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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 investigate the prevalence and molecular characteristics of Escherichia coli ( E. coli) producing a novel Shiga toxin 2k subtype in goat in Lanling county, Shandong province. Methods:In November 2019, 512 goat fecal samples were collected from different households in Lanling county, Shandong province. After enriched with EC broth, stx-positive samples were detected by PCR and inoculated in CHROMagar? ECC agar and CHROMagar? STEC agar. The whole genomes of stx-positive strains were sequenced. Based on the genomic senquences, the stx subtype, serotype, multi-locus sequence type and virulence genes of each strain were analyzed. Results:Eighty-six strains of Shiga toxin-producing E. coli (STEC) were isolated from 512 goat fecal samples. Five stx subtypes were identified and 37 strains were positive for stx2k. The 86 STEC strains belonged to 20 O∶H serotypes and 18 different sequence types (STs). Conclusions:STEC strains circulating in goats in Lanling county, Shandong province were heterogeneous in stx subtypes, serotypes and virulence gene profiles, and a certain proportion of strains producing a novel Shiga toxin 2k subtype were detected.
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From April 2017 to April 2018, three male patients aged 46-71 years with large area burns were treated in our hospital. Acute acalculous cholecystitis (AAC) symptoms of the patients began to appear 15-81 days after injury. AAC was diagnosed 24-81 days after injury. Ultrasound-guided percutaneous transhepatic cholecystostomy was performed 26-82 days after injury. The symptoms subsided in 2 patients, and cholecystectomy was performed in 1 patient with gallbladder perforation 94 days after injury. The patients were cured and discharged 41-118 days after injury. No recurrence of cholecystitis occurred during 8-9 months of follow-up after discharge.