Chengqi He

Effects of Pulsed Electromagnetic Fields on Bone Mass and Wnt/β-Catenin Signaling Pathway in Ovariectomized Rats

BACKGROUND AND AIMS The therapeutic effects of pulsed electromagnetic fields (PEMFs) on osteoporosis have been documented. However, the precise mechanisms by which PEMFs elicit these favorable biological responses are still not fully understood. This study aimed to systematically investigate the effects of PEMFs on bone mass and Wnt/β-catenin signaling pathway in ovariectomized rats. METHODS Thirty 3-month-old female Sprague Dawley rats were randomly assigned to one of three groups: sham-operated control (sham), ovariectomy (OVX), and ovariectomy with PEMFs treatment (PEMFs). One week following ovariectomy surgery, rats in the PEMFs group were exposed to PEMFs for 40 min/day, 5 days/week, for 12 weeks. RESULTS After 12-week interventions, serum 17β-estradiol and bone-specific alkaline phosphatase levels increased in the PEMFs group. Bone mineral density of the femur and the fifth lumbar vertebral body also increased in the PEMFs group. Histomorphometrical studies showed that PEMFs improved trabecular area, trabecular width, and trabecular number by 77.50%, 17.38% and 51.06%, respectively, and reduced trabecular separation by 44.28% compared with the OVX group. Biomechanical studies showed that PEMFs increased maximum load and energy to failure in the fifth lumbar vertebral body. Quantitative real-time RT-PCR analysis showed that PEMFs increased the mRNA expressions of Wnt3a, low-density lipoprotein receptor-related protein 5(LRP5), β-catenin, c-myc and runt-related gene 2 (Runx2), and reduced dickkopf1 (DKK1) in ovariectomized rats. However, mRNA expression of Axin2 was not affected by PEMFs. CONCLUSIONS PEMFs can prevent ovariectomy-induced bone loss and deterioration of bone microarchitecture and strength, at least partly, through activation of Wnt/β-catenin signaling pathway.

Functional magnetic resonance imaging study on dysphagia after unilateral hemispheric stroke: a preliminary study

Background: Swallowing dysfunction is common and disabling after acute stroke; however, the mechanism of dysphagia or recovery of swallowing from dysphagia remains uncertain. The purpose of this study was to explore cerebral activation of swallowing in dysphagia using functional MRI (fMRI) to compare the functional anatomy of swallowing in unilateral hemispheric stroke patients and healthy adults. Methods: In total, five left hemispheric stroke patients with dysphagia, five right hemispheric stroke patients with dysphagia and 10 healthy controls were examined with event related fMRI while laryngeal swallow related movements were recorded. Data were processed using the general linear model. Results: A multifocal cerebral representation of swallowing was identified predominantly in the left hemisphere, in a bilateral and asymmetrical manner. Cerebral activation during swallowing tasks was localised to the precentral, postcentral and anterior cingulate gyri, insula and thalamus in all groups. Activation of volitional swallowing in dysphagic unilateral hemispheric stroke patients might require reorganisation of the dominant hemispheric motor cortex, or a compensatory shift in activation to unaffected areas of the hemisphere. Conclusions: The results indicate that unilateral stroke of either cerebral hemisphere can produce dysphagia. Effective recovery is associated with cerebral activation related to cortical swallowing representation in the compensating or recruited areas of the intact hemisphere. Functional MRI is a useful method for exploring the spatial localisation of changes in neuronal activity during tasks that may be related to recovery. Therefore, the subsequent information gleaned from changes in neural plasticity could be useful for assessing the prognosis of dysphagic stroke.

Coffee consumption and risk of fractures: a meta-analysis

Introduction Recent studies have indicated higher risk of fractures among coffee drinkers. To quantitatively assess the association between coffee consumption and the risk of fractures, we conducted this meta-analysis. Material and methods We searched MEDLINE and EMBASE for prospective studies reporting the risk of fractures with coffee consumption. Quality of included studies was assessed with the Newcastle Ottawa scale. We conducted a meta-analysis and a cumulative meta-analysis of relative risk (RR) for an increment of one cup of coffee per day, and explored the potential dose-response relationship. Sensitivity analysis was performed where statistical heterogeneity existed. Results We included 10 prospective studies covering 214,059 participants and 9,597 cases. There was overall 3.5% higher fracture risk for an increment of one cup of coffee per day (RR = 1.035, 95% CI: 1.019-1.052). Pooled RRs were 1.049 (95% CI: 1.022-1.077) for women and 0.910 (95% CI: 0.873-0.949) for men. Among women, RR was 1.055 (95% CI: 0.999-1.114) for younger participants, and 1.047 (95% CI: 1.016-1.080) for older ones. Cumulative meta-analysis indicated that risk estimates reached a stabilization level (RR = 1.035, 95% CI: 1.019-1.052), and it revealed a positive dose-response relationship between coffee consumption and risk of fractures either for men and women combined or women specifically. Conclusions This meta-analysis suggests an overall harm of coffee intake in increasing the risk of fractures, especially for women. But current data are insufficient to reach a convincing conclusion and further research needs to be conducted.

Pulsed electromagnetic field stimulates osteoprotegerin and reduces RANKL expression in ovariectomized rats

Pulsed electromagnetic field (PEMF) has been shown to increase bone mineral density in osteoporosis patients and prevent bone loss in ovariectomized rats. But the mechanisms through which PEMF elicits these favorable biological responses are still not fully understood. Receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) are cytokines predominantly secreted by osteoblasts and play a central role in differentiation and functional activation of osteoclasts. The purpose of this study was to investigate the effects of PEMF on RANKL and OPG expression in ovariectomized rats. Thirty 3-month-old female Sprague–Dawley rats were randomly divided into three groups: sham-operated control (Sham), ovariectomy control (OVX), and ovariectomy with PEMF treatment (PEMF). After 12-week interventions, the results showed that PEMF increased serum 17β-estradiol level, reduced serum tartrate-resistant acid phosphatase level, increased bone mineral density, and inhibited deterioration of bone microarchitecture and strength in OVX rats. Furthermore, PEMF could suppress RANKL expression and improve OPG expression in bone marrow cells of OVX rats. In conclusion, this study suggests that PEMF can prevent ovariectomy-induced bone loss through regulating the expression of RANKL and OPG.

The effect of whole body vibration on balance, gait performance and mobility in people with stroke: a systematic review and meta-analysis

Objective: To examine the effect of whole body vibration on balance, gait performance and mobility among people with stroke. Method: A systematic review was conducted by two independent reviewers who completed the article search and selection. We included randomized controlled trials published in English examining effects of whole body vibration on balance, gait, mobility, muscle strength and muscle tone in adults with a clinical diagnosis of stroke. Articles were excluded if they were research studies on people with other primary diagnosis, abstracts published in the conferences or books. The Cochrane risk of bias tool was used to assess the methodological quality of the selected studies. Data source: Sources included Cochrane Central Register of Controlled Trials, Pubmed, MEDLINE, CINAHL, EMBASE, PEDro, PsycINFO, Science Citation Index, ClinicalTrials.gov, Current Controlled Trials, Stroke Trials Registry, and reference lists of all relevant articles. Result: Eight randomized controlled trials (nine articles) involving 271 participants were included in this meta-analysis. No significant improvement was found regarding Berg balance scale (SMD=-0.08, 95%CI=-1.35 to 1.19, P=0.91), mobility (SMD=0.45, 95%CI=-0.46 to 1.37, P=0.33), maximal isometric contracion of knee extension strength (SMD=0.23, 95%CI=-0.27 to 0.74, P=0.36), and maximal isometric contracion of knee extension strength (SMD=0.09, 95%CI=-0.38 to 0.56, P=0.71). Conclusion: There was no evidence for effects of whole body vibration on balance in people with stroke. Effects of whole body vibration on mobility and gait performance remain inconclusive. More large and high-quality trials are required.

Pulsed electromagnetic fields on postmenopausal osteoporosis in Southwest China: a randomized, active-controlled clinical trial.

A randomized, active-controlled clinical trial was conducted to examine the effect of pulsed electromagnetic fields (PEMFs) on women with postmenopausal osteoporosis (PMO) in southwest China. Forty-four participants were randomly assigned to receive alendronate or one course of PEMFs treatment. The primary endpoint was the mean percentage change in bone mineral density of the lumbar spine (BMDL), and secondary endpoints were the mean percentage changes in left proximal femur bone mineral density (BMDF), serum 25OH vitamin D3 (25(OH)D) concentrations, total lower-extremity manual muscle test (LE MMT) score, and Berg Balance Scale (BBS) score. The BMDL, BMDF, total LE MMT score and BBS score were recorded at baseline, 5, 12, and 24 weeks. Serum concentrations of 25(OH)D were measured at baseline and 5 weeks. Using a mixed linear model, there was no significant treatment difference between the two groups in the BMDL, BMDF, total LE MMT score, and BBS score (P ≥ 0.05). For 25(OH)D concentrations, the effects were also comparable between the two groups (P ≥ 0.05) with the Mann-Whitneys U-test. These results suggested that a course of PEMFs treatment with specific parameters was as effective as alendronate in treating PMO within 24 weeks.

Structural and functional changes mapped in the brains of amyotrophic lateral sclerosis patients with/without dysphagia: A pilot study

The purpose of this study was to explore cerebral structural and functional changes in amyotrophic lateral sclerosis (ALS) patients with or without dysphagia compared with healthy adults. In total, five ALS patients with dysphagia, five ALS patients without dysphagia and 10 healthy controls were evaluated using diffusion tensor magnetic resonance imaging (DTI) and event-related functional magnetic resonance imaging (fMRI) while laryngeal swallow-related movements were recorded. The fMRI data were analysed using the general linear model to gain the differential statistical map (two-sample t-test) for each group. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were calculated within the masks that corresponded to the different statistical functional maps of intergroup comparisons. During the voluntary saliva swallowing, prominent activation of foci corresponded to the primary sensorimotor (SM) cortex in both ALS and controls, while decreased activation of the SM cortex was observed in ALS patients with dysphagia. DTI analysis revealed that FA was significantly reduced and MD was typically increased in the posterior limb of the internal capsule, thalamus, and anterior cingulate gyrus, as well as in the insula of ALS patients compared with controls. However, in ALS patients with dysphagia, FA and MD were more sensitive to these changes than ALS patients without dysphagia. This study highlights the potential of DTI and fMRI for monitoring structural degeneration and functional changes in patients with ALS. This study is the first to demonstrate that cerebral activation map changes correspond to distribution patterns of diffusion abnormalities. Combined non-invasive neuroimaging techniques may be useful tools to assess prognosis and study rehabilitation strategies for dysphagic ALS patients, especially for patients who are MRI-negative by conventional methods.

Effects of whole-body vibration training with quadriceps strengthening exercise on functioning and gait parameters in patients with medial compartment knee osteoarthritis: a randomised controlled preliminary study

OBJECTIVE To compare the effects of whole-body vibration training (WBVT) with quadriceps strengthening exercise (QSE) with QSE alone on functioning and gait parameters in patients with medial compartment knee osteoarthritis. DESIGN Randomised controlled preliminary study. SETTING Department of Rehabilitation Medicine, West China Hospital, Chengdu, Sichuan, Peoples Republic of China. SUBJECTS Thirty-nine patients with medial compartment knee osteoarthritis. INTERVENTIONS Participants were assigned at random to one of two groups. MAIN MEASURES Visual analogue scale (VAS) for pain, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), timed up and go test (TUG), 6-minute walk distance test (6MWD), and three-dimensional gait analysis during level walking at baseline, 12 weeks and 16 weeks (follow-up). RESULTS Compared with baseline, significant improvements in VAS, all WOMAC scales, TUG, 6MWD and all spatiotemporal parameters were seen in both the WBVT+QSE group and the QSE alone group at 12 and 16 weeks. However, the WBVT+QSE group showed greater improvements than the QSE alone group in WOMAC scales (physical function), TUG, 6MWD and cadence at 12 weeks. No differences were found between the WBVT+QSE and QSE alone groups in VAS, WOMAC scales (pain, stiffness), kinematic and kinetic gait parameters, and other spatiotemporal parameters at 12 weeks and 16 weeks. CONCLUSION Over a 3-month period, WBVT in combination with QSE improved symptoms, physical function and spatiotemporal parameters in patients with medial compartment knee osteoarthritis, and led to greater improvement than QSE alone in WOMAC scales (physical function), TUG, 6MWD and cadence.

Effects of pulsed electromagnetic fields on the mRNA expression of RANK and CAII in ovariectomized rat osteoclast-like cell.

This study was designed to determine the effects of pulsed electromagnetic fields (PEMF) on the mRNA expression of the receptor activator of NF-κ-B (RANK) and carbonic anhydrase II (CA II) in ovariectomized rat osteoclast-like cells. Marrow cells were harvested from femora and tibiae of rats, from which the ovaries had been totally excised, and cultured in 6-well chamber slides. After 1 day of incubation, the marrow cells were exposed to PEMF for 3 days with 3.8 mT, 8 Hz, and 40 min per day. Osteoclast-like cells were confirmed by both tartrate resistant acid phosphatase (TRAP) stain and bone resorption assay. The expression of RANK and CA II mRNA was determined with real-time fluorescent-nested quantitative polymerase chain reaction. Compared with the sham group, the level of serum estradiol in the ovariectomized group was significantly decreased ( p < 0.05). The numbers of multinucleated, TRAP-positive osteoclast-like cells and resorption pits formed were observed. In invitro study, the expression of RANK and CA II were measured in sham, ovariectomized without PEMF, and ovariectomized with PEMF treatment. Compared with the ovariectomized (PEMF) experimental group and sham group, CA II mRNA expression was significantly increased in the ovariectomized control group ( p < 0.05, 0.01, respectively). Compared with the sham group, RANK mRNA expression was significantly increased in the ovariectomized control group ( p < 0.05). These data suggest that PEMF could regulate the expression of RANK and CA II mRNA in the marrow culture system.

Effects of electroacupuncture on bone mineral density, oestradiol level and osteoprotegerin ligand expression in ovariectomised rabbits

Objectives To investigate the effects of electroacupuncture (EA) on the oestradiol level, bone mineral density and osteoprotegerin ligand (OPGL) expression, and to explore whether EA might be a complementary method to prevent and treat osteoporosis. Methods A total of 21 New Zealand rabbits were randomly divided into three groups: a normal control (NC) group undergoing no surgery or EA; an ovariectomised (OVX) group, in which rabbits were ovariectomised but did not receive EA; an EA group, in which rabbits were ovariectomised and treated with EA. Acupuncture was applied at ST35, BL20 and BL23 points bilaterally. EA (10 Hz, 2 mA) was applied bilaterally at BL20 and BL23 for 30 min a day for 14 days. After 14 days, all animals were killed. OPGL expression level was determined by immunohistochemistry. Blood serum levels of oestradiol were measured by ELISA and bone mineral density was detected by dual-energy x-ray absorptiometry. Results After ovariectomy, the bone mineral density and oestradiol level decreased significantly in the OVX group compared with the NC group (p=0.001), whereas the OPGL expression level increased. After EA, the bone mineral density and oestradiol level increased compared with the OVX group (p=0.049 and p=0.012, respectively). The OPGL level OPGL level in the EA group was lower than that in the OVX group (p=0.022). Conclusions EA restored bone mineral density towards normal and was associated with increased plasma oestradiol level and reduced OPGL expression in an ovariectomised rabbit model of osteoporosis.