ABSTRACT
BACKGROUND:Temporomandibular joint osteoarthritis can cause severe pain,which significantly affects the patient's quality of life and psychological health.Studies have found that medical ozone can effectively alleviate pain due to temporomandibular joint osteoarthritis,but its analgesic effect and mechanism are still unclear. OBJECTIVE:To explore the effects of medical ozone on pain relief in temporomandibular joint osteoarthritis and the potential mechanisms. METHODS:Twenty-four Sprague-Dawley rats were randomly divided into four groups(n=6 per group):control group,model group,air group,and medical ozone group.A sodium iodate-induced rat model of temporomandibular joint osteoarthritis was established in all groups except for the control group.After 1 week of modeling,rats in the air group and medical ozone group were injected with clean air and medical ozone,respectively,in the temporomandibular joint.The injection frequency for the air group and medical ozone group was once a week for three times in total.The von Frey mechanized pain measurement technique was used to assess the mechanical pain threshold of the temporomandibular joint in rats before and 28 days after modeling.ELISA was utilized to detect interleukin-1β in both serum and temporomandibular joint fluid at 28 days after modeling.Histopathologic changes of the temporomandibular joint were evaluated through hematoxylin-eosin staining.Additionally,the expression levels of hypoxia-inducible factor 1α and cyclooxygenase 2 in the temporomandibular joint were analyzed using immunohistochemistry. RESULTS AND CONCLUSION:Compared with the control group,the mechanical pain thresholds of the temporomandibular joint in the model group were decreased at 1,3,7,14,21,and 28 days after modeling(P<0.01);and compared with the model and air groups,the mechanical pain thresholds of the temporomandibular joint in the medical ozone group were increased at 28 days after modeling(P<0.01).Compared with the control group,the level of interleukin 1β in the serum and joint fluid of rats in the model group was elevated(P<0.01);compared with the model and air groups,the level of interleukin 1β in the serum and joint fluid of rats in the medical ozone group was decreased(P<0.01).Hematoxylin-eosin staining results showed derangement and degeneration of the cartilage structure in the model group and the air group,while the derangement of the cartilage structure in the medical ozone group was less than that in the model group and the air group.Immunohistochemical staining showed that the expression of hypoxia-inducible factor 1α and cyclooxygenase 2 in the temporomandibular joints of rats in the model group was elevated compared with that in the control group(P<0.01);the expression of hypoxia-inducible factor 1α and cyclooxygenase 2 in the temporomandibular joints of rats in the medical ozone group was decreased compared with that in the model group and the air group(P<0.01,P<0.05).These findings suggest that medical ozone can alleviate the pain caused by osteoarthritis of the temporomandibular joints in Sprague-Dawley rats by reducing the expression of hypoxia-inducible factor 1α,interleukin 1β,and cyclooxygenase 2.
ABSTRACT
A 8-channel neural signal′s simultaneous transducer detection micro system was developed to research the neural loop located at the brain hippocampus zone. The components of the system contained the neural probe manufactured with the Micro-electro-mechanical-systems (MEMS) technique based on silicon-on-insulator (SOI) substrate, biological low noise chopper-stabilization amplifier, low noise and intermediate speed SAR-ADC converter, reduced and low power ASK/FSK modulation radio transmitter. The micro system was applicable with the characters of small volume, interferences free, neural electrophysiology and neurotransmitter simultaneous detection, high sensitivity, high linearity, etc. The electrode resistance was optimized to 35.0 kΩ after depositing nanometer platinum black on the 4 electrophysiological sites on the Pt electrode. With the modification enzyme technique, nanomaterial enzyme membrane (Pt-mPD-GluOx) was directly fixed on the glutamate detection locus for selectively detecting special neural neurotransmitter matter. In addition, the electrochemistry measurement results indicated that the linear range of glutamate was 6-35 μmol/L with correlation coefficient of 0.97, the sensitivity was 0.0069 pA/(μmol/L). The current response error was less than 3.0 pA, which showed that the neural needle satisfied differential selection. Also, the logic/analog mixed signal 180-nm Application specific integrated circuit (ASIC ) technique (SmicRF180 nm 1Poly6M) was used to manufacture the transducer back-end disposing IC chip, and the test results provided some key parameters such as chopper-stabilization amplifier (equivalent in putting noise voltage ≤0.7 μV rms@1 kHz, gain of 71-82 dB, CMRR/PSRR>100 dB), SAR-ADC (ENOB is 12 bits, power consumption is 1.2 mW when maxmium conversion speed is 1 Msps, signal-noise-ratio is 60.9 dB, etc), and ASK/FSK modulation radio transmitter (the PA′s outputting power of 4-5 dBm, the radiation range of 10 meters). The micro neural transducer integrated system was convenient and wireless wearable for the research of brain hippocampus region.