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Silicosis is one of the most common forms of pneumoconiosis globally. Workers who engage in mining, construction, ceramics, and many other industries have a high risk of developing silicosis. Chronic and repeated inhalation of free silica (SiO2) dust (<5 μm) during working can lead to inflammatory reactions, resulting in interstitial lung disease characterized by extensive nodular fibrosis in both lungs. Once silicosis occurs, it will develop progressively even when the workers are removed from the silica dust environment. The pathogenesis of silicosis is complex, especially the role of nod-like receptor family protein 3 (NLRP3) inflammasome in the pathogenesis and progression of silicosis remains to be further studied. NLRP3 inflammasome, a multi-protein complex composed of NLRP3, apoptosis-associated speck-like protein, and cysteinyl aspartate specific proteinase 1 is involved in oxidative stress, inflammatory response, apoptosis, and pyroptosis, and has become one of the hot spots in silicosis research. This review summarized the structure, function, and activation mechanism of NLRP3 inflammasome. Furthermore, the cellular and molecular mechanisms of NLRP3 in mediating oxidative stress, inflammatory response, apoptosis, and pyroptosis in the progression of silicosis were reviewed. Finally, the potential therapeutic drugs for silicosis based on NLRP3-associated mechanisms were outlined. More attention should be paid to the role of NLRP3 inflammasome in the pathogenesis and progression of silicosis in the future, which will provide new ideas for the prevention and treatment of silicosis.
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Objective To investigate the establishment of focal cerebral ischemia model in rabbits with the improved suture method.Methods A total of 45 healthy and clean adult New Zealand rabbits were divided into either a sham operation group (n =5) or a model group (n =40) using random number table method before modeling,and the sex was not limited.The self-made head ends of 2-0 fishing lines dipped in paraffin were used as the sutures.The external carotid artery was cut and inserted into a intracranial artery through the internal carotid artery and blocked the origin of middle cerebral artery.The neurological function score was performed after 6 h.The neurological deficit scores ≥2 was successful modeling.The rabbits were killed by anesthesia.The brain slices were stained with 2％ 2,3,5-triphenyl tetrazolium chloride solution.The infarct foci were observed.The diameters of suture head and the depth of suture insertion were compared in the model rabbits with successful modeling,failure,and death in the model group.Results There were 40 rabbits in the model group,six of them died,including 4 died of subarachnoid hemorrhage within 4 h after operation,and 2 died from anesthetic accident.The mortality rate was 15.0％.Seven rabbits failed,mainly because of cerebral vasospasm and the insertion depth of suture was insufficient.Twenty-seven had successful modeling,and the success rate was 67.5％.All the rabbits in the sham operation group survived.The diameter of the suture head and insertion depth in the successful modeling rabbits were compared with the death and failure outcome in rabbits.The difference was statistically significant (diameter:0.52 ± 0.14 mm vs.0.45 ±0.40 mm and 0.58 ±0.17 mm;depth:5.49 ±0.17 cm vs.6.04 ± 0.11 cm and 4.26 ±0.30 cm;all P ＜ 0.05).Conclusions The improved suture method can successfully prepare the focal cerebral ischemia model of middle cerebral artery in rabbits.The method is simple.Its repeatability and practicability are better.
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Objective To investigate the biomechanical and pathological changes in vivo in the taut bands (TB) of biceps femoris in rats after repeated low-frequency electrical stimulation.Methods Twenty-eight Wistar rats were randomly divided into a control group,an electrical intensity-dependent fatigue group,which were subject to electric intensity-dependent fatigue test,and an electrical frequency-dependent fatigue group,which were subject to electrical frequency-dependent fatigue test.After fatigue tests,the taut band of the biceps femoris and the non-taut band of the contralateral biceps femoris were harvested for pathological observation.The maximum contraction force (MCF),electrical intensity-and frequency-dependent fatigue characteristics and any pathological changes in the TBs were assessed and compared to the non-taut band region of the other biceps femoris.Results The MCF at the 15th and 20th stimulation (1.42 ± 0.28 g and 0.93 ± 0.54 g respectively) were significantly lower than that at the 1 st and 5th stimulation of the TBs.High stimulation intensity (HSI) at the 15th and 20th stimulation (3.76 ± 0.71 V and 3.44 ± 0.97 V) were also significantly lower than at the 1st TB stimulation.At the 10th,15th and 20th stimulation of the TBs,MCF and HSI were both significantly lower than in the bands which were not tight.In the frequency-dependent fatigue stimulation tests,the frequency which generated the MCF of the TBs was significantly lower than in the bands which were not tight,while the MCF of the TBs was significantly higher than that of non-TBs.After either intensity or frequency fatigue testing,more severe edema,uneven cytoplasmic death and degeneration of muscle fibers were observed in sections from TBs than from the bands which were not tight.Conclusions Taut muscle bands are significantly less fatigue-resistant than normal muscle fibers.Taut bands may contribute to the fatigue of myofascial pain syndromes.
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Objective To investigate the effects of hyperbaric Oxygen (HBO)exposure on Caspase-3 and Bcl-2 mRNA ex-pressions in both internal carotid artery (ICA)and basal artery (BA)in rabbits.Methods Twenty-four healthy adult New Zealand rabbits were randomly divided into 2 groups:HBO group and the control group,with each group consisted of 12 animals.The rab-bits in the HBO group were exposed to HBO at 2.2 ATA for 60 minutes each day for 3 successive days.The rabbits in the control group were normally fed without any treatment.Real-time PCR was used to detect Caspase-3 and Bcl-2 mRNA expressions in both ICA and BA in 2 groups.Results HBO significantly decreased the Caspase-3 mRNA expression [(0.038 ±0.006 )vs .(1.000 ± 0.225)]and increased the Bcl-2 mRNA expression [(1.877 ±0.1 69)vs .(1.000 ±0.364)].In ICA,HBO similarly decreased the Caspase-3 mRNA expression [(0.41 9±0.091)vs .(1.000 ±0.1 75)]and increased the Bcl-2 mRNA expression [(1.269 ±0.270) vs .(1.000±0.1 1 7)]in BA.All the differences mentioned above were of statistical significance (P <0.01).Conclusion HBO ex-erts an inhibition effect on apoptosis in cerebral vascular endothelial cells.The mechanism may be related to inhibiting the expres-sion of Caspase-3 mRNA and promoting the expression of Bcl-2 mRNA.