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The study aims to explore the effect of mesenchymal stem cells-derived exosomes (MSCs-Exo) on staurosporine (STS)-induced chondrocyte apoptosis before and after exposure to pulsed electromagnetic field (PEMF) at different frequencies. The AMSCs were extracted from the epididymal fat of healthy rats before and after exposure to the PEMF at 1 mT amplitude and a frequency of 15, 45, and 75 Hz, respectively, in an incubator. MSCs-Exo was extracted and identified. Exosomes were labeled with DiO fluorescent dye, and then co-cultured with STS-induced chondrocytes for 24 h. Cellular uptake of MSC-Exo, apoptosis, and the protein and mRNA expression of aggrecan, caspase-3 and collagenⅡA in chondrocytes were observed. The study demonstrated that the exposure of 75 Hz PEMF was superior to 15 and 45 Hz PEMF in enhancing the effect of exosomes in alleviating chondrocyte apoptosis and promoting cell matrix synthesis. This study lays a foundation for the regulatory mechanism of PEMF stimulation on MSCs-Exo in inhibiting chondrocyte apoptosis, and opens up a new direction for the prevention and treatment of osteoarthritis.
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Animals , Rats , Apoptosis , Chondrocytes , Electromagnetic Fields , Exosomes/physiology , Mesenchymal Stem Cells/metabolismABSTRACT
Introdução: O tratamento com campo eletromagnético focado de alta intensidade (HIFEM) usa ondas eletromagnéticas de baixa frequência para induzir contrações musculares, causando hipertrofia muscular e reduzindo a gordura subcutânea. Objetivo: avaliar os efeitos de um tratamento com HIFEM na celulite nos glúteos. Métodos: trinta mulheres foram recrutadas e randomizadas em 2 grupos que receberam 8 ou 12 sessões de HIFEM na região dos glúteos. A celulite foi avaliada utilizando a Cellulite Severity Scale, a Global Aesthetic Improvement Scale e um questionário de satisfação. Mudanças na composição corporal foram avaliadas com bioimpedância e medidas da circunferência do quadril. Resultados: a aparência global da região glútea das pacientes melhorou com o tratamento. Houve melhora na celulite de algumas pacientes, mas para a maioria a melhora não foi grande o suficiente para resultar em uma mudança de classificação na Cellulite Severity Scale. A satisfação foi alta e os eventos adversos foram poucos, não-graves e transitórios. Conclusão: os efeitos do tratamento com HIFEM na celulite da região glútea são sutis. Contudo, este tratamento é capaz de melhorar globalmente a aparência da região glútea, melhorando a percepção das pacientes sobre a gravidade de sua celulite
Introduction: High-intensity focused electromagnetic field treatment (HIFEM) uses low-frequency electromagnetic waves to induce supramaximal muscle contractions, causing muscle hypertrophy and reducing fat. Objective: To evaluate the effects of a HIFEM treatment for the improvement of cellulite on the buttocks. Methods: Thirty patients were divided into two groups that received eight or 12 HIFEM sessions on the buttocks for six weeks. We assessed the improvement in cellulite and the buttocks' global appearance through the Cellulite Severity Scale (CSS), the Global Aesthetic Improvement Scale (GAIS), and a satisfaction questionnaire. Changes in body composition were evaluated through bioimpedance and hip circumference measurements. Results: Patients from both groups improved the global appearance of their buttocks. Cellulite lesions of some patients improved, but for most patients, the improvement wasn't great enough to change the grade on the Cellulite Severity Scale. Patient satisfaction was high and adverse events were few, minor, and transitory. Conclusion: The effects of HIFEM on cellulite are subtle, as this treatment modality cannot address the fibrous septa that cause the depressed lesions of cellulite. Nevertheless, HIFEM procedures can improve the buttocks' global appearance, enhancing the patients' subjective perception of their cellulite.
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SUMMARY OBJECTIVE: The aim of this study was to examine the changes on the Purkinje cells in the cerebella of male rat pups born to pregnant dams that were exposed to an electromagnetic field in the prenatal period. METHODS: The first stage of the study involved 12 Sprague-Dawley rats, 6 male and 6 female, weighing between 180 and 250 g. The female rats in the experimental group were exposed to a 900-MHz electromagnetic field for 1 h at the same time every day, and no procedure was performed on the control group. Following pregnancy, six male pups from each group were divided into experimental and control groups without any procedure on the pups. After 2 months, they were sacrificed and their cerebella were removed. Histopathologically, following routine processing and fixation procedures, the cerebella were embedded in the tissue blocks. The sections taken from these blocks were stained with cresyl violet. The Purkinje cells in the cerebella were then counted on sections using the optical dissector method on an image analysis system. RESULTS: The estimation of number of the Purkinje cells in the groups revealed more cells in rats in the control group than in the experimental group. Histopathologically, Purkinje cells exhibited a normal morphological structure in the control group, while the cells in the experimental group showed damage. CONCLUSIONS: It might be asserted that the exposure of mothers to an electromagnetic field in the prenatal period may affect the development of Purkinje cells in the pup cerebella.
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Objective:To observe any regulatory effect of a pulsed electromagnetic field (PEMF) on A2A adenosine receptors (A2ARs) in the nucleus pulposus of rats with intervertebral disc degeneration (IDD), and to explore any combination with the A2ARs′ agonist-mediating ROS/PI3K/Akt signaling pathway.Methods:Fifty Sprague-Dawley rats were randomly divided into a control group, an intervertebral disc degeneration group (the model group), an A2AR agonist CGS-21680 treatment group (the agonist group), a PEMF group and a PEMF combined with CGS-21680 treatment group (the observation group). IDD was modeled in all except the rats in the control group. 100μL of CGS-21680 (100μg/kg) was injected into the L 5-6 intervertebral discs of the agonist group, while the PEMF group was given 30 minutes of PEMF intervention daily for 14 days at 1.5mT and 75Hz with a pulse width of 150μs. The observation group was injected with CGS-21680 and then given the same PEMF intervention. Primary nucleus pulposus cells from each group (50ng/mL) were cultured and the expressions of 8-OHDG, SOD, MDA and ROS were detected by immunohistochemistry, immunofluorescence or with an ELISA kit. The A2AR, PI3K, AKT and p-AKT protein levels were detected using western blotting. Results:The nucleus pulposus cells and the annulus fibrosus were obviously wrinkled, necrotic and broken in the model group but the annulus fibrosus was intact and the nucleus pulposus was almost normal in the observation group. Compared with the model group, the levels of SOD and A2AR, PI3K, p-AKT and AKT protein were higher in the agonist, PEMF and observation groups, while the expressions of MDA, ROS and 8-OHDG were weaker. The ROS level in the observation group was significantly lower than that in the agonist and PEMF groups, and the phosphorylation level of p-AKT in the observation group was significantly higher than in the agonist and PEMF groups. The average levels of SOD, A2AR, PI3K, p-AKT and AKT protein in the nucleus pulposus cells of the agonist, PEMF and observation groups were significantly higher than the IL-1β group′s average, while the average levels of MDA, ROS and 8-OHDG were significantly lower. The ROS levels in the observation group were significantly lower than in the agonist and PEMF groups, while the A2AR protein content and p-AKT phosphorylation in the observation group were significantly greater. The average Bax levels in the nucleus pulposus cells of the agonist, PEMF and observation groups were significantly lower than that in the IL-1β group, and the expression of Bcl-2 was significantly increased. There was significantly less apoptosis observed in the observation group than in the agonist and PEMF groups, while the expression of Bcl-2 was significantly higher.Conclusions:PEMF plays an anti-oxidative stress role by up-regulating A2AR activity and reducing ROS generation. Treatment with PEMF and A2AR agonist could further activate the phosphorylation of PI3K/Akt, down-regulate Bax and up-regulate Bcl-2, thus inhibiting the apoptosis of nucleus pulposus cells and alleviating the malignant progression of IDD.
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Introducción: La generación de energía eléctrica constituye uno de los indicadores más importantes de desarrollo de una nación. En ese proceso se generan campos electromagnéticos de frecuencia extremadamente baja, que pudieran afectar el corazón. Objetivo: Identificar la asociación entre el riesgo cardiovascular y la exposición a los campos electromagnéticos de frecuencia extremadamente baja. Métodos: Se realizó un estudio transversal, descriptivo en el Área de Salud 27 de Noviembre, del municipio Marianao de la provincia La Habana, en el año 2018. La muestra estuvo constituida por 152 individuos. Se les determinó el riesgo cardiovascular, según las tablas predictivas de Gaziano sin laboratorio. Se realizaron mediciones de las densidades de flujo magnético en sus viviendas. Se valoró si estas, se asociaron a la intensidad de generación de electricidad de la vecina central termoeléctrica y con el riesgo cardiovascular global de los residentes. Se utilizó correlación no paramétrica de Spearman. Resultados: El 31,6 % de la población estudiada fue evaluada con el riesgo cardiovascular alto y muy alto en su conjunto. 120 individuos estuvieron expuestos en sus viviendas a densidades del flujo magnético entre 0 y 0,9 µT. Existió una correlación estadística significativa, entre la intensidad de la corriente generada por la industria y las densidades de flujo magnético en las habitaciones usadas para dormir. Conclusiones: No se observó asociación entre el riesgo cardiovascular y las densidades de flujo magnético medidas en las viviendas. La exposición a los campos electromagnéticos de frecuencia extremadamente baja no constituyó un factor de riesgo cardiovascular para la población estudiada.
Introduction: The generation of electrical energy constitutes one of the most important indicators of development of a nation. In this process, extremely low frequency electromagnetic fields are generated, which could affect the heart. Objective: To identify the association between global cardiovascular risk and exposure to extremely low frequency electromagnetic fields. Methods: A cross-sectional, descriptive study was carried out in the Health Area November 27, of the Marianao municipality of Havana province, in 2018. The sample consisted of 152 individuals. The cardiovascular risk was determined, according to the Gaziano predictive tables without laboratory. Measurements of magnetic flux densities were made in their homes. It was assessed whether these were associated with the intensity of electricity generation at the neighboring thermoelectric plant and with the overall cardiovascular risk of the residents. Spearman's non-parametric correlation was used. Results: 31,6% of the studied population was evaluated with high and very high cardiovascular risk as a whole. 120 individuals were exposed in their homes to magnetic flux densities between 0 and 0,9 µT. There was a statistically significant correlation between the intensity of the current generated by the industry and the magnetic flux densities in the rooms used to sleep. Conclusions: No association was observed between the cardiovascular risk and the magnetic flux densities measured in the dwellings. Exposure to extremely low frequency electromagnetic fields was not a cardiovascular risk factor for the population studied.
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Objective:To analyze the changes in the transcriptome of mouse fibroblasts after exposure to extremely low frequency electromagnetic fields (ELF-EMFs) using next-generation sequencing technology, and to screen out related pathways and genes that might be involved in the regulation of fibroblast growth by ELF-EMFs.Methods:The mouse NIH/3T3 cells were divided into the radiation group and the normal control group.The cells in the radiation group were placed in a 0.2 mT, 50 Hz electromagnetic radiation system, and the cells in the normal control group was placed in the same coil system under the same conditions without power.After 24-hour culture in a cell incubator, RNA was extracted.The next-generation high-throughput sequencing technology was used to sequence the transcriptomes of the two groups, and perform gene function annotation and signal pathway database analysis on the selected differential genes.Some highly expressed genes were screened out and verified by real-time fluorescent quantitative PCR.Results:A total of 17 980 genes were identified in the transcriptome sequencing, and there were 140 significantly differentially expressed genes (DEGs), of which 120 were up-regulated and 20 were down-regulated.DEGs were enriched in enzyme catalytic activity, cell metabolism process, biological regulation, biosynthesis and so on.According to the Kyoto Encyclopedia of Genes and Genomes analysis, the DEGs mainly involved 55 pathways, among which the most enriched 10 pathways were aminoacyl-tRNA biosynthesis, platelet activation, neurotrophin signaling pathway, renin-angiotensin system, etc., closely related to cell biosynthesis.The DEGs that might be involved in the post-irradiation stress of cells were further screened out, including mitogen activated protein kinase 12 ( MAPK12), neurotrophic tyrosine kinase receptor type 3 ( NTRK3), angiotensin Ⅱ receptor type 2 ( AGTR2), vascular endothelial growth factor ( VEGF), etc.Real-time fluorescent quantitative PCR results showed that the relative expression levels of MAPK12, NTRK3, AGTR2, VEGF mRNA in the radiation group were 2.389±0.003, 2.481±0.350, 2.354±0.081, 1.559±0.110, respectively, which were significantly higher than 1.011±0.190, 1.011±0.180, 1.007±0.150, 1.008±0.153, respectively in the normal control group ( t=12.540, 6.309, 13.710, 3.078; all at P<0.05). Conclusions:After the mouse fibroblasts were interfered with ELF-EMFs, the expression levels of MAPK12, NTRK3, AGTR2, VEGF and other genes are significantly up-regulated, which mainly involve neurotrophin signaling pathway, renin-angiotensin system and other pathways.These genes and pathways may be the main way that ELF-EMFs affect fibroblasts.
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Background: Sleep is an important process of our body and a good sleep will lead to a healthy lifestyle. In medical field, students have sleep patterns changing due to heavy academic workload. This may have ill effects on their health. Though most factors that affect sleep are modifiable and treatment for them exists still there are can be many factors that affect sleep which should be explored. The thermal model of human body is a theoretical model that accounts for thermal effects of electromagnetic waves on a given point in human body. This could be easily affect brain as it has highest electrical activity in body and may lead to sleep related disorders.Methods: This study is conducted on medical and dental students to analyse the amount of electromagnetic field they get exposed to and any changes in sleep patterns associated with it. The findings of medical and dental students are compared to see if changes in sleep patterns are due to professional course pursued. Any other confounding factors affecting this study are screened by self-rated Pacific Sleep Questionnaire.Results: There were significant changes seen in the time taken to fall asleep and total sleep period but the time taken to wake up from sleep remained unaffected. The sleeping habits of medical and dental students showed no significant changes.Conclusions: Static electromagnetic fields have significant impact on sleep onset and sleep duration. This is regardless of academic background.
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Objective To investigate whether the low-frequency pulsed electromagnetic fields (LF-PEMFs) can enhance the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) induced by bone morphogenetic protein 9 (BMP9). Methods We isolated CD146＋/STRO-1＋ cells (namely PDLSC) from periodontal ligament cells of healthy human premolars, transfected the PDLSC with BMP9-overexpressing recombinant adenoviruses (Ad-GFP-BMP9), exposed the cells to the different intensities of PEMF stimulation (15 Hz, 0.6，1.2，1.8，2.4，3.0 mT, 1 h/12 h), and then detected the expression of runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteopontin (OPN) and osteocalcin (OCN) by qRT-PCR and Western blotting. Results Overexpression of BMP9 significantly promoted the expression of osteogenic markers (Runx2, ALP, OCN and OPN) in PDLSC (P0.05). After the intervention with 1.2, 1.8, 2.4 and 3.0 mT PEMF, the expression levels of osteogenic markers in PDLSC were significantly higher than those exposed to BMP9 alone (P0.05), and reached the peak at 2.4 mT (P0.05), indicating that LF-PEMFs enhanced BMP9-induced osteogenic differentiation of PDLSC, and there was a “window effect”. Conclusion LF-PEMFs stimulation (15 Hz, 1.8 to 3.0 mT) can enhance BMP9-induced osteogenesis of hPDLSCs in vitro.
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Objective@#By modeling ischemic foot ulcers in experimental rabbits, the mechanism of healing in animal models was investigated.@*Methods@#Sixty healthy male clean grade New Zealand rabbits were 3 months. The weight range was 2.1-2.5 kg. Randomly draw auording to the number, the experimental rabbits were randomly divided into 4 groups, namely, no ischemia-no ulcer-no intervention group (group A), no ischemia-no ulcer-no intervention group (group B), no ischemia-no ulcer-no intervention group (group C) and no ischemia-ulcer-intervention group (group D), with 15 rabbits in each group. Ischemic foot ulcers experimental rabbit building complete after 24 h, will naturally exposed ischemic foot ulcers in the low frequency electromagnetic field on experimental rabbit 7 d feeding experiment, the experimental rabbits ischemia crus muscle and the ulcer base were collected, and plasma by enzyme-linked immunosorbent assay (ELISA) verification tests in experimental rabbit plasma hypoxia-inducible factor 1 alpha subunit (HIF-1α), matrix metalloproteinases 9 (MMP-9) and soluble leukocyte differentiation antigen 40 ligand 1 (sCD40L1) expression level, while detecting ulcer healing area change, hematoxylin-eosin staining was used to detect and analyzed the pathological changes of ulcerated skin. Measurement data were expressed as mean±standard deviation (Mean±SD), one-way analysis of variance was used for comparison between groups, and LSD method was used for pairwise comparison.@*Results@#The concentration of MMP-9 and sCD40L1 in group D were (40.510±10.155) ng/ml and (44.580±19.138) ng/ml, respectively. Concentrations in group C were (93.210±17.838) ng/ml and (318.500±52.680) ng/ml, respectively. Group D was significantly lower than group C, and the difference was statistically significant (P< 0.000 1). The concentrations of HIF-1α in group D was (249.700±71.824) ng/ml, and that in group C was (124.830±20.110) ng/ml. The concentration in group D was significantly higher than that in group C, and the difference was statistically significant (P< 0.000 1). The concentrations of HIF-1α, MMP-9 and sCD40L1 in group B were (181.590±31.927), (78.950±16.652) and (173.670±43.048) ng/ml, respectively. The concentrations of group A were (35.420±9.916), (32.700±6.449) and (47.440±11.831) ng/ml, respectively. The concentration in group B was significantly higher than that in group A, the difference was statistically significant(P<0.000 1). The concentration of HIF-1α in group D was (249.700±71.824) ng/ml, and the concentration of group A was (35.420±9.916) ng/ml. The concentration of group D was significantly higher than that of group A, and the difference was statistically significant (P=0.000 1). The concentration of the MMP-9 in the group D was compared with the concentration of group A, and the difference was not statistically significant (P=0.207). The concentration of sCD40L1 in group D was (44.580±19.138) ng/ml, and that in group A was (47.440±11.831) ng/ml. The difference between group D and group A was not statistically significant(P=0.858). The healing area of ulcer was (1.855±0.394) cm2 in group D and (0.653±0.269) cm2 in group C. Group D was significantly higher than group C, and the difference was statistically significant (P<0.000 1). Hematoxylin-eosin staining results of ulcer skin showed that the epithelial of ischemic foot ulcer was significantly atrophied, hyperkeratinized, and the acinous cell layer was atrophied with a small amount of obvious inflammatory cell infiltration and hyperplasia of small vessels. After intervention, the symptoms were relieved.@*Conclusion@#Low frequency electromagnetic fields can promote the expression of HIF-1α in experimental rabbits, inhibit the expression of MMP-9 and sCD40L1, and promote the healing of ischemic foot ulcer.
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Objective@#To explore the expression of the A2A adenosine receptor and the inflammatory cytokines interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in human degenerative nucleus pulposus (NP) cells after they have been treated with a pulsed electromagnetic field (PEMF).@*Methods@#Human degenerative NP cells were cultured in vitro and treated using an 0.8mT PEMF with a pulse frequency of 50Hz. The pulse width was 150μs and the exposure time was 30min, repeated 5 times at 12 hour intervals. The expression of the A2A adenosine receptor in NP cells was determined using western blotting and reverse transcription polymerase chain reactions. The expression of the inflammatory cytokines IL-1β and TNF-α were detected using enzyme-linked immunosorbent assays (ELISA). The human degenerative NP cells were also treated with an antagonist and agonist of the A2A adenosine receptor, and the expression of IL-1β and TNF-α were also determined using ELISA.@*Results@#After the PEMF treatment the expression of the A2A adenosine receptor increased significantly, while the expression of IL-1β and TNF-α decreased significantly. However, the A2A adenosine receptor antagonist reversed the inhibitory effect of the PEMF on the expression of IL-1β and TNF-α, while the agonist played an opposite role.@*Conclusion@#A PEMF can significantly inhibit the expression of IL-1β and TNF-α in human degenerative NP cells, which could be related to up-regulation of the expression of the A2A adenosine receptor in those cells.
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Objective@#To investigate the signal transduction mechanisms of time-dependent effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields(SEMFs)on osteoblastic activity.@*Methods@#Newborn rat calvarial osteoblasts(ROBs)were treated with 50 Hz 1.8mT SEMFs for 30, 60, 90, 120, and 150 min, respectively.Intracellular alkaline phosphatase(ALP)activity was assayed, and protein expression of Runt-related transcription factor 2(Runx2), Smad1/5/8 and mitogen-activated protein kinases(MAPKs)were examined by Western blot.The Dual-Luciferase Reporter Assay System was used to measure the activity of the Wnt pathway.Immunofluorescence staining and laser confocal microscopy were applied to examine the nuclear translocation of Smad1/5/8 and β-catenin.Changes in ALP activity were determined after inhibiting p38 MAPK using a specific inhibitor.@*Results@#ALP activity of ROBs increased after 30, 60, 90, 120 and 150 min of SEMFs treatment, compared with the control group(51.41±5.21, 59.47±4.02, 67.56±4.68, 63.69±3.92, and 58.16±3.61 vs.45.53±3.24), and reached the highest value at 90 min and then started to decline.Protein expression of Runx-2, p-Smad1/5/8, p-p38 and β-catenin increased after SEMFs treatment, and reached the highest value at 90 min and then gradually returned to baseline levels.The values for Wnt pathway activity for the control group and with SEMFs treatment at 30, 60, 90, 120 and 150 min were 0.49±0.06, 0.52±0.09, 0.75±0.05, 0.77±0.42, 0.58±0.08 and 0.42±0.09, respectively.Wnt pathway activity, the nuclear translocation of β-catenin and Smad1/5/8 reached the highest level at 90 min.Values of ALP activity in the control group and the SEMFs group were 44.60±3.84 and 71.54±7.34, respectively, before specifically inhibiting p38 MAPK, and were 52.08±0.83 and 52.15±10.77, respectively, after p38 MAPK inhibition, indicating that ALP activity could not be increased with inhibition.@*Conclusions@#50 Hz 1.8 mT SEMFs increase osteoblastic activity by activating the BMP-2/Smad1/5/8, Wnt/β-catenin and p38 MAPK signal pathways.The optimal duration of treatment is 90 min per day.
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Objective To investigate the signal transduction mechanisms of time-dependent effects of 50 Hz 1.8 mT sinusoidal electromagnetic fields(SEMFs)on osteoblastic activity.Methods Newborn rat calvarial osteoblasts(ROBs) were treated with 50 Hz 1.8mT SEMFs for 30,60,90,120,and 150 min,respectively.Intracellular alkaline phosphatase (ALP) activity was assayed,and protein expression of Runt-related transcription factor 2 (Runx2),Smad1/5/8 and mitogen-activated protein kinases(MAPKs)were examined by Western blot.The Dual-Luciferase Reporter Assay System was used to measure the activity of the Wnt pathway.Immunofluorescence staining and laser confocal microscopy were applied to examine the nuclear translocation of Smad1/5/8 and β-catenin.Changes in ALP activity were determined after inhibiting p38 MAPK using a specific inhibitor.Results ALP activity of ROBs increased after 30,60,90,120 and 150 min of SEMFs treatment,compared with the control group(51.41±5.21,59.47±4.02,67.56[4.68,63.69±3.92,and 58.16±3.61 vs.45.53± 3.24),and reached the highest value at 90 min and then started to decline.Protein expression of Runx-2,p-Smad1/5/8,p-p38 and β-catenin increased after SEMFs treatment,and reached the highest value at 90 min and then gradually returned to baseline levels.The values for Wnt pathway activity for the control group and with SEMFs treatment at 30,60,90,120 and 150 min were 0.49± 0.06,0.52 ± 0.09,0.75±0.05,0.77 ± 0.42,0.58 ± 0.08 and 0.42 ± 0.09,respectively.Wnt pathway activity,the nuclear translocation of β-catenin and Smad1/5/8 reached the highest level at 90 min.Values of ALP activity in the control group and the SEMFs group were 44.60±3.84 and 71.54±7.34,respectively,before specifically inhibiting p38 MAPK,and were 52.08±0.83 and 52.15±10.77,respectively,after p38 MAPK inhibition,indicating that ALP activity could not be increased with inhibition.Conclusions 50 Hz 1.8 mT SEMFs increase osteoblastic activity by activating the BMP-2/Smad1/5/8,Wnt/β-catenin and p38 MAPK signal pathways.The optimal duration of treatment is 90 min per day.
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Objective By modeling ischemic foot ulcers in experimental rabbits,the mechanism of healing in animal models was investigated.Methods Sixty healthy male clean grade New Zealand rabbits were 3 months.The weight range was 2.1-2.5 kg.Randomly draw auording to the number,the experimental rabbits were randomly divided into 4 groups,namely,no ischemia-no ulcer-no intervention group (group A),no ischemia-no ulcer-no intervention group (group B),no ischemia-no ulcer-no intervention group (group C) and no ischemia-ulcerintervention group (group D),with 15 rabbits in each group.Ischemic foot ulcers experimental rabbit building complete after 24 h,will naturally exposed ischemic foot ulcers in the low frequency electromagnetic field on experimental rabbit 7 d feeding experiment,the experimental rabbits ischemia crus muscle and the ulcer base were collected,and plasma by enzyme-linked immunosorbent assay (ELISA) verification tests in experimental rabbit plasma hypoxia-inducible factor 1 alpha subunit (HIF-1 α),matrix metalloproteinases 9 (MMP-9) and soluble leukocyte differentiation antigen 40 ligand 1 (sCD40L1) expression level,while detecting ulcer healing area change,hematoxylin-eosin staining was used to detect and analyzed the pathological changes of ulcerated skin.Measurement data were expressed as mean ± standard deviation (Mean ± SD),one-way analysis of variance was used for comparison between groups,and LSD method was used for pairwise comparison.Results The concentration of MMP-9 and sCD40L1 in group D were (40.510 ± 10.155) ng/ml and (44.580 ± 19.138) ng/ml,respectively.Concentrations in group C were (93.210 ± 17.838) ng/ml and (318.500 ± 52.680) ng/ml,respectively.Group D was significantly lower than group C,and the difference was statistically significant (P ＜ 0.000 1).The concentrations of HIF-1α in group D was (249.700 ±71.824) ng/ml,and that in group C was (124.830 ±20.110) ng/ml.The concentration in group D was significantly higher than that in group C,and the difference was statistically significant (P ＜ 0.000 1).The concentrations of HIF-1αt,MMP-9 and sCD40L1 in group B were (181.590 ± 31.927),(78.950 ± 16.652) and (173.670 ±43.048) ng/ml,respectively.The concentrations of group A were (35.420 ± 9.916),(32.700 ± 6.449) and (47.440± 11.831) ng/ml,respectively.The concentration in group B was significantly higher than that in group A,the difference was statistically significant (P ＜ 0.000 1).The concentration of HIF-1 α in group D was (249.700 ± 71.824) ng/ml,and the concentration of group A was (35.420 ±9.916) ng/ml.The concentration of group D was significantly higher than that of group A,and the difference was statistically significant (P =0.000 1).The concentration of the MMP-9 in the group D was compared with the concentration of group A,and the difference was not statistically significant (P =0.207).The concentration of sCD40L1 in group D was (44.580 ± 19.138) ng/ml,and that in group A was (47.440 ± 11.831) ng/ml.The difference between group D and group A was not statistically significant(P =0.858).The healing area of ulcer was (1.855 ±0.394) cm2 in group D and (0.653 ± 0.269) cm2 in group C.Group D was significantly higher than group C,and the difference was statistically significant (P ＜ 0.000 1).Hematoxylin-eosin staining results of ulcer skin showed that the epithelial of ischemic foot ulcer was significantly atrophied,hyperkeratinized,and the acinous cell layer was atrophied with a small amount of obvious inflammatory cell infiltration and hyperplasia of small vessels.After intervention,the symptoms were relieved.Conclusion Low frequency electromagnetic fields can promote the expression of HIF-1α in experimental rabbits,inhibit the expression of MMP-9 and sCD40L1,and promote the healing of ischemic foot ulcer.
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Introducción: Las radiaciones no ionizantes no poseen el nivel de energía requerido para producir ionización en los tejidos o causar daño al DNA, pero pueden generar efectos térmicos y no térmicos en la salud de los seres humanos que son actualmente motivo de estudio y discusión. Gran parte de la actividad cotidiana en ámbitos académicos se desarrolla bajo la influencia de innumerables radiaciones. Objetivo: Evaluar y determinar el nivel de exposición a las radiaciones no ionizantes en ámbitos académicos de la Universidad Nacional de La Plata, Argentina. Metodología: Las mediciones fueron realizadas mediante el instrumento marca Narda® NBM 550 con sonda de medición isotrópica en la banda de 100 kHz a 3 GHz. Se realizaron mediciones exteriores (outdoor) en diferentes facultades de la Universidad Nacional de La Plata. En la facultad de Ciencias Médicas se efectuaron mediciones interiores (indoor). En esta última se seleccionaron tres ambientes para determinar las principales fuentes de emisión. Resultados: Los valores máximos obtenidos de las mediciones se encontraron por debajo del valor máximo permitido de 0,2 mW/cm2. En la facultad de Ciencias Médicas se realizaron mediciones específicas en dos lugares de alto tránsito y uno de varias horas de permanencia en el lugar de exposición. El procesamiento de los datos reveló que las mediciones específicas a 20 cm de los artefactos eléctricos de iluminación fueron superiores al máximo permitido. Discusión: Si bien los resultados de las mediciones exteriores realizadas en los diversos ámbitos académicos se encuentran dentro de los valores permitidos, es recomendable que las mediciones se efectúen en forma anual, además de instalar fuentes de bajas emisiones
Introduction: Non-ionizing radiation does not have the level of energy required to produce ionization in tissues or cause DNA damage, but can generate thermal and non-thermal effects on human health that are currently the subject of study and discussion. Much of the daily activity in academic areas is performed under the influence of innumerable radiations. Objective: Evaluate the exposure levels to non-ionizing radiation in academic and sensitive areas in different faculties of the National University of La Plata, Argentina. Methodology: The measurements were made using the Narda® NBM 550 instrument with an isotropic measurement probe in the 100 kHz band at 3 GHz. Seven exterior measurements were taken (outdoor) in different Faculties: In the Faculty of Medical Sciences internal (indoor) measurements were made. Of the latter, three environments were selected to determine the main sources of emission. Results: The maximum values obtained from the external and internal measurements were found below the maximum value of 0.2 mW / cm2. At the Faculty of Medical Sciences, specific measurements were made on two sites of high circulation and on one of several hours of permanence at the place of exposure. Data processing revealed that the specific measurements at 20 cm of the electric lighting fixtures were higher than the maximum allowed. Discussion: It can be inferred that although the results of the external measurements made in the different academic fields are within the allowed values, it is recommended that the measurements be made annually and the use of low emission sources
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Oective: To discuss the effects of extremely low frequency electromagnetic fields (ELF-EMF) exposure on the function and morphology of liver, kidney and spleen of the SD rats, and to clarify the mechanism of radiation damage of ELF-EMF. Methods: Twenty male SD rats were randomly divided into exposure group and control group (n=10). The rats in exposure group were exposed in an ELF-EMF device with a magnetic induction of 0. IT and a frequency of 50 Hz; the exposure was conducted for 8 h per day for 30 d. The rats in control group didn' t receive any treatment. After exposure for 30 d, the serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (UN), creatinine (Cr) of the rats in two groups were detected. HE staining was used to detect the morphology of the liver, kidney, spleen tissues of the rats in two groups. Results: Compared with control group, the serum levels of ALT, AST, UN, and Cr of the rats in exposure group were increased (P<0. 05). In exposure group, the dilatation and congestion were found in the central veios of liver and hepatic sinusoids, glomeruli and interstitial capillaries of kidney, and insinusoids of spleen of the rats; part of the hepatocytes showed necrosis. There was no abnormality morphology in the liver, kidney, and spleen tissues of the rats in control group. Conclusion: Exposure to ELF-EMF (0.1 T, 50 Hz) can affect the function and structures of liver, kidney and spleen tissues of the SD rats, and its mechanism may be related to oxidative stress induced by ELF-EMF.
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Objective To investigate the effect of a pulsed electromagnetic field ( PEMFS) on bone mineral density and bone metabolism in males with osteoporosis after a stroke. Methods Fifty male stroke survivors with os-teoporosis were randomly divided into a control group and a treatment group, both of 25. Both groups were treated with routine rehabilitation, oral calcium carbonate and vitamin D3 tablets, while the treatment group was additionally pro-vided with PEMFS treatment. The subjects′bone mineral density ( BMD) and their blood levels of bone-specific alka-line phosphatase (B-ALP), type I procollagen amino-terminal peptide (PINP) and type β-I collagen cross-linked carboxy-terminal peptide (β-CTx) were measured before and after the 12 weeks of treatment. Results After the treatment the BMD values of the lumbar spine, femoral neck, trochanter and Ward′s triangle had increased signifi-cantly in both groups, but the average BMD values of the lumbar spine and femoral neck in the treatment group were significantly higher than those of the control group. After the treatment, the average B-ALP, PINP andβ-CTx levels of both groups had also improved significantly compared with before the treatment, but the average improvement in all three among the treatment group was significantly greater than among the controls. Conclusion PEMFS treatment supplementing routine rehabilitation, oral calcium carbonate and vitamin D3 tablets can improve bone formation, re-duce bone resorption and increase bone mineral density in men after a stroke.
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Objective To observe the effect of a pulsed electromagnetic field (PEMF) on the bone structure and metabolism of rats with disuse osteoporosis (DOP).Methods One hundred 4-month-old female Sprague-Dawley rats were randomly divided into a control group (INT group),an osteoporosis model group (DOP group),a sodium alendronate group (ALN group) and a pulsed electromagnetic field group (PEMF group),each of 25.The right hind-limbs of the rats in the DOP,ALN and PEMF groups were immobilized by tibia-tail fixation for two weeks to establish a DOP model.The rats in the ALN group were given 1 mg/kg of sodium alendronate once a day,while those in the PEMF group received PEMF at 3.82 mT and 10 Hz with a pulse time of 8 ms for 40 min/d.Five rats in each group were sacrificed at the 2nd,4th,8th and 12th week and their right hind-limbs were separated to measure the bone mineral density (BMD),structural mechanics indexes (the maximum load,maximum displacement and rupture energy) and material mechanics indexes (maximum stress,maximum strain and modulus).Moreover,the expression of tumor necrosis factor alpha (TNF-α) and bone morphogenetic protein 2 (BMP-2) were detected using immunohistochemical methods.Results The average BMD of the model group was significantly lower than that of the ALN group after 2 weeks,and lower than that of the PEMF group after 4 and 8 weeks.After 12 weeks the average BMD of the PEMF group was significantly higher than that of the ALN and model groups.After two and four weeks,all the structural and material mechanics measurements had decreased significantly compared with those of the control group.The average maximum displacement and load of the ALN group had increased significantly compared with the model group after 4 weeks of treatment.After 8 weeks the average maximum load,maximum displacement,rupture energy and maximum stress of the ALN and PEMF groups had increased significantly compared with the model group.Compared with the model group,the average level of TNF-α decreased gradually in both the ALN and PEMF groups from the 2nd week on,while that of BMP-2 increased from the same time point.However,at the 8th week the expression of BMP-2 protein in the PEMF group was on average significantly higher than in the ALN group.Conclusion Both PEMF and sodium alendronate can increase bone density,but PEMF has more persistent effects.
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This study was conducted to evaluate the effect of argan oil with the exposure of low frequency electromagnetic field (EMF)on open wound healing in mice. Eighteen male mice (20-40 g) were divided into three groups: phosphate buffer saline(PBS) as negative control, solcoseryl gel as positive control, and argan oil with the exposure of low frequency EMF, 1.2mT (treatment group). Full thickness wounds (4 mm diameter) were induced on the shaved dorsal of the mouse. All micewere sacrificed on day 12 after the final treatment. Macroscopic observation, wound contraction rate, histopathologyanalysis and total protein content were examined in this study. Results showed that wounds treated with argan oil andexposed to low frequency EMF has a significant increase in wound contraction rate (p < 0.05) and total protein content(p < 0.05). Moreover, histopathological analysis on the wound tissues displayed complete re-epithelization with thick anddense collagen fibers in the argan oil with low frequency EMF exposure treated group. In conclusion, topical treatment ofargan oil with low frequency EMF exposure yield a better healing progress and showed the ability to accelerate woundhealing.
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Aim: The objective of this study was to measure and compare the in vitro performance of active and passive self-ligating brackets in orthodontic rotation by means of an electromagneticfield simulation. Methods: The study sample consisted of 32 mandibular right central incisor brackets (n=8), slot 0.022", that were divided into the following groups: 1) BioQuick® (Forestadent, Pforzheim, Germany) active brackets; 2) In- Ovation®R (Dentsply-GAC, Central Islip, New York, USA) active brackets; 3) Damon-Q® (Ormco, Orange, California, USA) passive brackets, and 4) Smartclip® (3M, Monrovia, California, USA) passive brackets. The orthodontic wire used was CuNiTi round section 0.016", thermoactivated at 35o C (ORMCO- Orthodontics Glendora, California, USA). The experiment wasperformed in a simulator machine, composed of two fixedlateral axes and a movable central axis, which simulated the dental rotation. Qualitative analysis (n = 4) was performed using SEM. After the descriptive and exploratory analysis, the yield and grade data were submitted to one-way analysis of variance (ANOVA) followed by the Tukey test, considering the level ofsignificance of 5%. Results: In-Ovation®R brackets showedsignificantly higher yield than BioQuick® and Damon-Q®. Damon-Q® brackets presented a significantly lower mean valuethan In-Ovation R and Smartclip®. BioQuick® did not differsignificantly from Damon-Q® and Smartclip®. In-Ovation®R did not differ significantly from Smartclip®. Conclusion: In the present study, it was observed that there is a difference in rotational control in the different self-ligating brackets tested being the best rotational control was the In-Ovation R® group (active), followed in descending order by the groups Smartclip® (passive), Bioquick® (active) and Damon Q® (passive)
Subject(s)
Rotation , Orthodontic Brackets , Electromagnetic FieldsABSTRACT
Fundamento: en todas las áreas de la vida moderna, está presente de forma creciente la exposición a campos electromagnéticos de frecuencia muy baja, su influencia sobre la salud de los seres humanos constituye un tema de debate a nivel mundial por considerarse como posibles carcinógenos humanos. Objetivo: realizar un análisis crítico del tema basado en los valores de exposición a los campos electromagnéticos de frecuencia baja, propuestos en las directrices de la comisión internacional para la protección contra las radiaciones no ionizantes y la bibliografía existente consultada. Métodos: se realizó una revisión bibliográfica con el método de análisis bibliográfico a través de una búsqueda realizada entre los años 1979 al 2016, donde se consultaron bases de datos especializadas y se seleccionaron 28 publicaciones científicas sobre el tema. Desarrollo: la comisión internacional para la protección contra las radiaciones no ionizantes publicó directrices de exposición en 1998 y 2010, de manera que superó por margen muy amplio los valores de la segunda respecto a la primera, lo que no se justifica de acuerdo a los numerosos estudios publicados sobre el tema que relacionan la aparición de leucemia con inducciones magnéticas mayores de 0,4 µT. Conclusiones: los sistemas biológicos sufren la influencia de la inducción magnética de los campos electromagnéticos de frecuencia muy baja antropogénicos. Existe la necesidad de que la proyección mundial sobre este tema esté dirigida a la protección inmediata de las personas con regulaciones sanitarias de carácter legal.
Background: in all areas of modern life, exposure to extremely low frequency electromagnetic fields is increasingly present, its influence on human health continues to be a subject of worldwide debate by considered as possible human carcinogens. Objective: this led to a critical analysis of the topic based on exposure values to extremely low frequency electromagnetic fields, proposed in the guidelines of the International Commission on Non-ionizing Radiation Protection and the existing bibliography consulted. Methods: a bibliographic review was carried out using the method of bibliographic analysis through a search carried out between 1979 and 2016, where specialized databases were consulted and 28 scientific publications were selected on the subject. Development: the International commission on non-ionizing radiation protection published exposure guidelines in 1998 and 2010, surpassing the values of the second with respect to the first, which is not justified according to the numerous published studies on the subject that relate the occurrence of leukemia with magnetic inductions greater than 0.4 µT. Conclusions: biological systems are influenced by the magnetic induction of anthropogenic extremely low frequency electromagnetic fields. There is a need for the global projection on this issue to be directed at the immediate protection of persons with legal health regulations.