MiR-33b-3p promotes chondrocyte proliferation and inhibits chondrocyte apoptosis and cartilage ECM degradation by targeting DNMT3A in osteoarthritis.

Osteoarthritis (OA) is a common and frequently-occurring disease in middle-aged and older people. A growing number of studies have shown that microRNAs (miRNAs) are involved in the development of OA. However, the role and mechanism of miR-33b-3p in OA remain ill-defined. The levels of miR-33b-3p and DNA methyltransferase 3A (DNMT3A) mRNA were determined by quantitative real-time polymerase chain reaction (qRT-PCR). The levels of DNMT3A protein, matrix metalloprotein 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motif-5 (ADAMTS-5), collagen II, aggrecan, cleaved Caspase-3, B-cell lymphoma-2 (Bcl-2) and BCL2-Associated X (Bax) were measured by Western blot assay. Cell proliferation and cell apoptosis were assessed by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis, respectively. The targeting relationship between miR-33b-3p and DNMT3A was verified by dual-luciferase reporter assay. The expression of miR-33b-3p was decreased and the expression of DNMT3A was increased in OA cartilage tissues and IL-1ß-induced chondrocytes. There was an inverse correlation between miR-33b-3p and DNMT3A in OA cartilage tissues. MiR-33b-3p overexpression or DNMT3A knockdown inhibited extracellular matrix (ECM) degradation and cell apoptosis and promoted cell proliferation in IL-1ß-induced chondrocytes. Moreover, DNMT3A was confirmed to be a direct target of miR-33b-3p. Upregulation of DNMT3A weakened the effects of miR-33b-3p overexpression on cartilage ECM degradation, cell proliferation and apoptosis in IL-1ß-activated chondrocytes. MiR-33b-3p overexpression suppressed cartilage ECM degradation and cell apoptosis, and promoted cell proliferation by directly targeting DNMT3A in IL-1ß-stimulated chondrocytes.

A lithium ore grade measurement based on the neutron & X-ray bi-modal imaging system.

The grades of the minerals significantly affects the energy consumption and chemical pollution along with the beneficiation process for extracting lithium element from the ores. Based on the large neutrons' macro cross section of the Li2O cluster inside the ores, the grades of lithium ores could be analyzed by the thermal neutron penetrating information. In this work, a bimodal imaging method, which utilizes both the information of penetrating neutrons and X-rays delivered by the same electron linear accelerator driven photoneutron system, was proposed to investigate the lithium concentration of each ore. A linearity R-square value of 0.991 between the results obtained with this method and those from the chemical method has been achieved. The average error in lithium concentration estimation is approximately 0.2 wt percent (wt%). The underlying principles and the experimental results will be elaborated on in this study.

The effect of femoral component valgus/varus angle on the mid-term efficacy of unicondylar knee arthroplasty.

OBJECTIVE: To investigate the effect of femoral component valgus/varus angle (FCVA) on the mid-term outcome after unicondylar knee arthroplasty. METHODS: Patients who underwent unicompartmental knee replacement in the Department of Bone and Joint Surgery, were retrospectively analyzed. According to the postoperative femoral prosthesis internal and external rotation angle, patients were divided into six groups the postoperative femoral prosthesis internal and external rotation angle: standard group, mildly abnormal group. The patients were followed up for 12 months, and complications were recorded during the follow-up period. The Range of motion (ROM), visual analog scale (VAS), and Knee society score (KSS) were compared between the six groups. RESULTS: One hundred twenty-four patients with 124 knees were included in this study. There were no statistical differences in age, gender, body mass index, preoperative ROM, or preoperative VAS, KSS-C, and KSS-F scores among the six groups. Comparison of postoperative outcomes and efficacy grades showed that: (1) the differences in ROM grades, as well as VAS, KSS-C, and KSS-F efficacy at 12 months postoperatively were statistically significant in all six groups by rank sum test; and patients in the normal group had better ROM grades and KSS-F grades than those in the mild and severe abnormality groups; (2) During the follow-up, no patient records had other serious complications such as periprosthetic infection, prosthetic loosening, periprosthetic fracture, and spacer dislocation. CONCLUSION: Controlling the femoral prosthetic internal rotation angle between 6° and 0° in unicompartmental knee replacements can lead to better mid-term outcomes for patients.

Axial Compressive Loading Attenuates Early Osteoarthritis by Reducing Subchondral Bone Remodeling.

BACKGROUND: Mechanical loading and alendronate (ALN) can be used as noninvasive physical therapy methods for osteoarthritis (OA). However, the timing and efficacy for treatments are unknown. PURPOSE: To determine whether the timing of mechanical loading and ALN influences the pathobiological changes of OA. STUDY DESIGN: Controlled laboratory study. METHODS: Mice with OA induced by anterior cruciate ligament transection were subjected to early (1-3 weeks) or late (5-7 weeks) axial compressive dynamic load or intraperitoneal injection of ALN. Changes in gait were analyzed using gait analysis system, pathobiological changes in subchondral bone, cartilage, osteophyte, and synovitis were assessed using micro-computed tomography, tartrate-resistant acid phosphatase staining, pathologic section staining, and immunohistochemistry at 1, 2, 4, and 8 weeks. RESULTS: At 1, 2, and 4 weeks, the OA limb had lower mean footprint pressure intensity, lower bone volume per tissue volume (BV/TV) in the subchondral bone, and more osteoclasts. At 4 weeks, the early loading, ALN, and load + ALN treatments induced less cartilage destruction, with a corresponding reduction in Osteoarthritis Research Society International score and increased hyaline cartilage thickness. The treatments also resulted in fewer osteoclasts and higher BV/TV and bone mineral density of subchondral bone and suppressed inflammation and interleukin 1ß- and tumor necrosis factor α-positive cells in synovium. At 8 weeks, early loading or load + ALN improved the mean footprint pressure intensity and knee flexion. At 8 weeks, early load + ALN had a synergistic effect on protecting hyaline cartilage and proteoglycans. Footprint pressure intensity and cartilage destruction were worse in late loading limbs, and no differences in BV/TV, bone mineral density, osteophyte formation, and synovium inflammation were found between the late load, ALN, and load + ALN groups and the anterior cruciate ligament transection group. CONCLUSION: Dynamic axial mechanical loading or ALN in the early stages of knee trauma protected against OA by suppressing subchondral bone remodeling. However, late loading promoted cartilage degeneration in advanced OA, indicating that reduced loading should be performed in the late stages of OA to avoid the acceleration of OA. CLINICAL RELEVANCE: Early low-level functional exercise or antiosteoporotic drugs could clearly slow or prevent the progression of early OA. For patients with mild to severe OA, loading reduction via brace protection or maintenance of joint stability via early ligament reconstruction surgery may ameliorate OA exacerbation.

An iterative prediction method for designing the moderator used for the boron neutron capture therapy.

PURPOSE: To conduct research related to slow neutrons, fast neutrons must be mode-rated and shifted to the desired energy region. METHODS: In this research, an iterated prediction method, in which the neutron transportation properties of all materials were characterized by a reflection matrix, R , and a transmission matrix, T , was proposed to bypass a time-consuming Monte Carlo simulation and predict the performance of the moderator, including the epithermal neutron flux and the dose of fast neutrons and gamma rays, used for boron neutron capture therapy (BNCT). To find the optimal solution in the huge parameter space, a genetic algorithm combined with transmission and reflection matrices was utilized. RESULTS: The results showed that a 70-loop iteration was able to find a design for the moderator of BNCT with almost 80 % higher epithermal neutron flux per kilowatt than that of the empirically optimized moderator that was previously reported in the literature. Compared with the Monte Carlo method, this method had the advantage of reducing the calculation time and statistical errors. CONCLUSION: The genetic algorithm with matrices (GAM) method can be used to find an optimal solution in a huge parameter space without brute-force calculations. It could be a promising method for designing the moderator for thermal or epithermal neutron usages.

Nano- and micro-scale zerovalent iron-activated peroxydisulfate for methyl phenyl sulfoxide probe transformation in aerobic water: Quantifying the relative roles of SO4·-, Fe(IV), and ·OH.

Multiple reactive intermediates have been proposed to be involved in peroxydisulfate (PDS) activation by zerovalent iron (ZVI), including sulfate radical (SO4·-) produced via iron-oxide shell mediated electron transfer, ferryl ion species (Fe(IV)) formed from Fe(II)-PDS interaction, and hydroxyl radical (·OH) generated by ZVI aerobic oxygenation. In this study, evolution of the relative role of these intermediates in microscale and nanoscale ZVI (mZVI vs. nZVI) activated PDS processes is comparatively investigated by using a methyl phenyl sulfoxide (PMSO) probe that selectively reacts with Fe(IV) to produce methyl phenyl sulfone (PMSO2). Interestingly, during PMSO transformation by mZVI/PDS process, yields of PMSO2 (η(PMSO2)) exhibit three-stage behavior that they first increase to a maximum (∼80% but lower than 100%) (Stage I) and then plateau for a period (Stage II) followed by a decrease phase (Stage III). Accordingly, the relative role of Fe(IV) in PMSO transformation is unceasingly improved in Stage I and subsequently reaches equilibrium with that of free radicals in Stage II, while it finally decreases in Stage III. Similar η(PMSO2) evolution trends are obtained in nZVI/PDS process, except that the η(PMSO2) increase in Stage I is negligible, possibly due to the exceptional fast nZVI dissolution. It was further clarified by tert-butyl alcohol scavenging assay that, in addition to Fe(IV), the free radical involved in Stages I and II is SO4·-, while ·OH was dominant in Stage III. Moreover, studies on O2 effect reveal that ZVI aerobic oxygenation participates in mZVI corrosion during the entire process, while it is only involved in nZVI corrosion when PDS content is reduced to a low concentration, indicating that the reactivities of PDS and O2 are similar in mZVI corrosion, but differ greatly in nZVI corrosion. Additionally, effects of reactant dose and pH on η(PMSO2) evolution are also explored. Dynamics of the relative role of different reactive oxidants should be taken into account in further applications of ZVI/PDS in situ chemical remediation technology considering their different chemistries.

Blockade of Osteoclast-Mediated Bone Resorption With a RANKL-Inhibitor Enhances Bone Formation in a Rat Spinal Fusion Model.

STUDY DESIGN: Rat spine fusion model. OBJECTIVE: The present study aimed to determine whether administration of osteoprotegerin (OPG) in a rat model of spinal fusion increases bone volume, bone density, and decreases osteoclasts in the fusion mass. SUMMARY OF BACKGROUND DATA: OPG is a soluble RANK-ligand inhibitor that blocks osteoclast differentiation and activation. This makes it a potential agent to control the remodeling process and enhance bone mass during spinal fusion. MATERIALS AND METHODS: Forty-eight male Sprague-Dawley rats received a one-level spinal fusion of L4-L5 with bone allograft. Rats were then divided into four groups according to initiation of treatment: (1) saline on day 0 (saline), (2) OPG on day 0 (OPG D0), (3) OPG on day 10 (OPG D10), and (4) OPG on day 21 (OPG D21) postsurgery. After their initial injection, rats received weekly subcutaneous injections of OPG (10 mg/kg) and were euthanized six weeks postsurgery. MicroCT analysis of the fusion site and histological analysis of bone surface for quantification of osteoclast lining was performed. RESULTS: Increased bone volume in the fusion site and around the spinous process was seen in OPG D0 and OPG D10 when compared with saline. Mean trabecular thickness was greater in all groups receiving OPG compared with saline, with OPG D0 and OPG D10 having significantly greater mean trabecular thickness than OPG D21. All OPG groups had less bone surface lined with osteoclasts when compared with Saline, with OPG D0 and OPG D10 having fewer than OPG D21. CONCLUSIONS: This study indicates that OPG inhibited osteoclast bone resorption, which led to greater bone at the fusion site. Future studies investigating OPG on its own or in combination with an osteogenic factor to improve spinal fusion outcomes are warranted to further elucidate its potential therapeutic effect.

A 3D printed mimetic composite for the treatment of growth plate injuries in a rabbit model.

Growth plate injuries affecting the pediatric population may cause unwanted bony repair tissue that leads to abnormal bone elongation. Clinical treatment involves bony bar resection and implantation of an interpositional material, but success is limited and the bony bar often reforms. No treatment attempts to regenerate the growth plate cartilage. Herein we develop a 3D printed growth plate mimetic composite as a potential regenerative medicine approach with the goal of preventing limb length discrepancies and inducing cartilage regeneration. A poly(ethylene glycol)-based resin was used with digital light processing to 3D print a mechanical support structure infilled with a soft cartilage-mimetic hydrogel containing chondrogenic cues. Our biomimetic composite has similar mechanical properties to native rabbit growth plate and induced chondrogenic differentiation of rabbit mesenchymal stromal cells in vitro. We evaluated its efficacy as a regenerative interpositional material applied after bony bar resection in a rabbit model of growth plate injury. Radiographic imaging was used to monitor limb length and tibial plateau angle, microcomputed tomography assessed bone morphology, and histology characterized the repair tissue that formed. Our 3D printed growth plate mimetic composite resulted in improved tibial lengthening compared to an untreated control, cartilage-mimetic hydrogel only condition, and a fat graft. However, in vivo the 3D printed growth plate mimetic composite did not show cartilage regeneration within the construct histologically. Nevertheless, this study demonstrates the feasibility of a 3D printed biomimetic composite to improve limb lengthening, a key functional outcome, supporting its further investigation as a treatment for growth plate injuries.

Unexpected intradural disc herniation instead of space-occupying tumor at L3-L4 level: a case report and literature review.

BACKGROUND: Lumbar disc herniation (LDH) is a common disease, with a conventional treatment method, as well as well-established surgical procedure, when necessary. However, some rare cases of LDH, such as intradural disc herniation (IDH), accounting for a very small proportion (approximately 0.3%) of all LDH cases, could lead to intra-operation or post-operation complications, which requires a more circumspect pre-operational radiology analysis and overall management. Herein, we reported a case with L3-L4 IDH identified by pathological examination. Recent studies on PubMed were reviewed to summarize the unique characteristics of IDH, as well as diagnosis and treatments. Case introduction: A 69-year-old male was admitted to our department due to complaints of chronic low back pain for the past one month, along with radiating pain along the left lower hip and posterolateral left lower extremity. Disk herniation and space-occupying mass inside the canal at the L3-L4 level were confirmed by both lumbar CT and MRI. In surgery, after resection of the disc at L3-L4, further exploration revealed unsatisfactory volume of disk tissue and local eminence posterior to ventral dura, which emphasized the need for preoperatively identifying the mass inside the spinal canal. The tumor-like mass was found inside the dura. Finally, transforaminal lumbar interbody fusion (TLIF) was performed followed by resection of the mass. However, the histology examination showed a disc-like fibrocartilage tissue. The symptoms were immensely improved after the operation. CONCLUSION: IDH has a low incidence and is sporadically reported. Misdiagnosis is very common preoperatively as well as intraoperatively. IDH usually develops more rapidly compared with intradural tumors. Adhesion between dura mater and posterior longitudinal ligament may play a critical role in the disease onset.

Anti-VEGF antibody delivered locally reduces bony bar formation following physeal injury in rats.

Physeal injuries can result in the formation of a "bony bar" which can lead to bone growth arrest and deformities in children. Vascular endothelial growth factor (VEGF) has been shown to play a role in bony bar formation, making it a potential target to inhibit bony repair tissue after physeal injury. The goal of this study was to investigate whether the local delivery of anti-VEGF antibody (α-VEGF; 7.5 µg) from alginate:chitosan hydrogels to the tibial physeal injury site in rats prevents bony bar formation. We tested the effects of quick or delayed delivery of α-VEGF using both 90:10 and 50:50 ratio alginate:chitosan hydrogels, respectively. Male and female 6-week-old Sprague-Dawley rats received a tibial physeal injury and the injured site injected with alginate-chitosan hydrogels: (1) 90:10 (Quick Release); (2) 90:10 + α-VEGF (Quick Release + α-VEGF); (3) 50:50 (Slow Release); (4) 50:50 + α-VEGF (Slow Release + α-VEGF); or (5) Untreated. At 2, 4, and 24 weeks postinjury, animals were euthanized and tibiae assessed for bony bar and vessel formation, repair tissue type, and limb lengthening. Our results indicate that Quick Release + α-VEGF reduced bony bar and vessel formation, while also increasing cartilage repair tissue. Further, the quick release of α-VEGF neither affected limb lengthening nor caused deleterious side-effects in the adjacent, uninjured physis. This α-VEGF treatment, which inhibits bony bar formation without interfering with normal bone elongation, could have positive implications for children suffering from physeal injuries.

Field study of PAHs with their derivatives emitted from e-waste dismantling processes and their comprehensive human exposure implications.

Extensive electronic waste (e-waste) recycling might be an important emission source of polycyclic aromatic hydrocarbons (PAHs) mixture, which might induce negative effects on the employees. In the present work, atmospheric pollution patterns of PAHs and their derivatives were determined in five different workshops to dismantle waste printed circuit boards (WPCBs) via thermal treatment. The results showed that mass concentrations of PAHs, chlorinated PAHs (ClPAHs), brominated PAHs (BrPAHs), oxy-PAHs (OPAHs) as well as carbazole (CBZ) were ranged from 1.53 × 104-2.02 × 105, 32.3-364, 8.29-1.13 × 103, 923-1.39 × 104 and 225-1.95 × 103 pg·m-3, respectively. Electric heating furnaces (EHF) workshops emitted relatively higher contaminants than other disposal sectors. OPAHs was found to be the most predominant derivatives of PAHs with 9,10-anthraquinone (83.0%) has the absolute superior in EHFTV, while benzo(a)anthracene-7,12-dione (>45.0%) was found to be the highest congener in other workshops, respectively. 9,10-Cl2Phe exhibited the largest contributions to the ΣClPAHs whereas the composition profiles of BrPAHs varied among five workshops. In addition to direct chlorination of parent PAHs, thermal degradation of halogenated flame retardants incorporated into plastic materials might dominate the generation of Cl/BrPAHs from e-waste dismantling activities. The specific isomeric ratios of BrPAHs (3-BrFlu/1-BrPyr and 1-BrPyr/3-BrFlu) might be used to discriminate other emission sources from pyrolysis of WPCBs. However, their specific application as novel tracers for source identification should be further verified with more studies. The emitted PAHs mixture with their derivatives in all dismantling workshops posed carcinogenic risks to these dismantling workers via inhalation, particularly the workshop using electric heating furnaces to treat router. Nevertheless, new loadings of PAHs derivatives observed from e-waste dismantling activities, as well as their comprehensive health risk assessment provides us with a fresh perspective on the source appointment and potential adverse consequences of PAHs. More attention needs to be paid to the potential carcinogenic risks of exposure to PAHs and their derivatives from e-waste dismantling processes.

In vivo degradation rate of alginate-chitosan hydrogels influences tissue repair following physeal injury.

The physis is a cartilaginous tissue in children's long bones that is responsible for bone elongation. Physeal injuries can heal with bony repair tissue known as a "bony bar," and this can cause growth deformities. Current treatments involve surgical resection of the bony bar and insertion of inert materials in hopes of preventing bony bar re-formation and preserving bone elongation. However, these materials frequently fail and the bony bar commonly returns. This study investigated alginate-chitosan hydrogels as interpositional materials to block bony bar formation in a rat model of physeal injury. Further, biomaterial properties such as substrate stiffness, permeability, and degradation rate were studied. Different ratio alginate:chitosan hydrogels with or without calcium cross-linking were tested for their inhibition of bony bar formation and restoration of the injured physis. Alginate:chitosan were mixed (a) 90:10 with calcium (90:10 + Ca); (b) 50:50 with calcium (50:50 + Ca); (c) 50:50 without calcium (50:50 - Ca); and (d) 50:50 made with irradiated alginate (IA) and without calcium. We found that repair tissue was determined primarily by the in vivo degradation rate of alginate-chitosan hydrogels. 90:10 + Ca had a slow degradation rate, prevented cellular infiltration, and produced the most bony bar tissue while having softer, more permeable material properties. IA had the fastest degradation, showed high cellular infiltration, and produced the most cartilage-like tissue while having stiffer, less permeable material properties. Our results suggest that the in vivo biomaterial degradation rate is a dynamic property that can be optimized to influence cell fate and tissue repair in physeal injuries.

Rabbit Model of Physeal Injury for the Evaluation of Regenerative Medicine Approaches.

Physeal injuries can lead to bony repair tissue formation, known as a bony bar. This can result in growth arrest or angular deformity, which is devastating for children who have not yet reached their full height. Current clinical treatment involves resecting the bony bar and replacing it with a fat graft to prevent further bone formation and growth disturbance, but these treatments frequently fail to do so and require additional interventions. Novel treatments that could prevent bone formation but also regenerate the injured physeal cartilage and restore normal bone elongation are warranted. To test the efficacy of these treatments, animal models that emulate human physeal injury are necessary. The rabbit model of physeal injury quickly establishes a bony bar, which can then be resected to test new treatments. Although numerous rabbit models have been reported, they vary in terms of size and location of the injury, tools used to create the injury, and methods to assess the repair tissue, making comparisons between studies difficult. The study presented here provides a detailed method to create a rabbit model of proximal tibia physeal injury using a two-stage procedure. The first procedure involves unilateral removal of 25% of the physis in a 6-week-old New Zealand white rabbit. This consistently leads to a bony bar, significant limb length discrepancy, and angular deformity within 3 weeks. The second surgical procedure involves bony bar resection and treatment. In this study, we tested the implantation of a fat graft and a photopolymerizable hydrogel as a proof of concept that injectable materials could be delivered into this type of injury. At 8 weeks post-treatment, we measured limb length, tibial angle, and performed imaging and histology of the repair tissue. By providing a detailed, easy to reproduce methodology to perform the physeal injury and test novel treatments after bony bar resection, comparisons between studies can be made and facilitate translation of promising therapies toward clinical use. Impact Statement This study provides details to create a rabbit model of physeal injury that can facilitate comparisons between studies and test novel regenerative medicine approaches. Furthermore, this model mimics the human, clinical situation that requires a bony bar resection followed by treatment. In addition, identification of a suitable treatment can be seen in the correction of the growth deformity, allowing this model to facilitate the development of novel physeal cartilage regenerative medicine approaches.