Regulation of skeletal myogenesis in C2C12 cells through modulation of Pax7, MyoD, and myogenin via different low-frequency electromagnetic field energies.

BACKGROUND: A low-frequency electromagnetic field (LF-EMF) exerts important biological effects on the human body. OBJECTIVE: We previously studied the immunity and atrophy of gastrocnemius muscles in rats with spinal cord injuries and found that LF-EMF with a magnetic flux density of 1.5 mT exerted excellent therapeutic and preventive effects on reducing myotubes and increasing spatium intermusculare. However, the effects of LF-EMF on all stages of skeletal myogenesis, such as activation, proliferation, differentiation, and fusion of satellite cells to myotubes as stimulated by myogenic regulatoryfactors (MRFs), have not been fully elucidated. METHODS: This study investigated the optimal LF-EMF magnetic flux density that exerted maximal effects on all stages of C2C12 cell skeletal myogenesis as well as its impact on regulatory MRFs. RESULTS: The results showed that an LF-EMF with a magnetic flux density of 2.0 mT could activate C2C12 cells and upregulate the proliferation-promoting transcription factor PAX7. On the other hand, 1.5 mT EMF could upregulate the expression of MyoD and myogenin. CONCLUSION: LF-EMF could prevent the disappearance of myotubes, with different magnetic flux densities of LF-EMF exerting independent and positive effects on skeletal myogenesis such as satellite cell activation and proliferation, muscle cell differentiation, and myocyte fusion.

Role of melatonin in the dynamics of acute spinal cord injury in rats.

Melatonin is well-documented to have the ability of reducing nerve inflammation and scavenging free radicals. However, the therapeutic effect of melatonin on spinal cord injury has not been fully described. In this study, we assessed the effect of melatonin on T9 spinal cord injury established by Allen method in rats. Melatonin deficiency significantly delayed the recovery of sensory and motor functions in SCI rats. Treatment with melatonin significantly alleviated neuronal apoptosis and accelerated the recovery of spinal cord function. These results suggest that melatonin is effective to ameliorate spinal cord injury through inhibition of neuronal apoptosis and promotion of neuronal repair.

Melatonin Synergizes With Methylprednisolone to Ameliorate Acute Spinal Cord Injury.

Methylprednisolone (MP) is the drug of choice for treating spinal cord injury (SCI), but the aggressive dosage regimen used often results in adverse side effects. Therefore, MP should be combined with other drugs to lower the required dose. Melatonin is effective in alleviating nerve damage and inhibiting axonal degeneration. The combination of melatonin and half-dose methylprednisolone (HMP) for spinal cord injury treatment has never been reported. In this study, we established a rat model of T9 spinal cord injury by the Allen's method and assessed the synergistic therapeutic effects of melatonin and HMP by factorial design. Our results demonstrated that melatonin could synergize with HMP to ameliorate acute SCI through PI3K-AKT1 pathway. Combining melatonin with HMP significantly reduced the standard-dose of methylprednisolone and limited its adverse reactions, representing a promising option for treating acute SCI.

Preliminary study on the electromagnetic field treatment of osteoporosis in rats.

OBJECTIVE: In our study, the influence of PEMF on skeleton morphology and bone metabolism on rats with disuse osteoporosis was investigated, and the possibility of using it for the treatment of disuse osteoporosis was explored. METHODS: The rats in the ALN group were treated with alendronate, and the rats in the PEMF group were exposed to pulsed electromagnetic fields (3.82 mT, 10 Hz) for 40 mind-1. Rats were sacrificed by the end of 2, 4, 8 and 12 weeks, and serum and right leg bones were collected. Serum BMP-2, BGP concentrations and bone metabolism and biomechanical parameters were measured. RESULTS: The bone structural mechanical indices and material mechanical indices of the right femur in all groups of mice during weeks 2 and 4 were decreased. At week 8 the bone structural mechanical index and maximum stress of the right femur in the ALN group were markedly raised compared with the CON group (P< 0.01). Only maximum stress and strain were improved in the ALN group and had a significant difference (P< 0.05) at week 12. The serum BGP and BMP-2 concentration in the PEMF and ALN groups was increased (P< 0.05) at week 2, but this increase was not synchronized. After 8 weeks, BGP and BMP-2 level in the PEMF group was observably elevated (P<0.01) in contrast to the ALN group. CONCLUSION: From the experimental time interval analysis, PEMF can improve the mechanical stability of bone structure more gently and permanently than alendronate.

Association of high PDPN expression with pulmonary metastasis of osteosarcoma and patient prognosis.

Podoplanin (PDPN) is an important positive regulator of platelet aggregation and functions as a lymphatic endothelial marker. PDPN has been observed to be expressed in human tumor tissues and various cancer cell lines. In the present study, PDPN expression in patients with primary osteosarcoma was assessed at the mRNA and protein levels, and the associations between PDPN expression and pulmonary metastasis (PM) and prognosis were examined. Reverse transcription-quantitative PCR (RT-qPCR) analysis was used to detect the expression levels of PDPN in primary osteosarcoma tissues and paired normal bone tissues (n=20 pairs). In addition, immunohistochemical analysis of PDPN expression was performed in 168 paraffin-embedded osteosarcoma tissue specimens and 23 matched normal tissues. The RT-qPCR results revealed higher mRNA expression levels of PDPN in patients with PM compared with patients without PM. Further survival analyses identified Enneking stage and PM as two independent prognostic indicators. Finally, univariate analysis revealed that high PDPN protein expression was significantly associated with Enneking stage and PM in patients with osteosarcoma.

Neuroprotective effect of omega-3 fatty acids on spinal cord injury induced rats.

INTRODUCTION: In this study, the effects of omega-3 fatty acids were examined in a rat model of spinal cord injury. METHODS: The rats were classified into sham, control, spinal cord injury plus 50 mg/kg Omega-3 fatty acids and spinal cord injury plus 100 mg/kg Omega-3 fatty acids. The levels of oxidative, apoptotic, and inflammatory markers were examined in each of these groups. RESULTS: Altered lipid peroxidation, reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase were normalized. Omega-3 fatty acid supplementation decreased tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels by >50%. TNF-α and IL-6 mRNA expression were reduced. Caspase-3, p53, bax, and pro-NGF mRNA expression levels were increased by 1.3-, 1.4-, 1.2-, and 0.9-fold, respectively, whereas bcl-2 mRNA expression was decreased by 0.77-fold in control rats. Omega-3 fatty acid supplementation decreased p53, caspase-3, bax, and pro-NGF mRNA expression by >40%, while the level of bcl-2 mRNA expression was increased by 286.9%. Omega-3 fatty acid supplementation decreased caspase-3 and p53 protein expression by >30%. CONCLUSION: Taken together, our results suggested that omega-3 fatty acid supplementation reduced oxidative stress, apoptosis, and the levels of inflammatory markers in ischemia-reperfusion-induced rats.

LncRNA-SULT1C2A regulates Foxo4 in congenital scoliosis by targeting rno-miR-466c-5p through PI3K-ATK signalling.

Congenital scoliosis (CS) is the result of anomalous vertebrae development, but the pathogenesis of CS remains unclear. Long non-coding RNAs (lncRNAs) have been implicated in embryo development, but their role in CS remains unknown. In this study, we investigated the role and mechanisms of a specific lncRNA, SULT1C2A, in somitogenesis in a rat model of vitamin A deficiency (VAD)-induced CS. Bioinformatics analysis and quantitative real-time PCR (qRT-PCR) indicated that SULT1C2A expression was down-regulated in VAD group, accompanied by increased expression of rno-miR-466c-5p but decreased expression of Foxo4 and somitogenesis-related genes such as Pax1, Nkx3-2 and Sox9 on gestational day (GD) 9. Luciferase reporter and small interfering RNA (siRNA) assays showed that SULT1C2A functioned as a competing endogenous RNA to inhibit rno-miR-466c-5p expression by direct binding, and rno-miR-466c-5p inhibited Foxo4 expression by binding to its 3' untranslated region (UTR). The spatiotemporal expression of SULT1C2A, rno-miR-466c-5p and Foxo4 axis was dynamically altered on GDs 3, 8, 11, 15 and 21 as detected by qRT-PCR and northern blot analyses, with parallel changes in Protein kinase B (AKT) phosphorylation and PI3K expression. Taken together, our findings indicate that SULT1C2A enhanced Foxo4 expression by negatively modulating rno-miR-466c-5p expression via the PI3K-ATK signalling pathway in the rat model of VAD-CS. Thus, SULT1C2A may be a potential target for treating CS.

MicroRNA signature of air pollution exposure-induced congenital defects.

Air pollution exposure has been increasing extensively and there are evidence suggesting that exposure to air pollution during pregnancy can lead to congenital defects in the offspring. Recent findings suggested that microRNAs (miRNAs) might play important roles in the pathogenesis of developmental defects. However, the miRNAs profile pattern in the air pollution-exposed embryos remains unknown. RNA sequencing was performed to determine the differentially expressed miRNAs in the rat embryos (gestation day 9) with or without air pollution exposure. The potential functions and the associated mechanisms of these differentially expressed miRNAs were determined using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analyses. The regulatory networks of mRNA-miRNA interactions were also reconstructed. As compared with the control group, a total of 291 miRNAs were differentially expressed in the rat embryos from the air pollution-exposed group, in which 204 and 87 miRNAs were significantly downregulated and upregulated, respectively. These miRNAs were predicted to deregulate mitotic spindle organization, cellular respiration, glycolate metabolism, and proteasome. Extensive regulation of target genes by miR-346, miR-504, miR-214-3p and miR-1224 was also predicted. Our results suggested that miRNAs may play crucial roles in the pathogenesis of air pollution-induced congenital spinal defects through deregulating multiple biological processes.

Melatonin protected against the detrimental effects of microRNA-363 in a rat model of vitamin A-associated congenital spinal deformities: Involvement of Notch signaling.

Congenital spinal deformities are a result of defective somitogenesis and are associated with vitamin A deficiency (VAD). However, the molecular mechanisms of VAD-associated congenital spinal deformities remain largely unknown. Increasing number of studies suggested that microRNAs and melatonin played important roles in the development of congenital spinal deformities. In this study, we showed that the whole-embryo expression of miR-363 was upregulated in VAD rats. Furthermore, we demonstrated that miR-363 inhibited the proliferation and neuronal differentiation of primary cultured NSCs, accompanied by downregulation of Notch1. To this end, melatonin suppressed miR-363 expression and rescued the effects of miR-363 on NSC proliferation and neuronal differentiation together with restoration of Notch signaling. The present study provided new insights into the mechanism of VAD-associated spinal deformities and the therapeutic effect of melatonin that may lead to novel understanding of the molecular mechanisms of congenital spinal deformities.

Identification of Competing Endogenous RNA Regulatory Networks in Vitamin A Deficiency-Induced Congenital Scoliosis by Transcriptome Sequencing Analysis.

BACKGROUND/AIMS: Congenital scoliosis (CS) is a result of anomalous development of vertebrae and is frequently associated with somitogenesis malformation. Although noncoding RNAs (ncRNAs) have been recently determined to be involved in the pathogenesis of CS, the competing endogenous RNA (ceRNA) regulatory networks in CS remain largely unknown. METHODS: Sequencing was conducted to explore the ncRNA expression profiles in rat embryos (gestation day 9) following vitamin A deficiency (VAD) (n = 9 for the vitamin A deficiency-induced congenital scoliosis (VAD-CS) group and n = 4 for the control group). Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was conducted to verify the expression levels of selected mRNAs, long noncoding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). Bioinformatics analysis was used to discover the possible relationships and functions of the ceRNAs. RESULTS: A total of 749 mRNAs, 56 miRNAs, 685 lncRNAs, and 70 circRNAs were identified to have significantly different expression levels in the two groups. Wnt, PI3K-ATK, FoxO, EGFR, and mTOR were found to be the most significant pathways involved in VAD-CS pathogenesis. The circRNA/miRNA/mRNA and lncRNA/miRNA/mRNA networks of CS were built, and the gene expression mechanisms regulated by ncRNAs were unveiled via the ceRNA regulatory networks. CONCLUSION: We comprehensively identified ceRNA regulatory networks of embryonic somite development in VAD-CS as well as revealed the contribution of different ncRNA expression profiles. Our data demonstrate the association between mRNAs and ncRNAs in the pathogenic mechanism of CS.

Effects of pulsed electromagnetic fields on histomorphometry and osteocalcin in disuse osteoporosis rats.

OBJECTIVE: Bone histomorphometry and the concentration of the serum osteocalcin expression were observed in disuse osteoporosis (DOP) rats in order to explore the mechanism of pulsed electromagnetic fields in treating DOP. METHODS: Female SD rats, weighing 250 ∼ 280 g, were randomly divided into 4 groups: a control group and three experimental groups. The right hindlimbs of all the rats were immobilized by tibia-tail fixation, except for those in the INT group. The ALN group rats were given an alendronate sodium (1 mg kg-1 d-1) treatment, and the rats in the PEMF group received PEMF irradiation. Bone histomorphometry and the concentration of serum osteocalcin expression were detected in 2, 4, 8, and 12 weeks. RESULTS: Four weeks after modeling, as compared with the DOP group, the %Tb-Ar and Tb-N in the ALN group were increased, and the difference was significant (P< 0.05 or P< 0.01). At 8 weeks, as compared with the DOP group, the %Tb-Ar and Tb-N in the ALN group and the PEMF group both increased, and there was a significant difference (P< 0.05 or P< 0.01). At 12 weeks, as compared with the DOP group, the BGP serum concentration of the ALN group was reduced, and there was a statistical difference (P< 0.05). CONCLUSION: Pulse electromagnetic field with drug can prevent disuse osteoporosis by changing the bone microstructure. In the long run, PEMF improves the mechanical performance of biological structures better than alendronate sodium does. PEMF may influence the process of bone remodeling by promoting the level of osteocalcin.

Predicting factors associated with frailty in aged patients with bone-arthrosis pain in the clinic.

OBJECTIVES: To identify frail and pre-frail patients in a group of patients older than 60 years. METHODS: The phenotype model of Fried's method was used to identify frailty and pre-frailty in total of 78 participants. Cognitive ability and psychosocial function tests were also given to 59 of the 78 patients. RESULTS: Prevalence of frailty and pre-frailty was 14.1% (11/78) and 46.2% (36/78), respectively. Of the 5 phenotype variables, weak grip strength was the most commonly seen variable with 53.8% of all participants and 100% in the frail group. Low energy expenditure, however, was not self-reported by any participant in the current study (0%). Prevalence of frailty in the present study is associated with chronological age. The current study indicates that 4 phenotypic variables (unintentional weight loss, self-reported exhaustion, gait speed and grip strength) contribute to the development to frailty, and that cognitive impairment and psychosocial frailty also predict frailty or pre-frailty in the patients older than 60 years old irrespective of chronic pain or osteoarthritis. The findings of the current study suggest frailty and pre-frailty are common in senior Chinese patients with chronic diseases. CONCLUSION: Recognition and identification of frailty in a rehabilitation clinic or hospital might help physicians to provide appropriate counseling to patients and families about adverse outcomes of certain treatments such as surgery, and could optimize management of coexisting chronic diseases that might contribute to or be affected by frailty.

Acupuncture for the Treatment of Oculomotor Paralysis: A Pilot Randomised Controlled Trial.

This study consisted of a single centre randomised controlled trial with two parallel arms: an acupuncture group (n = 20) with 27 affected eyes and a sham group (n = 20) with 23 affected eyes. Participants in the acupuncture group received acupuncture treatment once daily, three times weekly for four weeks. Participants assigned to the control group received sham acupuncture, the same protocol as that used for the acupuncture group but without insertion of needles into the skin. The primary outcome measure was the cervical range of motion (CROM) score. Secondary outcome measures were the palpebral fissure size, response rate, and adverse events. All 40 participants completed the study. In the comparison of acupuncture and sham acupuncture, a significant difference was observed between acupuncture and sham acupuncture in CROM score (21.37 ± 15.16 and 32.21 ± 19.54, resp.) (P < 0.05) and palpebral fissure size (7.19 ± 2.94 and 5.41 ± 2.45, resp.) (P < 0.05). Response rate was also significantly different in the acupuncture group (P < 0.05). No adverse events were reported in both groups in this study. In summary, it was demonstrated that acupuncture had a feasibility positive effect on oculomotor paralysis.

Healthcare Associated Infections of Methicillin-Resistant Staphylococcus aureus: A Case-Control-Control Study.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most widespread and dangerous pathogens in healthcare settings. We carried out this case-control-control study at a tertiary care hospital in Guangzhou, China, to examine the antimicrobial susceptibility patterns, risk factors and clinical outcomes of MRSA infections. METHODS: A total of 57 MRSA patients, 116 methicillin-susceptible Staphylococcus aureus (MSSA) patients and 102 S. aureus negative patients were included in this study. We applied the disk diffusion method to compare the antimicrobial susceptibilities of 18 antibiotics between MRSA and MSSA isolates. Risk factors of MRSA infections were evaluated using univariate and multivariate logistic regression models. We used Cox proportional hazards models and logistic regression analysis to assess the hospital stay duration and fatality for patients with MRSA infections. RESULTS: The MRSA group had significantly higher resistance rates for most drugs tested compared with the MSSA group. Using MSSA patients as controls, the following independent risk factors of MRSA infections were identified: 3 or more prior hospitalizations (OR 2.8, 95% CI 1.3-5.8, P = 0.007), chronic obstructive pulmonary disease (OR 5.9, 95% CI 1.7-20.7, P = 0.006), and use of a respirator (OR 3.6, 95% CI 1.0-12.9, P = 0.046). With the S. aureus negative patients as controls, use of a respirator (OR 3.8, 95% CI 1.0-13.9, P = 0.047) and tracheal intubation (OR 8.2, 95% CI 1.5-45.1, P = 0.016) were significant risk factors for MRSA infections. MRSA patients had a longer hospital stay duration and higher fatality in comparison with those in the two control groups. CONCLUSIONS: MRSA infections substantially increase hospital stay duration and fatality. Thus, MRSA infections are serious issues in this healthcare setting and should receive more attention from clinicians.

Preparation and evaluation of an Arg-Gly-Asp-modified chitosan/hydroxyapatite scaffold for application in bone tissue engineering.

Bone tissue engineering has become a promising method for the repair of bone defects, and the production of a scaffold with high cell affinity and osseointegrative properties is crucial for successful bone substitute. Chitosan (CS)/hydroxyapatite (HA) composite was prepared by in situ compositing combined with lyophilization, and further modified by arginine­glycine­aspartic acid (RGD) via physical adsorption. In order to evaluate the cell adhesion rate, viability, morphology, and alkaline phosphatase (ALP) activity, the RGD­CS/HA scaffold was seeded with bone marrow stromal cells (BMSCs). The osseointegrative properties of the RGD­CS/HA scaffold were evaluated by in vivo heterotopic ossification and in vivo bone defect repair. After 4 h culture with the RGD­CS/HA scaffold, the adhesion rate of the BMSCs was 80.7%. After 3 days, BMSCs were fusiform in shape and evenly distributed on the RGD­CS/HA scaffold. Formation of extracellular matrix and numerous cell­cell interactions were observed after 48 h of culture, with an ALP content of 0.006 ± 0.0008 U/l/ng. Furthermore, the osseointegrative ability and biomechanical properties of the RGD­CS/HA scaffold were comparable to that of normal bone tissue. The biocompatibility, cytocompatibility, histocompatibility and osseointegrative properties of the RGD­CS/HA scaffold support its use in bone tissue engineering applications.

Effect of long-term pulsed electromagnetic field exposure on hepatic and immunologic functions of rats.

BACKGROUND: In this report, the effects of long-term pulsed electromagnetic field (PEMF) exposure on hepatic and immunologic functions were examined. METHODS: Male rats were randomly divided into four groups: a control group and three experimental groups exposed to a 50-Hz PEMF at 5, 10, or 20 mT for 10 weeks. RESULTS: Compared with the control group, activities of serum alanine aminotransferase and aspartate aminotransferase and concentrations of serum, liver, and spleen Metabolism of lipid peroxidation (MDA) in the 10- and 20-mT PEMF groups were significantly increased. The activities of Glutathione peroxidase (GSH-Px) and Superoxide Dismutase (SOD) in the serum, liver, and spleen and concentrations of serum immunoglobulins were significantly decreased. CONCLUSION: These results demonstrate that long-term exposure to PEMF can lead to oxidative damage of the liver and spleen.

Multidrug-resistant Pseudomonas aeruginosa infections pose growing threat to health care-associated infection control in the hospitals of Southern China: a case-control surveillance study.

BACKGROUND: Multidrug-resistant Pseudomonas aeruginosa (MDRPA) is one of the most common agents among health care-associated infections. There is a lack of data on the clinical features of MDRPA from Southern China. METHODS: A case-control surveillance study of P aeruginosa was conducted based on surveillance from July 2008-December 2012, in 5 hospitals of Guangzhou, China. Data were analyzed by univariate analysis and multivariate logistic regression using Stata 13 (StataCorp, College Station, TX). RESULTS: Of the 348 P aeruginosa strains, the prevalence of MDRPA was 54%, and it has increased over time. Isolates of P aeruginosa showed increased resistance to most antimicrobials during this time period. Independent risk factors were tracheal intubation insertion (odds ratio [OR], 2.21; 95% confidence interval [CI], 1.16-4.23; P = .02) and use of carbapenem (odds ratio [OR], 3.36; 95% confidence interval [CI], 1.75-6.47; P < .01). The distribution of MDRPA infections was uneven among the 5 hospitals (P = .01). Being infected with MDRPA strains resulted in longer duration of hospitalization (39 vs 24 days) and higher mortality (49% vs 20%). CONCLUSION: The infections of MDRPA were severe issues. More stringent measures should be applied for those with independent predictors of MDRPA infections because they may induce adverse clinical outcomes.

Teicoplanin as an effective alternative to vancomycin for treatment of MRSA infection in Chinese population: a meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate whether teicoplanin could be an alternative to vancomycin for treatment of MRSA infection in Chinese population using a meta-analysis in randomized controlled trials. METHODS: THE FOLLOWING DATABASES WERE SEARCHED: Chinese Biomedical Literature database (CBM), Chinese Journal Full-text database (CNKI), Wanfang database, Medline database, Ovid database and Cochrane Library. Articles published from 2002 to 2013 that studied teicoplanin in comparison to vancomycin in the treatment of MRSA infected patients were collected. Overall effects, publishing bias analysis and sensitivity analysis on clinical cure rate, microbiologic eradication rate and adverse events rate were performed by using Review Manager 5.2 and Stata 11.0 softwares. RESULTS: Twelve articles met entry criteria. There was no statistically significant difference between the two groups regarding the clinical cure rate (risk ratio [RR], teicoplanin vs vancomycin, 0.94; 95% CI, 0.74~1.19; P=0.60), microbiological cure rate (risk ratio [RR], teicoplanin vs vancomycin, 0.99; 95% CI, 0.91~1.07; P=0.74) and adverse event rate (risk ratio [RR], teicoplanin vs vancomycin, 0.86; 95% CI, 0.40~1.84; P=0.70). CONCLUSIONS: The meta-analysis results indicate that the two therapies are similar in both efficacy and safety, thus teicoplanin can act as an effective alternative to vancomycin for treating patients infected by MRSA.