In this paper, a method for dose calculation with pencil beam kernels constructed by point kernel superposition was proposed to accelerate the dose calculation during intensity optimization iteration. With this method, the direct aperture optimization method can be integrated in the planning system based on point kernel convolution/superposition model. The dose calculation time was also reduced during the iteration. From the result of the phantom and clinical patient data test, it was concluded that this method could be used for the intensity optimization of iteration dose calculation as the satisfied precision due to the optimization result coherence obtained. By implementing the method in the planning system product based on point kernel convolution/superposition model, a lot of additional research and development works for the pencil beam dose calculation model as well as the product maintenance cost can be avoided.
目的:研究缺氧预处理对老年大鼠子宫及双附件切除术后疲劳是否有改善作用,并通过对比观察超氧化物歧化酶及丙二醛水平的变化,初步探讨缺氧预处理的作用机制。方法:将老年大鼠分为空白对照组、对照组、缺氧预处理三组。空白对照组为假手术组,对照组为子宫及双附件切除术组, 缺氧预处理组为缺氧预处理加子宫及双附件切除术组。对比观察缺氧预处理对大鼠体力活动及血清超氧化物歧化酶和丙二醛水平的影响。结果:空白对照组、对照组、缺氧预处理三组大鼠悬尾不动时间分别为:(21±3)s,(83±10)s,(44±5)s,各组间比较Plt;0.05。三组SOD活性分别为:(131.23±5.31)U/L,(36.12±9.68)U/L,(73.01±9.82)U/L,各组间比较Plt;0.05。三组MDA水平分别为:(9.78±1.26)μmol/L,(29.87±3.13)μmol/L,(15.98±2.21)μmol/L,各组间比较Plt;0.05。结论:缺氧预处理可提高老年大鼠的抗氧化能力,对老年大鼠子宫及双附件切除术后疲劳综合征有明显的改善作用。
ObjectiveTo review the research progress focused on the effects of strontium ranelate (SR) on osteoarthritis. MethodsThe relevant literature about the effects and mechanism of SR intervening osteoarthritis in recent years was extensively reviewed and comprehensively analyzed. ResultsSR not only could improve the microenvironment of bone metabolism in articular cartilage with osteoarthritis, promote activity of osteoblasts, and inhibit activity of osteoclasts, but also could adjust the expression of key proteases which affect cartilage formation, and therefore it has a potential protective effect on subchondral bone during the progression of osteoarthritis cartilage. ConclusionSR is expected to become a drug of osteoarthritis disease remission, but further studies are needed to clarify the mechanism of SR in osteoarthritis, and finally confirm the best application dosage of SR in osteoarthritis treatment.
Objective To discuss the effectiveness and the safety of accurate decompression via foraminoplasty in treating lumbar lateral recess stenosis patients who accompanied by disk-flavum ligamentum space and bony lateral recess stenosis, and to analysis the short-term effectiveness of the surgical procedures. Methods Forty-five lumbar lateral recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis were treated by accurate decompression via foraminoplasty between January 2013 and January 2016. There were 29 males and 16 females with a median age of 58 years (range, 42-82 years). The disease duration was 3-96 months (mean, 24.4 months). The lesion segment included L4, 5 in 36 cases and L5, S1 in 9 cases. The visual analogue scale (VAS) score of low back pain and leg pain at preoperation and last follow-up were recorded, and the modified Macnab criteria was used to evaluate the effectiveness at last follow-up. Postoperative CT and MRI were reviewed to evaluate the stability and decompression of the lumbar spine. Results All operations were successfully completed. All the 45 patients were followed up 3-18 months (median, 11 months). Dural tear occurred in 2 cases during operation, bone graft removed into the spinal canal in 1 case, postoperative low back pain occurred in 5 cases, and there was no nerve root injury, hematoma formation, or other complications. The leg pain VAS score at last follow-up (0.6±1.2) was significantly improved when compared with preoperative score (5.7±1.4) (t=8.981, P=0.001); and the low back pain VAS scores showed no significant difference between preoperation and last follow-up (1.5±1.3vs. 1.7±1.4;t=0.535, P=0.585). According to the modified Macnab criteria, the results were excellent in 20 cases, good in 22 cases, fair in 2 cases, and poor in 1 case at last follow-up, and the excellent and good rate was 93.3%. Conclusion Accurate decompression via foraminoplasty is an effective, safe, and less invasive way for treating lumbar recess stenosis patients accompanied by disk-flavum ligamentum space and bony lateral recess stenosis.
People’s understanding of lumbar spinal stenosis has become more and more comprehensive and reasonable, however, there are still many controversies about the concepts of " central lumbar canal” and " lateral lumbar spinal canal”, and there is no unified standard at present. In this paper, we redefine and differentiate the two concepts. We believe that some kinds of central canal stenosis caused by bilateral recess stenosis can be completely solved by bilateral percutaneous endoscopic transforaminal discectomy. At the same time, the concept of " lumbar lateral recess” is ambiguous. We redefine it as " lateral lumbar spinal canal” and propose " West China Hospital classification” to guide surgical decision-making, which has been widely recognized and applied.
ObjectiveTo assess the reliability, effectiveness, and the safety of full endoscopic transforaminal decompression (FETD) under local anesthesia guided by the classification of lateral region of the lumbar spinal canal (CLLSC) in treating lumbar spinal stenosis (LSS) in geriatric patients.MethodsThe clinical data of 63 geriatric patients with LSS met the inclusion criteria underwent FETD surgery between June 2015 and July 2017 were retrospectively analyzed. There were 37 males and 26 females, with a median age of 76 years [interquartile range (IQR), 73-80 years], and a median symptomatic duration of 55 months (IQR, 16-120 months). There were 17 cases of grade B and 46 cases of grade C based on the Schizas morphological grading system. CLLSC was used for imaging evaluation for the stenotic condition, and intra-class correlation coefficients (ICC) were used to test intra-observer and inter-observer reliability of CLLSC. The stenotic condition of patients was re-evaluated by the surgeon after operation, and the results were compared with the findings of preoperative CLLSC. The visual analogue scale (VAS) score for low back pain and leg pain recorded before operation, and at 1 day, 3 months, and 6 months after operation, and last follow-up were used to assess the pain relieving; the functional improvement was evaluate by Oswestry disability index (ODI); the modified Macnab criteria were used to self-evaluate the surgical satisfaction.ResultsThe operation were successfully performed for all patients, with a median operation time of 75 minutes (IQR, 65-85 minutes), postoperative hospitalization stay of 48 hours (IQR, 48-72 hours), and the time to ambulation after operation of 24 hours (IQR, 24-24 hours). Sixty-three patients were followed-up and with a median follow-up time of 18 months (IQR, 13-20 months). Based on preoperative CLLSC classification, there were 72 stenotic zones, distributed 16 in zone 1, 6 in zone 2, 3 in zone 3, 2 in zone 4, 7 in zone 5, 34 in zones 1+2, 2 in zones 3+4, and 2 in zones 4+5. Perioperative complications occurred in 4 cases (6.3%), including 2 cases of intraoperative dural sac tear, 1 of preoperative numbness symptom aggravation, and 1 of postoperative urinary retention. VAS score of leg pain and ODI score at each time point after operation were significantly improved compared with those before operation (P<0.05). VAS scores of low back pain showed no significant difference between pre- and post-operation (P>0.05). At last follow-up, based on the modified Macnab criteria, 19 cases were excellent, 37 were good, 6 were fair, and 1 was poor, and the excellent and good rate was 88.9%. The reliability analysis showed that CLLSC had substantial intra-observer reliability in the geriatric population, with an average ICC of 0.78. There was also a substantial inter-observer reliability, with an average ICC of 0.73. While comparing the preoperative CLLSC results with the postoperative CLLSC results, 53 patients (73.6%) were in full agreement, 15 patients (20.8%) were in partial agreement, and 4 patients (5.6%) were not.ConclusionCLLSC has high reliability in the diagnosis of LSS in the geriatric patients. Combined FETD with CLLSC, accurate diagnosis, and minimal invasion can be performed to achieve safe and effective result.
ObjectiveTo explore the value of procalcitonin-to-albumin (PAR) in patients with acute respiratory distress syndrome (ARDS).MethodsA retrospective study was carried on patients diagnosed with ARDS from December 2016 to March 2018. The receiver-operating characteristics (ROC) curve was used to identify the cutoff value of PAR. The association of PAR and 28-day mortality was evaluated using univariate and multivariable Cox regression.ResultsIn the final analysis, there were a total of 255 patients included. Of whom 164 (64.3%) was male, 91 (35.7%) was female and the mean age was 52.1±14.5 years old. The 28-day mortality of all the patients was 32.9% (n=84). ROC curve revealed that the cutoff value of PAR was 0.039 (specificity: 0.714, sensitivity: 0.702) and area under the curve was 0.793 (95%CI: 0.735 - 0.850, P<0.001). The following variables were considered for multivariable adjustment: age, body mass index, pneumonia, aspiration, sepsis, surgery, PaO2/FiO2, red blood cell counts and PAR (P<0.01 in univariate analysis). After multivariable analysis, only age (HR: 1.033, 95%CI: 1.009 - 1.059, P=0.008), PaO2/FiO2 (HR: 0.992, 95%CI: 0.985 - 1.000, P=0.044) and PAR (HR: 4.899, 95%CI: 2.148 - 11.174, P<0.001) remained independently associated with 28-day mortality (P<0.05).ConclusionHigh PAR predicts a poor outcome in ARDS patients, therefore it appears to be a prognostic biomarker of outcomes in patients with ARDS.
ObjectiveTo investigate the role of Aspergillus in the severe refractory exacerbations of chronic obstructive pulmonary disease (COPD).MethodsThe clinical data of two COPD patients suffering from refractory acute exacerbations were analyzed and the relevant literature were reviewed.ResultsTwo patients were male, aging 72 and 64 years respectively. Both of them had a history of frequent acute exacerbations with severe COPD recently. Meanwhile, they received intravenous use of antibiotics repeatedly, one of them took oral corticosteroids to control wheezing, but failed. Their serum Aspergillus-specific IgG antibody was weakly positive. Besides traditional treatment, they received additional antifungal therapy, and the symptoms alleviated. There was no acute exacerbation in the half a year follow-up period after appropriate therapy.ConclusionsAspergillus colonization, sensitization, infection should be considered in patients with severe COPD. When Aspergillus-associated evidence are acquired, antifungal therapy will be unexpected helpful.