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Calcium oxalate crystal is a common cell ergastic substance in plant tissues. Although the mechanism of its synthesis and degradation is not yet clear, it shows a good application prospect in the aspects of calculosis treatment, food safety, plant disease control, pipeline engineering, and saline-alkali utilization. In this review, we discussed the mechanism of synthesis and degradation of calcium oxalate crystals and their physiological functions, and showed the practical application of related research results in urinary stone disease and other fields.
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BACKGROUND: Yaotu Granules have been proved to protect human nucleus pulposus cells and delay their degeneration. Notably, Yaotu Granules for lumbar disc herniation has achieved good clinical results.OBJECTIVE: To investigate the effect of the herbal compound formula Yaotu Granules on the Fas/FasL expression in a rabbit model of lumbar disc degeneration, and further elucidate the underling mechanism of preventing and treating lumbar disc degeneration.METHODS: Twenty New Zealand white rabbits were enrolled and the models of lumbar disc degeneration were established by minimally invasive puncture and rotation cutting, followed by randomized into normal saline, low-, middle-,and high-dose groups (n=5 per group). 10 mL of normal saline, 10, 20, and 40 mL of water decoction of Yaotu Granules were administered intragastrically into the normal saline, low-, middle-, and high-dose drug groups for 21 days, twice daily, respectively. Subsequently, the expression level of Fas/FasL in the rabbit nucleus pulposus cells in each group was detected.RESULTS AND CONCLUSION: The signal intensity of the rabbit lumbar disc on MRI was decreased, and ruptured annulus and posterior herniated disc were visible at 12 weeks after modeling. Masson staining showed that the nucleus pulposus cells arranged in disorder, and even ruptured. Additionally, safranin O staining found that the number of nucleus pulposus cells was decreased obviously. The order of the relative expression levels of Fas and FasL mRNA in the nucleus pulposus cells was as follows: normal saline group > low-dose drug group > middle-dose drug group > high-dose drug group (P < 0.05). These results suggest that Yaotu Granules delay the rabbit lumbar disc degeneration by downregulating the expression level of Fas/FasL.
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<p><b>OBJECTIVE</b>To investigate the stress shielding rate, ultrastructural and biomechanical property of the healing bone fixed by Swan-like Shape Memory Connector (SMC) during experimental fracture healing in rabbits.</p><p><b>METHODS</b>Unilateral osteotomy of left humeral diaphysis was performed in 140 adult New Zealand rabbits. The humeral fracture was fixed with SMC in study group and 4-hole dynamic compression plate (DCP) in control group. The animals were sacrificed at the 2nd, 4th, 8th, 12th, and 16th weeks postoperatively. The humeral shafts were harvested for three-point bending tests and stress shielding rate examination. Samples from the fracture gaps were observed with scanning electron microscope.</p><p><b>RESULTS</b>Within an observation period of 12 weeks after operation, the stress shielding rates were significantly lower in study group than those in control group, and the bending strength and the bending rigidity were statistically higher. It was also found that collagen fibers in callus was arranged more regulate and early mineral deposition in study group.</p><p><b>CONCLUSION</b>These results suggest that SMC contributes to the proliferation and differentiation of osteoblasts, promoting the formation and calcification of bone matrix and enhancing biomechanical property of the healing bone, which might be closely correlated with a less stress shielding effect produced by SMC.</p>