Effectiveness and prognostic factors of different minimally invasive surgeries for vertebral compression fractures.

BACKGROUND: The aging of China's population has led to an increase in the incidence rate of osteoporosis, which indirectly increases the risk of OVCF in osteoporosis patients. Low back pain is the main symptom of OVCF, and severe patients can further develop kyphosis. Although the conservative treatment of OVCF can effectively control the patient's condition, long-term bed rest will increase the risk of OVCF complications. Minimally invasive surgery is a common solution for OVCF. METHODS: 100 OVCF patients admitted to our hospital from January 2021 to January 2022 are selected for analysis and randomly divided into PVP group and PKP group, 50 cases in each group. The PVP group and the PKP group undergo PVP and PKP operations respectively. The differences in efficacy indicators and adverse reactions are compared, and the multivariate Logistic regression method is used to analyze the influencing factors of postoperative secondary fractures in patients with vertebral compression fractures. RESULTS: Compared with the PVP group, the total effective rate of PKP group is significantly increased, and the VAS, ODI score, kyphotic Cobb Angle, lateral distribution rate of bone cement and bone cement leakage rate are significantly decreased (P < 0.05). Age ≥ 80 years old, female, glucocorticoid use, lateral distribution of bone cement and bone cement leakage are significantly higher in the proportion of secondary fractures and are independent risk factors for postoperative secondary fractures in patients with OVCF. CONCLUSION: PKP surgery has a higher efficacy in the treatment of OVCF patients, which can reduce the incidence of pain, adverse reactions and promote the recovery of kyphotic Cobb Angle. PKP surgery has a higher value in the treatment of OVCF. In addition, the influencing factors of secondary fracture after minimally invasive surgery in OVCF patients include age, gender, glucocorticoid use, bone cement distribution pattern, bone cement leakage, etc.

Pyrethroid Carboxylesterase PytH from Sphingobium faniae JZ-2: Structure and Catalytic Mechanism.

Carboxylesterase PytH, isolated from the pyrethroid-degrading bacterium Sphingobium faniae JZ-2, could rapidly hydrolyze the ester bond of a wide range of pyrethroid pesticides, including permethrin, fenpropathrin, cypermethrin, fenvalerate, deltamethrin, cyhalothrin, and bifenthrin. To elucidate the catalytic mechanism of PytH, we report here the crystal structures of PytH with bifenthrin (BIF) and phenylmethylsulfonyl fluoride (PMSF) and two PytH mutants. Though PytH shares low sequence identity with reported α/ß-hydrolase fold proteins, the typical triad catalytic center with Ser-His-Asp triad (Ser78, His230, and Asp202) is present and vital for the hydrolase activity. However, no contact was found between Ser78 and His230 in the structures we solved, which may be due to the fact that the PytH structures we determined are in their inactive or low-activity forms. The structure of PytH is composed of a core domain and a lid domain; some hydrophobic amino acid residues surrounding the substrate from both domains form a deeper and wider hydrophobic pocket than its homologous structures. This indicates that the larger hydrophobic pocket makes PytH fit for its larger substrate binding; both lid and core domains are involved in substrate binding, and the lid domain-induced core domain movement may make the active center correctly positioned with substrates.IMPORTANCE Pyrethroid pesticides are widely applied in agriculture and household; however, extensive use of these pesticides also causes serious environmental and health problems. The hydrolysis of pyrethroids by carboxylesterases is the major pathway of microbial degradation of pyrethroids, but the structure of carboxylesterases and its catalytic mechanism are still unknown. Carboxylesterase PytH from Sphingobium faniae JZ-2 could effectively hydrolyze a wide range of pyrethroid pesticides. The crystal structures of PytH are solved in this study. This showed that PytH belongs to the α/ß-hydrolase fold proteins with typical catalytic Ser-His-Asp triad, though PytH has a low sequence identity (about 20%) with them. The special large hydrophobic binding pocket enabled PytH to bind bigger pyrethroid family substrates. Our structures shed light on the substrate selectivity and the future application of PytH and deepen our understanding of α/ß-hydrolase members.