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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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Objective:To explore the effect of combining pulsed electromagnetic field (PEMF) stimulation with A 2A adenosine receptor agonist CGS-21680 on apoptosis and inflammation of nucleus pulposus cells in cases of intervertebral disc degeneration. Methods:Forty-eight Sprague-Dawley rats were randomly divided into a sham operation group (Sham group), an intervertebral disc degenerative disease group (Model group), an A 2A adenosine receptor agonist CGS-21680 group (Agonist group), and a group in which PEMF was combined with CGS-21680 (Observation group). The rat model of intervertebral disc degeneration (IDD) was established in all other groups than the sham operation group. The rats in the Agonist group were injected with 100μL of CGS-21680 (100μg/kg) at the L 5-6 intervertebral disc. The Observation group was injected with CGS-21680 similarly but then received 14 conse-cutive days of PEMF stimulation (30min/time). The Sham and Model groups were injected with the same amount of normal saline solution. Eight weeks later, HE staining was used to evaluate the pathological changes in the intervertebral disc tissues. The expression of type II collagen was determined by immunohistochemistry. The content and mRNA expression of inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were determined using enzyme-linked immunosorbent assays and reverse transcription-polymerase chain reactions (RT-PCRs). The protein and mRNA levels of A 2A, NLRP3 and caspase-3 were determined by western blotting and RT-PCR. Results:The degeneration in the nucleus pulposus and annulus fibrosus in the Model group was significant, while significantly less shrinkage, necrosis and fibrous annulus rupture was observed in the Observation group. Compared with Model and Agonist groups, the positive expression of Col Ⅱ in the nucleus pulposus, A 2AR protein levels and relative expression of its mRNA had all increased significantly in the Observation group, while the average levels and mRNA expression of pro-inflammatory cytokines IL-6 and TNF-α had decreased significantly. The average protein level and mRNA expression of NLRP3 and caspase-3 in the intervertebral disc tissues of the Observation group were significantly lower than in the Model and Agonist groups. Conclusions:Combining pulsed electromagnetic field stimulation with A 2A adenosine receptor agonist CGS-21680 can inhibit the apoptosis of nucleus pulposus cells, alleviate disease response and delay IDD by up-regulating the activity of A 2A receptors and down-regulating the expressions of pro-inflammatory factors IL-6, TNF-α, NLRP3 and caspase-3 in nucleus pulposus cells.
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Objective:To observe electromagnetic field irradiation′s ability to inhibit heterotopic ossification (HO) and explore the mechanisms involved.Methods:A total of 72 male Sprague-Dawley rats were randomly divided into a control group, a model group and an observation group, each of 24. The rats in the model and observation groups were made to model HO by clamping and cutting the Achilles tendon, while among those in the control group the Achilles tendon was only exposed without clamping and cutting. The rats in the observation group were exposed to a 1mT electromagnetic field alternating sinusoidally at 50Hz (SEMF) twice a day for 2h each time. At 3 days, 14 days, 1 month and 3 months after the operation, Achilles tendon tissue was resected from 6 rats in each group for gross and histological examination and immunohistochemical staining. The protein content and gene expression were detected using western blotting or reverse transcription polymerase chain reaction. X-ray examination was performed at 1 and 3 months after the operation to observe any HO.Results:No significant changes were observed in the control group after the operation. Compared with the model group, HO in the observation group was significantly inhibited. The average expression of the MMP-9 gene in the model and observation groups was significantly higher than in the control group, and it increased with time. The average tissue metalloproteinase-1 (TIMP-1) gene expression was significantly lower, and it decreased with time. Compared with the model group, the average expression of MMP-9 in the observation group was significantly less, while that of TIMP-1 was significantly greater. Compared with the model group, there was also a significant increase in the expression of decapentaplegic homolog 7 (Smad7) protein and a significant decrease in the expression of phosporylated Smad3 protein at each time point.Conclusion:Applying 50Hz, 1mT SEMF has a definite effect in inhibiting HO, at least in rats. It may be related to promoting the expression of Smad7 and inhibiting the phosphorylation of Smad3, thus inhibiting the TGF-β/Smad signal transduction pathway and promoting the restoration of a dynamic balance of MMP-9 with TIMP-1.
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Objective:To analyze the expression level of malignant biological marker gene in locally advanced low rectal cancer tissues after neoadjuvant chemotherapy with XELOX, so as to provide guidance for clinical treatment.Methods:Based on the established inclusion and exclusion criteria, 104 patients with locally advanced low rectal cancer treated in the Surgery Department of the Affiliate Hospital of Qingdao University from January 2017 to January 2018 were included in the study. Based on the random number table method, they were divided into observation group and control group, with 52 patients in each group. Radical resection was performed in both groups, while radical resection was performed directly in the control group, and neoadjuvant chemotherapy with XELOX plus radical resection was performed in the observation group. The effect of tumor resection in the two groups was compared and analyzed, and the expression levels of tumor markers and malignant biological marker genes in the tumor tissues after surgery were determined. The 3-year postoperative survival rate of the two groups was followed up.Results:The R0 resection rate was 96.15% in the observation group and 80.77% in the control group, with statistically significant difference ( P<0.05). There were no significant differences in the serum levels of cancer antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA) and carbohydrate antigen 50 (CA50) before the operation in the two groups ( P>0.05). One week after the operation, the serum levels of CA19-9, CEA and CA50 in the observation group were significantly lower than those in the control group ( P<0.05). Through detection, the relative mRNA expression levels of PPTG and Smad4 in the postoperative observation group were higher than those in the control group, while the relative mRNA expression levels of Runx3 and APC were lower than those in the control group, with statistically significant difference ( P<0.05). The 3-year follow-up survival rate in the observation group was 90.38%, significantly higher than 78.85% in the control group ( P<0.05). Conclusions:The application of XELOX neoadjuvant chemotherapy in radical resection of locally advanced low rectal cancer has important clinical value in reducing tumor malignancy, improving tumor resection effect and improving survival.
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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 effect of ambient temperature on body mass, thermogenic activity and un-coupling protein-1 ( UCP1) content of brown adipose tissue ( BAT) in tree shrews ( Tupaia belangeri) , and to provide the-oretical basis for establishing tree shrews model of obesity.Methods Forty healthy adult tree shrews with similar body mass were uesd in our experiment.The tree shrews were divided into five groups (n=8):control group (0 d), the ani-mals were maintained under 25 ±1℃ and 12L:12D ( light : dark, lights on 08:00) photoperiod; and the animals were maintained under 5 ±1℃and 12L:12D photoperiod for 7 d, 14 d, 21 d and 28 d groups, respectively.At the end of ex-periment, the changes of body mass, nonshivering thermogenesis (NST), BAT mass and uncoupling protein 1 (UCP1) con-tent were determined.Results Compared with the control group (0 d), the body mass, NST, BAT mass and UCP1 con-tent of the cold acclimation groups were improved significantly, the BAT color also obviously deepened, and after cold accli-mation for 28 d, the body mass, NST, BAT mass and UCP1 content were increased by 26.32%, 20.65, 53.85%and 43%, respectively.Apparently, the UCP1 content was significantly positively correlated with BAT mass and NST.Conclusions BAT proliferation may be induced and UCP1 expression upregulated by cold acclimation in Tupaia belangeri, therefore, en-hancing the thermogenic activity of brown adipose tissue to increase energy expenditure.We would speculate that BAT might be used as a target organ for treatment of obesity by energetic approach in the future.
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Objective To evaluate the efficacy of laparoscopic Miles surgery at differented periods.Methods Radical excision(Miles) was performed under a laparoscope on 33 patients from January 2002 to August 2002(group 1),and then on 34 cases from July 2006 to May 2007(group 2) in our hospital.Clinicopathological and follow-up data of the two groups were collected and analyzed.Results No significant difference was found in blood loss(50-200 ml vs 40-210 ml,Z=1.477,P=0.787),number of resected lymph nodes(both 3-5,Z=-0.089,P=0.233),gas expel(in 1-3 days after the surgery vs 1-4 days,Z=-1.622,P=0.574),and postoperative hospital stay(4-9 days vs 5-9 days,Z=-1.834,P=0.346) between the two groups.However,the patients in group 1 had significantly longer operation time and higher medical cost than group 2(175-210 min vs 120-150 min,Z=4.238,P=0.026;23400-27500 yuan vs 19863-22744 yuan,Z=5.283,P=0.003).Conclusion After 4-year development,the operation time and cost of laparoscopic Miles surgery has been decreased.