PVP) for treating osteoporotic vertebral compression fractures (OVCFs). METHODS: Two hundred sixty-one patients who had PVP procedures with low-viscosity cement (ultra-early injection: 145, normal injection: 135) were included from July 2010 to July 2016 in our hospital. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Cobb angle, cement leakage, and adjacent vertebral fractures were evaluated. The follow-up period was over 12 months. RESULTS: VAS 3.0 d after surgery was significantly reduced in the ultra-early injection group compared to that in the control group (P = 0.00), but no difference was found at the final follow-up (P = 0.53). Similar results were found for ODI. The Cobb angle in both groups was recovered after PVP (P < 0.05); however, in the control group, the Cobb angle at the final follow-up was significantly increased compared with that 3.0 d after surgery (P = 0.00). There was a significant difference in the Cobb angle between the two groups at the final follow-up (P = 0.00). Regarding cement leakage, there were no significant differences in terms of mild (P = 0.58), moderate (P = 0.68), or severe leakage (P = 0.52). Seven patients in the control group had adjacent vertebral fractures, but only one patient in the ultra-early injection group experienced adjacent fractures (P = 0.03). CONCLUSIONS: Ultra-early injection of low-viscosity cement during PVP procedures in the treatment of OVCFs not only quickly and significantly relieves pain, reduces the incidence of adjacent vertebral fractures, and prevents progressive kyphotic deformity, but also does not increase the risk of cement leakage when compared with that of the traditional injection procedure.

An updated comparison of high- and low-viscosity cement vertebroplasty in the treatment of osteoporotic thoracolumbar vertebral compression fractures: A retrospective cohort study.

OBJECTIVE: This study mainly aimed to evaluate complications of cement leakage for osteoporotic thoracolumbar vertebral compression fractures by PVP using HVC, and access the clinical efficacy. METHODS: Between May 2013 and June 2015, 66 patients with osteoporotic thoracolumbar vertebral compression fractures, who underwent PVP (36 HVC and 30 LVC) in our hospital, were enrolled. Cement leakage, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), refracture of the cemented vertebrae, and adjacent vertebral fractures were evaluated. The follow-up time was 1 year. RESULTS: The overall cement leakage rate was 30.55% in the HVC group, lower than 77.77% obtained in the LVC group (P = 0.00). The incidence rates of cement leakage into paravertebral area (P = 0.02) and vein (P = 0.04) in the HVC group were significantly lower than those of the LVC group; however, no differences were found for disc space (P = 0.72) and intraspinal space (P = 0.58). There were no differences in VAS, ODI, refracture of cemented vertebrae, and adjacent vertebral fracture between the two groups (P > 0.05). CONCLUSIONS: PVP using HVC not only can reduce cement leakage, especially in the paravertebral area and peripheral vein, but also has satisfactory clinical effect.

N-heterocyclic carbene-catalyzed synthesis of spirocyclopentene-oxindoles from bromoenals.

The N-heterocyclic carbene-catalyzed tandem reaction of bromoenals and oxindoles was developed to give the corresponding chiral spirocyclopentene-oxindoles in good yields with good to high diastereo- and enantioselectivities.

Synthesis of Dihydropyridinone-Fused Indoles and α-Carbolines via N-Heterocyclic Carbene-Catalyzed [3 + 3] Annulation of Indolin-2-imines and Bromoenals.

The N-heterocyclic carbene catalyzed [3 + 3] annulation of indolin-2-imines and bromoenals was developed to give dihydropyridinone-fused indoles in good to high yields, which were transformed to α-carbolines with different 2-subsituents by a process of dehydrogenation, tosylation, and palladium catalyzed C-C or C-N coupling reaction.

Updated association of tea consumption and bone mineral density: A meta-analysis.

BACKGROUND: Current studies evaluating the association of tea consumption and bone mineral density (BMD) have yielded inconsistent findings. Therefore, we conducted a meta-analysis to assess the relationship between tea consumption and BMD. METHODS: The PubMed, Embase, and Cochrane Library databases were comprehensively searched, and a meta-analysis performed of all observational studies assessing the association of tea consumption and BMD. Forest plots were used to illustrate the results graphically. The Q-test and I statistic were employed to evaluate between-study heterogeneity. Potential publication bias was assessed by the funnel plot. RESULTS: Four cohort, 1 case-control, and 8 cross-sectional studies including a total of 12,635 cases were included. Tea consumption was shown to prevent bone loss [odds ratio (OR): 0.66; 95% confidence interval (CI), 0.47-0.94; P = 0.02], yielding higher mineral densities in several bones, including the lumbar spine [standardized mean difference (SMD): 0.19; 95% CI, 0.08-0.31; P = 0.001], hip (SMD: 0.19; 95% CI, 0.05-0.34; P = 0.01), femoral neck [mean difference (MD): 0.01; 95% CI, 0.00-0.02; P = 0.04], Ward triangle (MD: 0.02; 95% CI, 0.01-0.04; P = 0.001), and greater trochanter (MD: 0.03; 95% CI, 0.02-0.04; P < 0.00001), than the non-tea consumption group. CONCLUSION: This meta-analysis provided a potential trend that tea consumption might be beneficial for BMD, especially in the lumbar spine, hip, femoral neck, Ward triangle, and greater trochanter, which might help prevent bone loss.

[Clinical effect of staged repair and reconstruction of multiple ligament injuries in knee joints].

OBJECTIVE: To evaluate clinical outcomes of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction under arthroscopy combined with limited open repair of medial collateral ligament (MCL) for the treatment of multiple ligament injuries of knee joints. METHODS: From March 2006 and June 2012,the data of 14 patients (14 knees) with multiple injuries of ACL, PCL, and MCL were collected. There were 8 males and 6 females with an average age of (31.8 +/- 8.1) years old (ranged, 20 to 49 years old). All the patients were performed with X-ray and MRI examination, and the results showed that 10 patients had combined with injuries of anterior cruciate ligament (ACL), posterior cruciate ligament (PCL) and medial collateral ligament (MCL); 4 patients had ALC,PCL and posterolateral corner (PLC) injuries. Four patients had medial meniscus injuries and 2 patients had lateral meniscus injuries. The MCL,PLC and meniscus injuries were treated with operation on the first stage, and functional exercises were performed 3 weeks after fixation. The reconstruction operation of ACL and (or) PCL was performed at the second stage under arthroscopy 3 to 6 months later when the movement range of knee joint recovered to the normal level with obvious relaxation. RESULTS: All incisions healed by primary intention. All the patients were followed up with a mean duration of 48.9 months (ranged, 24 to 80 months). The Lysholm score was improved from preoperative 19.6 +/- 0.9 to the latest follow-up 87.1 +/- 2.8 (t=12.3, P<0.01). The International Knee Documentation Committee (IKDC) rating: 9 cases nearly recovered to normal, 5 cases were abnormal. CONCLUSION: For multiple ligament injuries in the knee, staged repair and reconstruction can effectively restore knee joint stability and function.

Expression of Fas receptor and apoptosis in vertebral endplates with degenerative disc diseases categorized as Modic type I or II.

STUDY DESIGN: Vertebral endplate tissues were obtained from patients with degenerated lumbar disc classified as Modic type 1 or type 2 and investigated with immunohistochemical staining and the DNA nick end labelling techniques. OBJECTIVE: To examine the expression of fas receptor (FasR) and apoptosis in the endplate cells isolated from patients with degenerative disc disease and to see whether they are associated with the pathological change of endplate. METHODS: Fifty-six degenerated lumbar endplate specimens were obtained from the patients with degenerative disc disease categorized as type Modic I or II in magnetic resonance imaging (MRI) and eight nondegenerated specimens as control (vertebra burst fracture patients without degenerative change in MRI) during surgical procedures. Immunohistochemical staining was performed to determine the presence of FasR and apoptosis in sections of those endplate tissues. To investigate whether the FasR expression and apoptosis in endplate were influenced by degeneration and ageing of the discs, the level of FasR expression and apoptosis in the changed and unchanged endplates was analysed. RESULTS: FasR were expressed in the cytoplasm of the endplate cells. A higher degree of FasR expression and apoptosis in endplate cells in degenerated discs was found than that in nondegenerated discs. In cell culture, the level of FasR expression and apoptosis in cells from the degenerative endplates was higher than those in unchanged endplates. The percentage of FasR-positive endplate and apoptotic endplate cells correlated significantly with the patient's age (r=0.301, p<0.05; r=0.307, p<0.05. respectively), but not with the degree of disc degeneration in MRI (r=0.047, p>0.05; r=0.066, p>0.05, respectively). CONCLUSION: This is the first study to compare the expression of FasR and apoptosis on vertebral endplate cells in degenerated disc with in nondegenerated disc. The results show that the endplate in degenerated disc may undergo fas-mediated apoptosis and vice versa, endplate degenerative changes may promotes apoptosis of the endplate cells within degenerated disc.

[Expressions of interleukin 18 and prostaglandin E2 and their correlation in the synoviocytes of patients with osteoarthritis].

OBJECTIVE: To explore the expression of interleukin 18 (IL-18) and prostaglandin E2 (PGE2) and their relationship in the synoviocytes of patients with osteoarthritis (OA). METHODS: The synovial tissues were obtained from 30 OA patients to isolate the synoviocytes for primary culture. The concentrations of IL-18 and PGE2 in the supernatants of synoviocyte culture were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The concentration of IL-18 averaged 51.559-/+27.614 pg/ml and PGE2 327.036-/+333.561 pg/ml in the supernatant of the synoviocytes. A significant positive correlation was noted between their expressions (r=0.863, P<0.01). CONCLUSION: IL-18 may induce the production of PGE2, and their interactions they may play an important role in the pathogenesis of OA.

[Biological characteristics of human degenerative vertebral endplate cells].

OBJECTIVE: To observe the morphology and phenotypes of cells extracted from the endplate in the intervertebral discs and identify the factors affecting their biological characteristic. METHODS: The intervertebral disc endplate were digested enzymatically, and the morphology of the obtained cells was examined under light microscope. Immunhistochemical analysis of collagen II and real-time PCR was carried out, and the morphologies, viability, cell growth, apoptosis and chondrocyte matrix production were compared between the cells isolated from the degenerative and normal vertebral endplates. RESULTS: The cells in primary culture presented with spherical and oval morphology, and the cytoplasm was stained blue with toluidine blue. The morphologies of the cartilage endplate cells and the articular cells were almost identical. All the freshly isolated cells expressed collagen II. The degenerative vertebral endplate cells showed decreased expression of collagen II with increased apoptotic cells as compared with normal vertebral endplate cells. CONCLUSION: The intervertebral disc endplate cells, like articular cartilage cells, express cartilage-specific matrix proteins. Degenerative vertebral endplate cells show decreased cell vitality with increases cell apoptosis.