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Objective To investigate the effect of bone cement distribution on efficacy of vertebroplasty.Methods From January 2013 to June 2016,a total of 132 cases (132 vertebrae) with single segment osteoporotic thoracolumbar vertebral fractures underwent parallel vertebroplasty surgery,and there were 57 male,75 female,with an average age of (71.6±2.2) years old (ranged from 65 to 86 years old).On the basis of the postoperative X-ray films of bone cement distribution were divided into 3 groups.The bone cement was biased to the lateral side of the vertebral body (partial group,35 cases),the bone cement was over the vertebral midline,but not completely filled with contralateral vertebral body (near midline group,46 cases),and the bone cement was filled with bilateral vertebral body (bilateral group,51 cases).There were 15 males and 20 females in the partial group,aged (70.3±5.3) years old;20 males and 26 females in the proximal midline group,aged (72.1±3.2) years old;22 males and 29 females in the bilateral group,aged (71.2±4.6) years old.Local anesthesia was used to make the patient prone to operate on the operating bed.The head and tail of the bed were increased at the same time slightly and vertebral compression fractures reduction was performed.Bone cement was injected into the vertebral body through partial or bilateral transpedicular approach.The visual analogue scores (VAS) were measured of preoperation,postoperation and 3,6,12 months after surgery.Analysis of variance for each group and VAS before and after operation,and postoperative complications were observed too.Results All the 132 cases were followed up for 1-12 months,with an average of (11±0.3) months.There were statistically significant differences in the immediate effect of postoperation among partial group,near middle group and the bilateral group (F=90.472,P=0.000),VAS score in partial group was lower than that in bilateral group (t=11.433,P=0.000),but higher than that in near midline group (t=11.106,P=0.000),and the differences were statistically significant,but there was no significant difference between near midline group and bilateral group (t=0.581,P=0.563).VAS score showed no statistically difference among the three groups 3 months,6 months and 1 year follow-up after operation (F=0.892,P=0.413;F=0.342,P=0.713;F=0.834,P=0.441).In 3 eases of partial group,the pain was not relieved due to unfilled cement until the contralateral bone was injected into the bone cement.However,there were 11 cases of cement leakage in partial group,13 cases in near midline group,and 3 cases in bilateral group.Conclusion The distribution of bone cement is one of the main factors affecting the clinical efficacy after vertebroplasty,and the clinical effect of distributing the midline of vertebral body is better than the one side.
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Homocitrate is a component of the iron-molybdenum cofactor in nitrogenase, where nitrogen fixation occurs. NifV, which encodes homocitrate synthase (HCS), has been identified from various diazotrophs but is not present in most rhizobial species that perform efficient nitrogen fixation only in symbiotic association with legumes. Here we show that the FEN1 gene of a model legume, Lotus japonicus, overcomes the lack of NifV in rhizobia for symbiotic nitrogen fixation. A Fix(-) (non-fixing) plant mutant, fen1, forms morphologically normal but ineffective nodules. The causal gene, FEN1, was shown to encode HCS by its ability to complement a HCS-defective mutant of Saccharomyces cerevisiae. Homocitrate was present abundantly in wild-type nodules but was absent from ineffective fen1 nodules. Inoculation with Mesorhizobium loti carrying FEN1 or Azotobacter vinelandii NifV rescued the defect in nitrogen-fixing activity of the fen1 nodules. Exogenous supply of homocitrate also recovered the nitrogen-fixing activity of the fen1 nodules through de novo nitrogenase synthesis in the rhizobial bacteroids. These results indicate that homocitrate derived from the host plant cells is essential for the efficient and continuing synthesis of the nitrogenase system in endosymbionts, and thus provide a molecular basis for the complementary and indispensable partnership between legumes and rhizobia in symbiotic nitrogen fixation.