Bispherical metal augment improved biomechanical stability in severe acetabular deficiency reconstruction: a comparative finite element analysis.

BACKGROUND: This study used finite element analysis (FEA) to compare the biomechanical stability of bispherical metal augment (BA) and wedge-shaped trabecular-metal augment (TA) in different acetabular defect reconstruction models, thereby explaining the application value of this novel bispherical augment in complex hip revision. METHODS: Three different acetabular defect pelvis models originating from three representative patients with different types of severe acetabular defects (Paprosky IIC, IIIA, and IIIB) were constructed and reconstruction with BA and TA technique was simulated. Based on the FEA models, the displacement of reconstruction implants, relative displacement of bone implants, and hemi-pelvic von Mises stress were investigated under static loads. RESULTS: BA acquired smaller reconstruction system displacement, less relative displacement of bone implants, and lower pelvic von Mises stress than TA in all Paprosky IIC, IIIA, and IIIB defect reconstructions. CONCLUSION: The FEA results show that BA could acquire favourable biomechanical stability in severe acetabular defect reconstruction. This technique is a reliable method in complex hip revision.

Modular revision strategy with bispherical augments in severe acetabular deficiency reconstruction.

PURPOSE: Reconstruction of severe acetabular deficiency is extremely challenging in total hip arthroplasty (THA) revisions. Novel bispherical augments were designed to fill acetabular bone loss and facilitate restoration of hip center of rotation (HCOR). Current study aims to compare the outcomes of bispherical augments and tantalum augments. METHODS: Between July 2017 and December 2018, bispherical augments (BA group) were implanted in 25 patients (25 hips) and 22 patients (22 hips) underwent porous tantalum augments (TA group) reconstruction in revision THA. Clinical and radiographic results were evaluated for 25 hips in BA group and 20 hips in TA group at the final follow-up. The mean duration of follow-up was 2.9 years (range, 2.2 ~ 3.7) in BA group and 2.9 years (range, 2.3 ~ 3.8) in TA group. RESULTS: Harris hip scores, HCOR, and leg length discrepancy (LLD) correction did not differ between the treatment groups. The bispherical augments were located more closer to the medial-superior part (zone II) of acetabular shell while the majority of tantalum augments were located at the lateral-superior part (zone I) (P = 0.010). More screws were used in the BA group for augment fixation (mean 2.1 vs. 1.3) (P = 0.000). There was no evidence of loosening or migration in all hips. Only one dislocation occurred in BA group and treated with closed reduction, no recurrence of instability up to the final follow-up. CONCLUSION: The clinical and radiological outcomes of bispherical augments were comparable with tantalum augments; this technique was a reliable alternative method in severe acetabular deficiency reconstruction.

Phosphate transporters, PnPht1;1 and PnPht1;2 from Panax notoginseng enhance phosphate and arsenate acquisition.

BACKGROUND: Panax notoginseng is a medicinally important Chinese herb with a long history of cultivation and clinical application. The planting area is mainly distributed in Wenshan Prefecture, where the quality and safety of P. notoginseng have been threatened by high concentration of arsenic (As) from the soil. The roles of phosphate (Pi) transporters involved in Pi acquisition and arsenate (AsV) tolerance were still unclear in this species. RESULTS: In this study, two open reading frames (ORFs) of PnPht1;1 and PnPht1;2 separated from P. notoginseng were cloned based on RNA-seq, which encoded 527 and 541 amino acids, respectively. The results of relative expression levels showed that both genes responded to the Pi deficiency or As exposure, and were highly upregulated. Heterologous expression in Saccharomyces cerevisiae MB192 revealed that PnPht1;1 and PnPht1;2 performed optimally in complementing the yeast Pi-transport defect, particularly in PnPht1;2. Cells expressing PnPht1;2 had a stronger AsV tolerance than PnPht1;1-expressing cells, and accumulated less As in cells under a high-Pi concentration. Combining with the result of plasma membrane localization, these data confirmed that transporters PnPht1;1 and PnPht1;2 were putative high-affinity H+/H2PO4- symporters, mediating the uptake of Pi and AsV. CONCLUSION: PnPht1;1 and PnPht1;2 encoded functional plasma membrane-localized transporter proteins that mediated a putative high-affinity Pi/H+ symport activity. Expression of PnPht1;1 or PnPht1;2 in mutant strains could enhance the uptake of Pi and AsV, that is probably responsible for the As accumulation in the roots of P. notoginseng.

VAMP3 and SNAP23 mediate the disturbed flow-induced endothelial microRNA secretion and smooth muscle hyperplasia.

Vascular endothelial cells (ECs) at arterial branches and curvatures experience disturbed blood flow and induce a quiescent-to-activated phenotypic transition of the adjacent smooth muscle cells (SMCs) and a subsequent smooth muscle hyperplasia. However, the mechanism underlying the flow pattern-specific initiation of EC-to-SMC signaling remains elusive. Our previous study demonstrated that endothelial microRNA-126-3p (miR-126-3p) acts as a key intercellular molecule to increase turnover of the recipient SMCs, and that its release is reduced by atheroprotective laminar shear (12 dynes/cm2) to ECs. Here we provide evidence that atherogenic oscillatory shear (0.5 ± 4 dynes/cm2), but not atheroprotective pulsatile shear (12 ± 4 dynes/cm2), increases the endothelial secretion of nonmembrane-bound miR-126-3p and other microRNAs (miRNAs) via the activation of SNAREs, vesicle-associated membrane protein 3 (VAMP3) and synaptosomal-associated protein 23 (SNAP23). Knockdown of VAMP3 and SNAP23 reduces endothelial secretion of miR-126-3p and miR-200a-3p, as well as the proliferation, migration, and suppression of contractile markers in SMCs caused by EC-coculture. Pharmacological intervention of mammalian target of rapamycin complex 1 in ECs blocks endothelial secretion and EC-to-SMC transfer of miR-126-3p through transcriptional inhibition of VAMP3 and SNAP23. Systemic inhibition of VAMP3 and SNAP23 by rapamycin or periadventitial application of the endocytosis inhibitor dynasore ameliorates the disturbed flow-induced neointimal formation, whereas intraluminal overexpression of SNAP23 aggravates it. Our findings demonstrate the flow-pattern-specificity of SNARE activation and its contribution to the miRNA-mediated EC-SMC communication.

Percutaneous endoscopic lumbar discectomy and microsurgical laminotomy : A prospective, randomized controlled trial of patients with lumbar disc herniation and lateral recess stenosis.

BACKGROUND: Sufficient decompression of the nerve root canal is still regarded as the method of choice when operating on patients with lumbar disc herniation (LDH) with lumbar lateral recess stenosis; however, tissue-sparing procedures are becoming more popular. Endoscopic techniques offer advantages and the benefits of rehabilitation, which have become the standard in many surgical operations when operating on the spine. A significant issue has been the upgrading of instruments to provide enough bone resection under continuous visual control. MATERIAL AND METHODS: We examined patients who had LDH with lateral recess stenosis and compared the results of nerve root canal decompression using percutaneous endoscopic lumbar discectomy (PELD) with a microsurgical laminotomy (ML) technique. In this study 40 patients with full endoscopic decompression or microsurgery were followed up for 2 years. In addition to general and specific parameters, the following two parameters were also used for the investigation: the Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI). RESULTS: Except for 1 patient in whom repair was done by fusion and 1 who was lost to follow-up, 38 patients remained in the study over the 2 years. The mean operating time in the PELD group was longer (p < 0.05), but intraoperative and postoperative blood loss was less than in the ML group (p < 0.05). The postoperative results were better than before surgery, and the VAS and ODI parameters indicated a clear improvement in leg pain and daily activities in both groups (p > 0.05). Of the patients three suffered increasing back pain (2 ML, 1 PELD). CONCLUSION: The results indicated that the PELD can provide an effective supplement and serve as an alternative for LDH with lateral recess stenosis compared with the ML technique when the indication criteria are fulfilled. The PELD also has the advantage of being a minimally invasive intervention.

Chondroprotective Effects of Hyaluronic Acid-Chitosan Nanoparticles Containing Plasmid DNA Encoding Cytokine Response Modifier A in a Rat Knee Osteoarthritis Model.

BACKGROUND/AIMS: Interleukin (IL)-1ß plays an essential role in the pathophysiology of osteoarthritis (OA). Cytokine response modifier A (CrmA) can prevent the generation of active IL-1ß. This study aimed to explore the chondroprotective effects of hyaluronic acid-chitosan nanoparticles containing plasmid DNA encoding CrmA (HA/CS-CrmA) in a rat OA model. METHODS: HA/CS-CrmA nanoparticles were synthesized through the complex coacervation of cationic polymers. The characteristics, toxicity, and transfection of the nanoparticles were investigated. Furthermore, the potential effects of HA/CS-CrmA nanoparticles were evaluated via a rat anterior cruciate ligament transection (ACLT) model of OA. Cartilage damage and synovial inflammation were assessed by safranin O/fast green and hematoxylin and eosin staining. Type II collagen in cartilage was measured by immunohistochemistry, and the expression levels of IL-1ß, matrix metalloproteinase (MMP)-3, and MMP-13 in synovial tissue were detected by western blot. RESULTS: The HA/CS-CrmA nanoparticles, which effectively entrapped plasmid DNA, showed an adequate size (100-300 nm) and a regular spherical shape. The nanoparticles safely transfected synoviocytes and released plasmid DNA in a sustained manner over 3 weeks. Additionally, HA/CS-CrmA nanoparticles significantly inhibited cartilage damage, synovial inflammation, and the loss of type II collagen induced by ACLT. The expression levels of IL-1ß, MMP-3, and MMP-13 in synovial tissue were dramatically down-regulated by HA/CS-CrmA nanoparticles. CONCLUSIONS: These results suggested that HA/CS-CrmA nanoparticles could attenuate cartilage destruction and protect against early OA by inhibiting synovial inflammation via inhibition of IL-1ß generation.

High-level expression of periostin is significantly correlated with tumour angiogenesis and poor prognosis in osteosarcoma.

Periostin (PN), originally named as osteoblast-specific factor-2 (OSF-2), has been involved in regulating adhesion and differentiation of osteoblasts. Recently many studies have shown that high-level expression of PN is correlated significantly with tumour angiogenesis and prognosis in many kinds of human cancer. However, whether and how periostin expression influences prognosis in osteosarcoma remains unknown. This study aimed to examine the expression of PN in patients with osteosarcoma and explore the relationship of PN expression with clinicopathologic factors, tumour angiogenesis and prognosis. Immunohistochemistry was performed to determine the expression of PN in osteosarcoma and osteochondroma respectively. Vascular endothelial growth factor (VEGF) and CD34 were also examined in tissues from the osteosarcoma patients mentioned above. The results showed that PN expression was significantly (P < 0.05) higher in osteosarcoma (80.9%) than in osteochondroma (14.7%). Increased PN protein expression was associated with histological subtype (P = 0.000), Enneking stage (P = 0.027) and tumour size (P = 0.009). The result also showed that high expression of PN correlated with VEGF expression (r = 0.285; P = 0.019) and that tumours with PN-positive expression significantly had higher microvessal density (44.6 ± 13.7 vs. 20.6 ± 6.5; P = 0.000) compared to those in normal bone tissues. Additionally, the expression of PN was found to be an independent prognostic factor in osteosarcoma patients. In conclusion, our findings suggest that PN may have an important role in tumour progression and may be used as a prognostic biomarker for patients with osteosarcoma.

Amino- and Sulfo-Bifunctionalized Metal-Organic Frameworks: One-Pot Tandem Catalysis and the Catalytic Sites.

New MIL-101 metal-organic frameworks (MOFs) dually functionalized with amino and sulfo groups were fabricated by postsynthetic modification and used to catalyze one-pot deacetalization-Knoevenagel condensation. We proved that the MOFs take the zwitterionic form, with the catalytic acid site being the ammonium group rather than the sulfo one. The acid and base concentrations in the materials are correlated, and the ratio can be readily tuned to achieve optimal catalytic performance.

Aldehyde-Tagged Zirconium Metal-Organic Frameworks: a Versatile Platform for Postsynthetic Modification.

Aldehyde-tagged UiO-67-type metal-organic frameworks (MOFs) have been synthesized via the direct solvothermal method or postsynthetic ligand exchange. Various functionalities have been introduced into the MOFs via postsynthetic modification (PSM) employing C-N and C-C coupling reactions of the aldehyde tag. Tandem PSM has also been demonstrated. An amino-functionalized MOF obtained by PSM is shown to be an efficient, heterogeneous, and recyclable catalyst for Knoevenagel condensation.

Magnetic and Photochromic Properties of a Manganese(II) Metal-Zwitterionic Coordination Polymer.

The solvothermal reaction of Mn(ClO4)2, NaN3, and a rigid viologen-tethered tetracarboxylic acid (1,1'-bis(3,5-dicarboxyphenyl)-4,4'-bipyridinium chloride, [H4L]Cl2) led to a coordination polymer of formula [Mn4(L)(N3)6(H2O)2]n. X-ray analysis revealed a 3D coordination structure. The Mn(II) ions are connected by mixed azide and carboxylate bridges to give 2D layers, which are pillared by the viologen tether of the zwitterionic ligand. Magnetic analyses suggested that the compound features antiferromagnetism and field-induced metamagnetism. The compound also shows photochromic and photomagnetic properties. The long-range magnetic ordering is owed to the spin-canting structure of the Mn(II)-azide-carboxylate layer; the photochromism involves the formation of viologen radicals via photoinduced electron transfer, and the photomagnetism is related to the interactions between the metal ion and the photogenerated radicals. The study demonstrates a strategy for the design of new multifunctional materials with photoresponsive properties.

Cementless Total Hip Arthroplasty With a High Hip Center for Hartofilakidis Type B Developmental Dysplasia of the Hip: Results of Midterm Follow-Up.

BACKGROUND: Acetabular reconstruction in adults with Hartofilakidis type B developmental dysplasia of the hip is a major technical challenge. The purpose of this retrospective study was to evaluate hip function and radiographic outcomes regarding high hip center at midterm follow-up. METHODS: From January 1, 2007 to December 31, 2009, 37 patients who had Hartofilakidis type B developmental dysplasia of the hip underwent a primary total hip arthroplasty using a high hip center technique. Functional, radiographic, and survivorship outcomes were evaluated. RESULTS: Of the 37 patients, 31 patients (83.8%) were available for the mean follow-up of 6.1 years (range, 1.5-7.6 years). Thirty-one cementless cups were located at an average vertical distance of 38.1 ± 3.3 mm and at a mean horizontal distance of 35.5 ± 3.4 mm. The mean ratio of the height of the hip center was 2.4% (range, 2.0%-2.9%). The Harris Hip Scores were improved from 50.3 points (range, 38-63 points) preoperatively to 92.3 points (range, 85-100 points) at the final follow-up (P < .001). Four patients continued to present with Trendelenburg gait pattern at the last follow-up. With use of revision for any reason and aseptic loosening as the end point, the 5-year survival rates were 90.3% (95% CI, 79.9%-100%) and 93.3% (95% CI, 84.3%-100%), respectively. CONCLUSIONS: The high hip center technique in conjunction with a cementless acetabular component seems to be a valuable alternative to achieve satisfactory midterm outcomes for Hartofilakidis type B developmental dysplasia of the hip.

Surgical treatment for young adult hip dysplasia: joint-preserving options.

Developmental dysplasia of the hip (DDH) is a spectrum of disorders that results in anatomic abnormalities leading to increased contact stress in the joint and, eventually, secondary osteoarthritis. However, many patients with DDH become symptomatic before the severe degenerative changes of the hip because of abnormal hip biomechanics, mild hip instability, impingement, or associated intra-articular pathology. Early diagnosis and appropriate treatment for DDH are of the utmost importance. With the modification of techniques like pelvic osteotomy and capsular arthroplasty, and the introduction of intracapsular procedures such as arthroscopy and femoral head-neck junction osteochondroplasty, many young patients with symptomatic hip dysplasia may benefit from joint preservation procedures. We review the current development of these concepts and the associated surgical techniques.

[The influence of sex and menstrual cycle on conditioned acquisition and extinction: Event-related potential research].

Previous studies have indicated phase-related differences in conditioned acquisition and extinction. In recent years, many researchers used event-related potential (ERP) technology to assess the extent of the acquisition and extinction. Therefore, this study was aimed to assess the sex- and menstrual cycle-dependent effects on the conditioned acquisition and extinction using ERP technology. Thirty-two females at two phases (menses phase, FM, and luteal phase, FL) of their menstrual cycle and 16 males participated in the experiment. The experiment consisted of two stages: acquisition stage and extinction stage. In the acquisition stage, in the predictable context, a condition stimulus (CS) was always followed by the presentation of a negative picture or a neutral picture; but in the unpredictable context, a CS was paired with a negative picture or a neutral picture 20% of the time. In the extinction stage, only CS was presented. The results showed that at acquisition stage, significant larger P2 amplitudes were recorded in female subjects in FL and FM in comparison with those of males. The female subjects in FL may acquire the strongest CS-US conditional connection. At extinction stage, the female subjects in FL showed larger P2 amplitudes than males, but there were no significant differences in P2 amplitudes between the males and females in FM. The results suggest that the females in FL allocate more attention resources to the acquisition of a conditioned response and delayed extinction. In conclusion, we suggest that female menstrual cycle may modulate conditioned acquisition and extinction processes, and our ERP data may provide an explanation for the premenstrual dysphoric disorder.

High expression of periostin is dramatically associated with metastatic potential and poor prognosis of patients with osteosarcoma.

BACKGROUND: Recent studies have found that periostin (PN), as a kind of secreted glycoprotein, is closely related to the metastatic potential and prognosis of many kinds of tumors. This study aimed to examine the expression of PN in patients with osteosarcoma and explore the relationship of PN expression with clinicopathologic factors and prognosis. METHODS: PN was detected by histopathological and immunohistochemical methods in 62 cases of osteosarcoma and 62 of osteochondroma. Detailed pathological and clinical data were collected by reviewing medical records. RESULTS: The results showed that increased PN protein expression was prevalent in osteosarcoma and was significantly associated with pathologic subtype (P =0.000), tumor size (P =0.016) and Enneking stage (P =0.047). Additionally, expression of PN was found to be an independent prognostic factor in osteosarcoma patients. High expression of PN protein is closely correlated to the tumor progression and poor survival of osteosarcoma. CONCLUSIONS: Our data suggest that PN is a promising biomarker for identifying individuals with poor prognostic potential and suggests its possible use as a prognostic marker in patients with osteosarcoma.

Crystal structure of aqua-chlorido-bis-(2-eth-oxy-6-formyl-phenolato-κ(2) O (1),O (6))iron(III) aceto-nitrile hemisolvate.

In the title compound, [Fe(L)2Cl(H2O)]·0.5CH3CN, (HL is 3-eth-oxy-2-hy-droxy-benzaldehyde, C9H10O3), there are two independent complex mol-ecules and one aceto-nitrile solvent mol-ecule in the asymmetric unit. In each complex mol-ecule, the Fe(III) ion has a distorted O5Cl octa-hedral coordination environment defined by two bidentate 2-eth-oxy-6-formyl-phenolato ligands, one Cl atom and one water mol-ecule. In the crystal, O-H⋯O hydrogen bonds link the two independent mol-ecules to form a dimer. The solvent mol-ecule is linked to the complex mol-ecule by a weak C-H⋯O hydrogen bond. Further weak C-H⋯O inter-actions along with weak C-H⋯Cl hydrogen bonds link the components into chains parallel to [001].

Simple, clean preparation method for cross-linked α-cyclodextrin nanoparticles via inclusion complexation.

A simple, clean method was presented in this letter to prepare cross-linked α-cyclodextrin (α-CD) nanoparticles with a low dispersion. The nanoparticles were synthesized in water by cross-linking the inclusion complex of α-CDs and poly(ethylene glycol) (PEG). The structure of the nanoparticles was characterized by (1)H NMR, nuclear overhauser enhancement spectroscopy (NOESY), and wide-angle X-ray diffraction (XRD). Spherical morphology was observed by scanning electron microscopy (SEM) for these nanoparticles. Their average hydrodynamic radius was determined to be 67 nm by dynamic light scattering (DLS). Small guest molecules could be included in the cross-linked α-CD nanoparticles, and anticancer drug cisplatin was used to evaluate the drug release behavior.

Tris[4-bromo-2-(methyl-imino-meth-yl)phenolato-κ(2) N,O]cobalt(III).

In the title compound, [Co(C8H7BrNO)3], the Co(III) ion is coordinated in a slightly distorted octa-hedral environment by three N atoms and three O atoms from three bidentate 4-bromo-2-(methyl-imino-meth-yl)phenolate ligands. The dihedral angles between the benzene rings are 82.6 (2), 57.1 (2) and 62.9 (2)°. In the crystal, mol-ecules are linked by pairs of weak C-H⋯Br hydrogen bonds, forming inversion dimers.

[Auditory event-related potentials in children with functional articulation disorders].

OBJECTIVE: To investigate the central auditory processing function in children with functional articulation disorders (FAD), and possible causes of FAD. METHODS: Twenty-seven children with FAD were selected as the case group and 50 age-matched normal children were selected as the control group. The two groups were compared with respect to the following factors: percentage of individuals with a positive history of language development disorder, and the form, peak latency and peak amplitude of mismatch negativity (MMN) on auditory event-related potentials. RESULTS: Compared with the control group, the case group had a significantly higher percentage of individuals with a positive history of language development disorder (70% vs 8%; P<0.01), a significantly prolonged peak latency of MMN (209 ± 31 ms vs 175 ± 32 ms; P<0.01), and an insignificantly lower peak amplitude of MMN (P>0.05). CONCLUSIONS: Prolonged central auditory processing may be one of the causes of FAD in children.

Mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension.

BACKGROUND: This study aimed to investigate the potential mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension (ICMT). METHODS: According to the Pfirrmann grade evaluation classification, 30 human endplate cartilage tissues were divided into the lumbar vertebra fracture (LVF) group and lumbar disc herniation (LDH) group. Then, quantitative reverse transcription polymerase chain reaction, western blot, flow cytometry, hematoxylin-eosin staining, and senescence-associated ß-galactosidase staining were performed. The difference in extracellular matrix expression between LVF and LDH endplate cartilage was detected. Second, the effect of ICMT on endplate chondrocytes degeneration was observed. Finally, the key regulatory role of YAP1 in ICMT-induced endplate cartilage degeneration was further verified. RESULTS: In degraded human endplate cartilage and tension-induced degraded endplate chondrocytes, the expression of YAP1, COL-2A, and Sox9 was decreased. Conversely, the expression of p53 and p21 was increased. By regulating YAP1 in vivo and in vitro, we can achieve alleviation of ICMT-induced senescence of endplate chondrocytes and effective treatment of disc degeneration. CONCLUSIONS: ICMT could induce senescence and degeneration of endplate chondrocytes, and ICMT-induced senescence and degeneration of endplate chondrocytes could be alleviated by regulating YAP1 expression.

Association between MTHFR C677T polymorphism and osteonecrosis of the femoral head: a meta-analysis.

The results of studies on association between the C677T polymorphism of the 5,10-methylene-tetrahydrofolate reductase (MTHFR) gene and osteonecrosis of the femoral head (ONFH) are controversial. To derive a more precise estimation of the relationship between the MTHFR C677T polymorphism and ONFH, a meta-analysis was performed. Eight studies on MTHFR C677T association with ONFH were searched up to April 2011, and the genotype frequencies in control group were consistent with Hardy-Weinberg equilibrium. The effect summary odds ratio (OR) and 95% confidence intervals were obtained. Publication bias was tested by funnel plot, Egger's regression test, and heterogeneity was assessed. Eight studies containing 778 cases and 1,162 controls were included. Heterogeneity was observed (χ(2) = 18.58, P = 0.01). Under the random effects model, the common OR was 1.38 (95% CI: 0.92-2.08; P = 0.12). In the subgroup meta-analysis, there was an association between MTHFR C677T polymorphism and ONFH in non-Asian population for CT + TT vs. CC (OR = 1.72; 95% CI: 1.21-2.43; P = 0.002; I(2) = 37.9%, P = 0.17), but not for Asian population (OR = 0.88; 95% CI: 0.66-1.66; P = 0.35; I(2) = 45.4%, P = 0.16). There was heterogeneity between studies and no clear evidence of an association on a worldwide population. When stratifying for the race, this meta-analysis did not provide an evidence of confirming association between MTHFR C677T polymorphism and ONFH. The large sample and well-designed study based on different ethnic groups should be considered in future associated studies to clarify the association of MTHFR C677T polymorphism with ONFH susceptibility.