Early predictors of delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae in children: a retrospective study in China.

BACKGROUND: Lobar pneumonia caused by Mycoplasma pneumoniae is a relatively difficult-to-treat pneumonia in children. The time of radiographic resolution after treatment is variable, a long recovery time can result in several negative effects, and it has attracted our attention. Therefore, exploring factors associated with delayed radiographic resolution will help to identify these children at an early stage and prepare for early intervention. METHODS: The data of 339 children with lobar pneumonia caused by Mycoplasma pneumoniae were collected from the Department of Pediatrics of Fu Yang People's Hospital, China from January 2021 to June 2022. After discharge, the children were regularly followed up in the outpatient department and on the WeChat platform for > 8 weeks. According to whether pulmonary imaging (chest radiography or plain chest computed tomography) returned to normal within 8 weeks, the children were divided into the delayed recovery group (DRG) (n = 69) and the normal recovery group (NRG) (n = 270). The children's general information, laboratory examination findings, bronchoscopy results, and imaging findings were retrospectively analyzed. Single-factor analysis was performed to identify the risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae, and the factors with statistically significant differences underwent multiple-factor logistic regression analysis. Receiver operating characteristic (ROC) analysis was then performed to calculate the cutoff value of early predictive indicators of delayed radiographic resolution. RESULTS: Single-factor analysis showed that the following were significantly greater in the DRG than NRG: total fever duration, the hospitalization time, C-reactive protein (CRP) level, lactate dehydrogenase (LDH) level, D-dimer level, pulmonary lesions involving two or more lobes, a large amount of pleural effusion, the time to interventional bronchoscopy, and mucus plugs formation. Multivariate logistic regression analysis showed that the hospitalization time, CRP level, LDH level, pulmonary lesions involving two or more lobes, and a large amount of pleural effusion were independent risk factors for delayed radiographic resolution of lobar pneumonia caused by Mycoplasma pneumoniae. The cutoff values on the receiver operating characteristic curve were a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92 mg/L, and LDH level of ≥ 378 U/L. CONCLUSION: If patients with lobar pneumonia caused by Mycoplasma pneumoniae have a hospitalization time of ≥ 10.5 days, CRP level of ≥ 25.92 mg/L, and LDH level ≥ 378 U/L, the time of radiographic resolution is highly likely to exceed 8 weeks. Pediatricians must maintain a high level of vigilance for these factors, control the infection as early as possible, strengthen airway management, and follow up closely to avoid complications and sequelae of Mycoplasma pneumoniae pneumonia.

A cell adhesion-promoting multi-network 3D printing bio-ink based on natural polysaccharide hydrogel.

Due to its high biosafety, gellan gum (GG) hydrogel, a naturally occurring polysaccharide released by microorganisms, is frequently utilized in food and pharmaceuticals. In recent years, like GG, natural polysaccharide-based hydrogels have become increasingly popular in 3D-printed biomedical engineering because of their simplicity of processing, considerable shear thinning characteristic, and minimal pH dependence. To mitigate the negative effects of the GG's high biological inertia, poor cell adhesion, single cross-linked network, and high brittleness. Mesoporous silica nanospheres (MMSN) and Aldehyde-based methacrylated hyaluronic acid (AHAMA) were combined to sulfhydrated GG (TGG) to create a multi-network AHAMA/TGG/MMSN hydrogel in this study. For this composite hydrogel system, the multi-component offers several crosslinking networks: the double bond in AHAMA can be photocrosslinked by activating the photoinitiator, aldehyde groups on its side chain can create Schiff base bonds with MMSN, while TGG can self-curing at room temperature. The AHAMA/TGG/MMSN hydrogel, with a mass ratio of 2:6:1, exhibits good cell adhesion, high strength and elasticity, and great printability. We believe that this innovative multi-network hydrogel has potential uses in tissue regeneration and biomedical engineering.

miRNA-382-5p Carried by Extracellular Vesicles in Osteoarthritis Reduces Cell Viability and Proliferation, and Promotes Cell Apoptosis by Targeting PTEN.

The objective of the study was to identify extracellular vesicle (EV) microRNAs (miRNAs) that play important roles in knee osteoarthritis (OA). Models of knee OA were surgically induced in nine male Sprague-Dawley rats. Tissue samples were collected at 0 weeks (Control), 6 weeks (6 weeks), and 12 weeks (12 weeks). The EVs were isolated and analyzed for size. Various biomarkers, including recombinant tetraspanin 30 cluster of differentiation (CD)63 and CD9 were detected. An Agilent array was used to screen for differentially expressed (DE) miRNAs. The levels of DE miRNAs and their target mRNAs were evaluated by quantitative reverse transcription-polymerase chain reaction and western blotting. The viability, proliferation, and apoptosis of lipopolysaccharide (LPS)-induced human synovial cells (HSCs) were examined by using Cell Counting Kit-8, EdU (5-ethynyl-2'-deoxyuridine), and TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) assays, respectively. The OA model rats had significantly increased levels of inflammatory activity, damaged cells, and rough articular cartilage when compared with rats in the control group. The EVs from the model rats appeared as round vesicle-like structures with a mean diameter of ∼145 nm. Five miRNAs that showed gradual increases in the model rats were selected for further analysis; those miRNAs included miR-127-3p, miR-132-3p, miR-141-3p, miR-345-5p, and miR-382-5p. miR-382-5p was found to reduce the viability and proliferation and promote the apoptosis of LPS-induced HSCs. Moreover, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was negatively regulated by miR-382-5p. Our findings revealed that EVs produced by the OA rats contained miR-382-5p, which might reduce cell viability and proliferation, and promote cell apoptosis by targeting PTEN.

Transverse Tibial Bone Transport Enhances Distraction Osteogenesis and Vascularization in the Treatment of Diabetic Foot.

OBJECTIVE: To investigate the effect of transverse tibial bone transport on the treatment of Wagner Stage 4 diabetic foot. METHODS: From January 2017 to October 2019, a total of 19 patients with Wagner Stage 4 diabetic foot ulcers were recruited. All patients were treated with transverse tibial bone transport. A detailed follow-up was carried out at 1 week, 1 month, 3 months, 6 months, and 1 year after surgery. The wound healing rate and the limb salvage rate at 1 year after the surgery were evaluated. Preoperative and 3-month postoperative digital subtraction angiography (DSA) were obtained. The level of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF) and platelet-derived growth factor (PDGF) before surgery and on 1st, 4th, 11th, 18th, 28th , and 35th days after surgery were measured. Operation time, intraoperative blood loss, postoperative complications, visual analog scale (VAS) pain score, skin temperature, Semmes-weinstein monofilament (SWM), and ankle brachial index (ABI) were also assessed. RESULTS: The wound healing rate and the limb salvage rate were both 94.74% in the patients at 1 year after the surgery. DSA showed the thickening of the calf and foot arteries, clear visualization, and a rich vascular network. The levels of VEGF, bFGF, and PDGF on the 11th, 18th, 28th , and 35th days after surgery were significantly higher than those before surgery (p < 0.05). The EGF level on the 18th, 28th, and 35th days after surgery was significantly higher than that before surgery (p < 0.05). Superficial wound complications occurred in one patient during the hospitalization. There was no movement area infection, skin flap necrosis, tibial fracture, loosening of the external fixator, or rupture in study. CONCLUSION: Transverse tibial bone transport can improve the blood circulation of the affected limbs, promote the healing of diabetic foot wounds, and reduce the amputation rate of the affected limbs. Transverse tibial bone transport can promote the healing of Wagner Stage 4 diabetic foot.

The silencing of miR-199a-5p protects the articular cartilage through MAPK4 in osteoarthritis.

Background: Osteoarthritis (OA) is the most common joint disorder, and places a heavy burden on individuals and society. As conventional therapies, such as surgery, rarely cure the disorder, targeted therapies represent a promising alternative. This research sought to explore the potential effect of miR-199a-5p on the development of OA. Methods: Based on the OA rat model, the serum was collected at 6 and 12 weeks, and microRNA (miRNA) sequencing was performed. A bioinformatics analysis was conducted to examine the differentially expressed micro ribonucleic acids, and qRT-PCR (real-time quantitative PCR) was conducted to determine their expression in the joint tissues of rats with OA. Rats articular chondrocytes were collected and treated with a miR-199a-5p antagomir or agomir. Afterwards, cell viability, autophagy was determinated. Dual luciferase was used to verify that miR-199a-5p targets the regulation of mitogen-stimulated protein kinase 4 (MAPK4). Subsequently, in chondrocytes, MAPK was knockdown to rescue the effect of miR-199a-5p inhibition, and cell viability and autophagy were examined. Finally, the OA model was treated with miR-199a-5p antagomir to detect joint pathology, cartilage tissue and inflammatory factor and autophagy was measured. Results: MiR-199a-5p was greatly upregulated in OA, and miRNA was found to be differentially expressed in OA tissues. MAPK4 was identified to be a target gene of miR-199-5p. Inhibiting miR-199a-5p not only decreased the survival of chondrocytes and induced apoptosis, but also relieved inflammation and decreased the content of pro-inflammatory cytokines. Further, the silencing of miR-199a-5p protected the articular cartilage and improved gait abnormalities, but this effect was abrogated by the silencing of MAPK4. Conclusions: The silencing of miR-199a-5p appears to improve gait abnormalities, promote the survival of chondrocytes, and improve the condition of OA. Our findings may lead to the development of miR-199a-5p-based targeted therapy for OA.

A Vaginitis Classification Method Based on Multi-Spectral Image Feature Fusion.

Vaginitis is one of the commonly encountered diseases of female reproductive tract infections. The clinical diagnosis mainly relies on manual observation under a microscope. There has been some investigation on the classification of vaginitis diseases based on computer-aided diagnosis to reduce the workload of clinical laboratory staff. However, the studies only using RGB images limit the development of vaginitis diagnosis. Through multi-spectral technology, we propose a vaginitis classification algorithm based on multi-spectral image feature layer fusion. Compared with the traditional RGB image, our approach improves the classification accuracy by 11.39%, precision by 15.82%, and recall by 27.25%. Meanwhile, we prove that the level of influence of each spectrum on the disease is distinctive, and the subdivided spectral image is more conducive to the image analysis of vaginitis disease.

Quercetin Alleviates Osteoarthritis Progression in Rats by Suppressing Inflammation and Apoptosis via Inhibition of IRAK1/NLRP3 Signaling.

INTRODUCTION: Quercetin was recently reported to help protect against osteoarthritis (OA) progression, but the molecular mechanism for that protective affect remains unclear. METHODS: Here, OA model rats were intraperitoneally injected with quercetin, and the severity of cartilage damage in the rats was evaluated by H&E, Safranin O, and Toluidine blue, as well as by using the Osteoarthritis Research Society International (OARSI) Scoring System. Additionally, rat chondrocytes were treated with quercetin and then stimulated with IL-1ß. The levels of pro-inflammatory cytokines (IL-1ß, IL-18, and TNF-α) were detected by ELISA.Cell apoptosis was evaluated by flow cytometry and Hoechst staining. ROS levels were measured using a DCFH-DA probe. Protein expression was evaluated by Western blotting, immunohistochemical staining, and immunofluorescence. RESULTS: Our data showed that quercetin attenuated the degeneration and erosion of articular cartilage, suppressed inflammation and apoptosis, and downregulated the levels of IRAK1, NLRP3, and caspase-3 expression. In vitro data showed that overexpression of NLRP3 could reverse the suppressive effect of quercetin on IL-1ß-induced rat chondrocyte injuries. Importantly, rescue experiments confirmed that quercetin inhibited IL-1ß-induced rat chondrocyte injuries in vitro by suppressing the IRAK1/NLRP3 signaling pathway. CONCLUSION: Our study indicated that quercetin inhibits IL-1ß-induced inflammation and cartilage degradation by suppressing the IRAK1/NLRP3 signaling pathway.

Role of tribochemistry reactions of B4C on tribofilm growth at a PEEK-steel interface in simulated body fluids.

Corrosion and wear products of metallic implants can lead to severe adverse tissue reactions. However, there is an absence of effective means to reduce the tribocorrosion of metal. The main purpose of this study is to reveal a mechanism of engineering a barrier layer on metal surfaces via adding functional particles into the polymer counterpart. B4C and BN particles were compounded into a polyetheretherketone (PEEK) matrix and their tribological performance of PEEK-based composites sliding against stainless steel was compared in simulated body fluid. Results demonstrate that the addition of B4C reduces significantly friction and wear. In particular, the addition of only 1 vol% B4C reduces wear of PEEK by up to 94.8%, and tribocorrosion of steel is also obviously mitigated. It is discovered that hydrolysis of B4C particles triggered by friction and deposition of Ca2+ and phosphate ions dominate formation of the barrier layer at the friction interface. The barrier layer endows the PEEK-metal sliding pair simultaneously enhanced anti-wear and anti-corrosion performance.

Clinical Characteristics and the Risk Factors of Hepatic Injury in 221 Children With Infectious Mononucleosis.

Background: Infectious mononucleosis caused by Epstein-Barr Virus infection is a common acute infectious disease in children. About 40-80% of children with infectious mononucleosis have hepatic injury, and hepatic failure is one of the main causes of death in patients with fatal infectious mononucleosis. Identifying the demographics, presenting clinical characteristics and the risk factors of hepatic injury in infectious mononucleosis children are helpful to remind clinicians which patients are prone to have hepatic damage. Methods: A descriptive, cross-sectional study with a 31-month retrospective review was performed on all infectious mononucleosis children hospitalized in the pediatric department of Fuyang People's Hospital. Demographic data, presenting features, radiology imaging, clinical and laboratory parameters, and clinical outcomes of infectious mononucleosis children were collected. Results: Two-hundred twenty-one infectious mononucleosis inpatients were enrolled, and 43.9% (97/221) patients were considered to have a hepatic injury (defined as alanine amino transaminase > 40 U/L). Compared with patients without hepatic injury, hepatic injury patients were marked with a significantly higher percentage of hepatomegaly (31 vs. 49%), splenomegaly (58 vs. 81%) and palpebral edema (47 vs. 63%), higher age (3.05 ± 2.12 vs. 3.84 ± 2.44), hospitalization days (6.85 ± 2.64 vs. 8.08 ± 2.83), leukocyte (14.24 ± 5.32 vs. 18.53 ± 8.63), lymphocytes (9.48 ± 4.49 vs. 13.80 ± 7.47), the proportion of atypical lymphocytes (0.12 ± 0.07 vs. 0.15 ± 0.08) and aspartate aminotransferase (33.71 ± 10.94 vs. 107.82 ± 93.52). The results of correlation analysis and multiple linear regression analysis indicated that age (OR = 1.185; 95% CI = 1.035-1.357, p = 0.014), female (OR = 2.002, 95% CI: 0.261-0.955, p = 0.036) and splenomegaly (OR = 2.171, 95% CI: 1.018-4.628, p = 0.045) were independent risk factors of hepatic injury. Conclusions: In this study, the hepatic injury was associated with gender, age, and splenomegaly, which improved our understanding of risk factors about hepatic injury among infectious mononucleosis children.

[Effect of transverse tibial bone transport on expression of serum angiogenesis-related growth factors].

OBJECTIVE: To investigate the effect of transverse tibial bone transport on the expression of angiogenesis-related growth factors in the serum of diabetic foot patients. METHODS: Between January 2018 and December 2018, 10 patients who suffered from diabetes mellitus accompanied with Wagner stage 4 diabetic foot underwent transverse tibial bone transport. There were 5 males and 5 females with an average age of 59.2 years (range, 51-70 years). The duration of diabetes was 2-60 months, with an average of 24.2 months. The duration of diabetic foot was 30-120 days, with an average of 54.1 days. Peripheral venous blood was taken at 1 day before operation and at 1, 4, 11, 18, 28, and 35 days after operation. The serum was centrifuged and subjected to ELISA test to detect the expression levels of serum vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF). RESULTS: The levels of serum VEGF, bFGF, and EGF increased rapidly at 11 days after operation, and the expression levels of the factors at 11, 18, 28, and 35 days were significantly higher than those before operation ( P<0.05). The expression level of PDGF increased suddenly at 18 days after operation, and the expression level of PDGF at 18, 28, and 35 days was significantly higher than that before operation ( P<0.05). CONCLUSION: Transverse tibial bone transport for the treatment of diabetic foot can significantly increase the expression of serum angiogenesis-related growth factors in early stage, which may be the mechanism of promoting the healing of diabetic foot wounds.

Tuning the tribofilm nanostructures of polymer-on-metal joint replacements for simultaneously enhancing anti-wear performance and corrosion resistance.

Total joint replacement is currently the most successful clinical treatment for improving the life quality of individuals afflicted with end-stage osteoarthritis of knee or hip joints. However, release of wear and corrosion products from the prostheses is a critical issue causing adverse physiological responses of local issues. ß-SiC nanoparticles were dispersed into polyetheretherketone (PEEK) materials and their role in tribocorrosion performance of PEEK-steel joints exposed to simulated body fluid was investigated. It is demonstrated that ß-SiC nanoparticles increase greatly the wear resistance of the PEEK materials, and meanwhile mitigate significantly corrosion of the steel counterpart. It is revealed that tribochemical reactions of ß-SiC nanoparticles promoted formation of a robust tribofilm having complex structures providing protection and shielding effects. The present work proposes a strategy for developing high-performance polymer-on-metal joint replacement materials of enhanced lifespan and biocompatibility via tuning interface nanostructures. STATEMENT OF SIGNIFICANCE: Adverse tissue responses to metal wear and corrosion products from metal base implants remain a challenge to surgeons and patients. We demonstrated that leaching of metal ions and release of metallic debris are well decreased via tuning interface nanostructures of metal-polymer joint bearings by dispersing ß-SiC nanoparticles into polyetheretherketone (PEEK). It is identified that the addition of ß-SiC greatly improves the tribological performances of the PEEK materials and mitigated corrosion of the steel. Tribo-chemistry reactions of SiC induce the formation of complex structures which provide protection and shielding effects. Nanostructures of the tribofilm were also comprehensively investigated. These novel findings proposed a potential route for designing high performance metal-polymer joint replacement materials.

Early Out-of-Bed Functional Exercise Benefits Elderly Patients Following Hip Fracture: A Retrospective Cohort Study.

Hip fracture is a worldwide medical problem with devastating consequences. Older adults are at higher risk for complications and have more mobility limitation. The aim of this study was to assess the impact of delay in out-of-bed functional exercise on one-year mortality and functional outcomes for elderly patients with hip fracture in China. 1,022 cases of patients with hip fracture who were older than 75 were involved in this retrospective cohort study between 2007 and 2017. One-year mortality, follow up Activities of Daily Living (ADL) score, and Harris hip score were collected. Patients with hip fracture experienced an average of 2.9 days of in-bed functional exercise, 41.4% (n = 423) taken out-of-bed functional exercise within 2 days. A Cox proportional regression model showed that after adjustment for age, sex, cardiovascular disease, and urinary disease, delayed out-of-bed functional exercise (> 2 days) associated with higher one-year mortality (OR = 1.38, 95% confidence interval [CI]: 1.09 to 1.69). Ordinary least squares regression showed that delayed out-of-bed functional exercise associated with worsen ADL scores at 1-month (difference of -3.9 points, 95% CI: -6.4 to -1.7), although the long term ADL scores did not have increased. In addition, there were no associations between out-of-bed functional exercise timing and the Harris hip score at 12 months. In conclusion, in elderly patients with hip fracture in China, delayed out-of-bed functional exercise was not associated with improved Harris hip score, but it was associated with worsen ADL capacities at 1-month postoperatively and higher one-year mortality. The present study emphasizes the benefit of early out-of-bed exercise on the majority of elderly patients with hip fracture.

Switching Brake Materials To Extremely Wear-Resistant Self-Lubrication Materials via Tuning Interface Nanostructures.

Tribological performance of motion components is one of the key aspects that must be considered in a wide range of applications such as vehicles, aircrafts, and manufacturing equipment. This work demonstrates that further addition of only low-loading hard nanoparticles into a formulated nonasbestos organic brake material directly switches its functionality to a self-lubrication material. More importantly, the newly developed nanocomposites exhibit an extremely low wear rate. Comprehensive investigations on the friction interface reveal that the great friction and wear reduction are due to the formation of a nanostructured lubricious tribofilm. Tribofilm formation is continuously fed by complex molecular species released from the bulk nanocomposites, for which nanoparticles digested within the tribofilm greatly enhance its robustness and lubricity. This work gains insight into the crucial role of the interface nanostructure and paves a route for developing extremely wear-resistant self-lubrication composites for numerous applications.

Significance of an in-situ generated boundary film on tribocorrosion behavior of polymer-metal sliding pair.

Polymer composites have a high potential for applications as tribo-materials exposed to sea water owing to their self-lubrication characteristic and high chemical stability. In the present work, tribological behaviors of polyetheretherketone (PEEK) composites rubbing with stainless steel in sea water were explored using a pin-on-disc tribometer integrated with a potentiostat for electrochemical control. It was demonstrated that further adding 5 vol% hexagonal boron nitride (h-BN) nanoparticles into PEEK reinforced with short carbon fibers (SCF) significantly enhanced the wear resistance. Moreover, the stainless steel exhibited significantly enhanced tribocorrosion resistance when rubbing with the hybrid nanocomposite, in comparison to the sliding against PEEK filled only with SCF. Nanostructures of the boundary films formed on the steel surface were comprehensively investigated. It was manifested that tribo-chemistry products of h-BN, i.e. H3BO3 and B2O3, were arrayed in a closely packed boundary film. It seems that inclusion of layer-structured H3BO3 and B2O3 improved the resilience of the boundary film. The continuous boundary film covering the steel surface provided a lubrication effect and strengthened the passivation layer. A new route for enhancing simultaneously tribological and corrosion resistance of polymer-metal pairs by controlling in-situ tribo-chemistry was thus proposed.

MiR-132-3p regulates ADAMTS-5 expression and promotes chondrogenic differentiation of rat mesenchymal stem cells.

Previous study showed that miRNA aberrant expression is involved in chondrogenic differentiation. In this study, we aimed to investigate the effects of miR-132-3p on chondrogenic differentiation and the underlying mechanisms. First, quantitative PCR were performed to determine the level of MiR-132-3p. Then, we used luciferase assay to examine the target of miR-132-3p. Proteoglycan was tested by Alcian blue staining assay. Moreover, the sex determining region Y-box 9 (SOX9), Collagen type II alpha 1 chain (COL2A1) and Aggrecan (ACAN) levels were analyzed by quantitative PCR, immunofluorescence and Western blotting. Our results showed that MiR-132-3p level was reduced in rat MSCs (rMSCs) during chondrogenic differentiation. Ectopic expression of miR-132-3p induced proteoglycan accumulation and the increase of ACAN, SOX9 and COL2A1 expression, which were involved in inducing chondrogenic differentiation of rMSCs. More importantly, ADAMTS-5 was identified as the target of MiR-132-3p. Knockdown of ADAMTS-5 increased proteoglycan level, but reduced the SOX9, ACAN, and COL2A1 levels during chondrogenic differentiation of rMSCs. Taken together, our results revels that MiR-132-3p promotes rMSCs chondrogenic differentiation, possibly mediated by targeting ADAMTS-5, which provided new perspective on the chondrogenic differentiation and pathology of osteoarthritis.

Quercetin reduces neural tissue damage and promotes astrocyte activation after spinal cord injury in rats.

Spinal cord injury (SCI) is lead to locomotor impairment because of neurological damage after following trauma. Quercetin (Que) has been confirmed to have a neuro-protective effect during nerve damage processes. The purpose of this study was to determine the roles of Que in functional recovery, cavity formation, astrocyte activation, and nerve regeneration following SCI. Sprague-Dawley rats were randomly divided into three groups: Sham group, SCI group, and Que + SCI group. A rat model of SCI was made at T10 using the modified Allen's method. In the Que + SCI group, animals underwent laminectomy and were then intraperitoneally injected with 20 mg/kg Que for 7 days. Locomotor function was determined with the Basso, Beattie, Bresnahan (BBB) scores at 1, 3, 5, and 7 days post-injury. At 7 days post-injury, somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) were recorded. Hematoxylin-Eosin (HE) staining was used to investigate cavity formation. Astrocyte activation was assayed by immunohistochemistry staining with an antibody specific for glial fibrillary acidic protein (GFAP), as well as the expression of GFAP and S100ß. Axons were stained using an antibody specific for neurofilament 200 (NF200) and 5-hydroxytryptamine (5-HT). In addition, the protein level of BDNF, p-JNK2, and p-STAT3 was detected using Western blot. Que promoted locomotor function and electrophysiological recovery, reduced cavity formation, contributed to astrocyte activation and axonal regeneration after acute SCI. Moreover, Que up-regulated the expression of BDNF, but reduced p-JNK2 and p-STAT3 expression after acute SCI. Taken together, Que promoted locomotor and electrophysiological functional recovery, astrocyte activation and axonal regeneration after acute SCI, possibly through BDNF and JAK2/STAT3 signaling pathways.

Comparative study on tribological mechanisms of polyimide composites when sliding against medium carbon steel and NiCrBSi.

Tribological behaviors of various polyimide (PI) composites when rubbing with medium carbon steel (MCS35) and NiCrBSi, were comprehensively investigated. When the conventional PI composite filled with carbon fibers and graphite was concerned, the carbon-based tribofilm formed on NiCrBSi surface resulted in obvious friction- and wear-reduction. However, no lubricating tribofilm was formed on MCS35 surface. Chelation of polymeric molecular radicals with the metallic counterparts was identified on the worn surfaces. Theoretical calculations corroborated that the Ni-based metal-organic compound showed a higher stability than the Fe-based one. With respect to the sliding of the hybrid nanocomposites containing silica or h-BN nanoparticles, the nanoparticles released onto the interface significantly mitigated tribo-oxidation of metallic counterparts, and were finally tribo-sintered into a compact layer after being mixed with remnant polymer and tribo-oxidation products. The effect of counterpart material was less pronounced for the tribological mechanisms of the nanocomposites than for the conventional composite.

MicroRNA-99a regulates early chondrogenic differentiation of rat mesenchymal stem cells by targeting the BMPR2 gene.

Mesenchymal stem cells (MSCs) are candidates for the regeneration of articular cartilage as they possess the potential for chondrogenic differentiation. MSCs are easily obtained and expanded in vitro. Specific microRNAs (miRNAs) that regulate chondrogenesis have yet to be identified and the mechanisms involved remain to be defined. The miRNAs regulate biological processes by binding target mRNA to reduce protein synthesis. In this study, we show that expression of miR-99a and miR-125b-3p were increased during early chondrogenic differentiation of MSCs (rMSCs) derived from the Norwegian brown rat (Rattus norvegicus). MiR-99a knockdown promoted proteoglycan deposition and increased the expression of ACAN and COL2A1 during early chondrogenic differentiation. MiR-99a knockdown promoted early chondrogenic differentiation of rMSCs. A dual-luciferase reporter gene assay showed that miR-99a targeted a putative binding site in the 3'-UTR of bone morphogenetic protein (BMP) receptor type 2 (BMPR2). Overexpression of miR-99a reduced the expression levels of BMPR2 protein. The expression of total p38 and p-p38 increased at 7 and 14 days during early chondrogenic differentiation of rMSCs. Reduction in levels of total p38 and p-p38 protein followed miR-99a overexpression during early chondrogenic differentiation of rMSCs. BMPR2 silencing reversed the effects of miR-99a inhibition on proteoglycan deposition and protein expression of ACAN, COL2A1, total p38 and p-p38 during early chondrogenic differentiation of rMSCs. In conclusion, the findings of these in vitro studies in rat MSCs support a role for miR-99a as a negative regulator of early chondrogenic differentiation by directly targeting the BMPR2 gene at an early stage.

Reconstruction of atonic bladder innervation after spinal cord injury: A bladder reflex arc with afferent and efferent pathways.

Background Establishing bladder reflex arcs only with the efferent pathway to induce micturition after spinal cord injury (SCI) has been successful. However, the absence of sensory function and micturition desires can lead to serious complications. Objectives To reconstruct a bladder reflex arc with both afferent and efferent pathways to achieve atonic bladder innervation after SCI. Methods A reflex arc was established by microanastomosis of the S2 dorsal root to the peripheral process of the L5 dorsal ganglion and the L5 ventral root to the S2 ventral root. The functions of the reflex arc were evaluated using electrophysiology, wheat germ agglutinin-horseradish peroxidase (WGA-HRP) tracing, and calcitonin gene-related peptide (CGRP) immunocytochemistry analysis. Hind-paw motion was evaluated by CatWalk gait. Results Compound action potentials and compound muscle action potentials were recorded at the right L5 dorsal root following electrical stimulation of right S2 dorsal root. Similar to the control side, these were not significantly different before or after the spinal cord destruction between L6 and S4. WGA-HRP tracing and CGRP immunocytochemistry showed that construction of the afferent and efferent pathways of the bladder reflex arc encouraged axonal regeneration of motor and sensory nerves, which then made contact with the anterior and posterior horns of the spinal cord, ultimately reestablishing axoplasmic transportation. Gait analysis showed that at 3 months following the operation, only the regularity index was significantly different as compared with 1 day before the operation, other parameters showing no difference. Conclusion Bladder reflex arc with the afferent and efferent pathways reconstructs the micturition function without great influence on the motion of leg.