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Objective:To investigate the feasibility of establishing a canine model of lumbar intervertebral disc degeneration through the application of cumulative axial load and a six-phase combined motion on the vertical sitting dog's lumbar spine.Methods:Twenty adult female grass dogs, each weighing 10.0±0.5 kg, were randomly divided into two groups, with 10 dogs in each group. In the model group, dogs were secured to an exercise machine in a vertical position, and six phases of lumbar spine movement (flexion and extension, left and right lateral flexion, left and right rotation, 45° each) were combined with a specific number of cycles under continuous axial load (245 N). In the control group, dogs were secured to the exercise machine in a vertical position without any intervention. Radiographic examinations were performed before and after 20,000, 50,000, 100,000, and 150,000 compound exercises in the model group. The disc height index (DHI) was measured through lateral X-ray, and MRI T2-mapping was used for quantitative analysis of intervertebral disc degeneration. When intervertebral disc degeneration was evident on MRI T2-weighted imaging (modified Pfirrmann system > Grade V), the combined motion was halted. Micro-CT quantitative analysis of bone mineral density (BMD) in the upper and lower endplates, trabecular bone structure, and histological staining (HE staining, "O" staining, Sirius red staining) were employed to verify and assess the degree of intervertebral disc degeneration.Results:After 50,000 compound exercises, mild degeneration of the intervertebral discs at L 6-7 and L 7S 1 was observed on T2-weighted imaging. With the accumulation of exercise load, the degree of degeneration progressively increased, reaching a moderate degree of degeneration after 100,000 composite exercises, and DHI began to decrease. Mild degeneration was also observed in the upper L 5-6 intervertebral disc. When the cumulative exercise volume reached 150,000 repetitions, the height of intervertebral spaces in the L 5-6, L 6-7, and L 7S 1 segments further decreased, and the intervertebral discs exhibited severe degeneration (improved Pfirrmann grading system Grades IV-VI). The upper L 4-5 intervertebral discs also displayed mild degeneration. Histological scores were as follows: L 5-6 (8.2±0.8), L 6-7 (9.5±0.7), and L 7S 1 (10.3±0.5), indicating a degree of degeneration in the order of L 5-6<L 6-7<L 7S 1. HE and safranine "O" staining confirmed the significant collapse of the intervertebral spaces in the L 5-6, L 6-7, and L 7S 1 segments, characterized by severe shrinkage of the nucleus pulposus tissue, a disordered internal structure, and nearly absent vacuolar-like nucleus pulposus cells. Sirius red staining revealed pronounced folds, disordered arrangement, and multiple fractures in the fibers of the anterior and posterior rings of the intervertebral disc. The posterior ring of the disc exhibited more pronounced changes than the anterior ring, and the thickness of the bone endplate and bone trabecular density became thinner and less dense. Micro-CT quantitative analysis further confirmed that the BMD and number of trabeculae in the upper and lower endplates of the L 5-6, L 6-7, and L 7S 1 segments were significantly lower than those in the control group and other segments of the model group, while the trabecular separation was significantly higher than that in the control group and other segments of the model group. Conclusion:The utilization of the "Lumbar Composite Exercise Machine" can effectively replicate the biomechanical and kinematic characteristics of human lumbar intervertebral discs. Cumulative axial load and six-phase composite exercise can induce varying degrees of chronic degeneration in canine lumbar intervertebral discs, which is related to the exercise load, particularly in the L 5-6, L 6-7, and L 7S 1 segments.
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Objective:To evaluate the clinical application of online adaptive radiotherapy based on iterative cone-beam computed tomography (iCBCT) for the pelvic malignancies.Methods:This was a prospective clinical trial of iCBCT guided online adaptive radiotherapy for pelvic malignancies in Department of Radiation Oncology, Peking Union Medical College Hospital. Clinical data of 13 patients with pelvic malignancies who received online adaptive radiotherapy from August to November, 2022 were preliminarily analyzed (2 cases of cervical cancer, 4 postoperative cervical cancer, 3 postoperative endometrial cancer, 3 bladder cancer and 1 prostate cancer). The feasibility of online adaptive radiotherapy, adaptive radiotherapy time, the frequency and magnitude of edits for organs at risk and target volume, target volume coverage and organs at risk doses were analyzed. Statistical analysis was performed by SPSS software. Data conforming to normal distribution were described by Mean±SD, and data with non-normal distribution were expressed by M ( Q1, Q3). Data with homogeneous variances were analyzed by t-test, and data with non-normal distribution or heterogeneous variances were analyzed by nonparametric test. Results:The average adaptive time was 15 min and 38 s (from acceptance of acquired CBCT scan to completion of the final plan selection). 85.4% (830/972 fractions) of influencer structures (system-defined organs adjacent to and with high impact on the generation of clinical target volume and planning target volume, primarily bladder, rectum and small intestine in pelvic neoplasms) automatically generated by artificial intelligence required no edits or minor editors, and 89.8% (491/547 fractions) of clinical target volume automatically generated by artificial intelligence required no edits or minor editors. The adapted plan was adopted in 98.5% (319/324 fractions) of radiotherapy fractions. Compared with the scheduled plan, the adapted plan showed better target volume coverage and reduced the dose of organs at risk.Conclusions:iCBCT guided online adaptive radiotherapy for the pelvic malignancies can be achieved within clinically acceptable timeslots. In addtion, better dose coverage of target volume shows the advantages of online adaptive radiotherapy.
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Objective: To compare the effectiveness of short-segment and long-segment bone cement-augmented fixation combined with vertebroplasty in treatment of stage Ⅲ Kümmell disease. Methods: A clinical data of 44 patients with stage Ⅲ Kümmell disease met the selection criteria between January 2014 and December 2017 was retrospectively analyzed. Eighteen cases were treated with short-segment bone cement-augmented fixation combined with vertebroplasty (short-segment group) and 26 cases were treated with long-segment bone cement-augmented fixation combined with vertebroplasty (long-segment group). There was no significant difference in gender, age, disease duration, fracture segment, bone mineral density (T value), Frankle grading, and preoperative pain visual analogue scale (VAS) score, Oswestry disability index (ODI), anterior edge height of injured vertebrae, kyphosis Cobb angle, and thoracolumbar kyphosis (TLK) between the two groups ( P>0.05). The operation time, intraoperative blood loss, bone cement injection volume, bone cement leakage rate, VAS score, ODI, anterior edge height of injured vertebrae, kyphosis Cobb angle, and TLK were compared between the two groups. Results: The operation time and the intraoperative blood loss in the short- segment group were significant lower than those in the long-segment group ( P0.05). All patients were followed up 12-36 months, with an average of 24.4 months. The VAS score, ODI, anterior edge height of injured vertebrae, kyphosis Cobb angle, and TLK significantly improved at 1 week after operation and last follow-up in the two groups ( P0.05). At last follow-up, the neurological function of the two groups recovered, and there was no significant difference in Frankle grading between the two groups ( P>0.05). There were 3 cases (16.67%) of non-surgical vertebral fractures in the short-segment group and 6 cases (23.08%) in the long-segment group, showing no significant difference between the two groups ( P>0.05). Bone rejection occurred in 1 case in the short-segment group, and neither internal fixation failure nor collapse of the injured vertebrae occurred during follow-up. Conclusion: Both short-segment and long-segment bone cement-augmented fixation combined with vertebroplasty can achieve good effectiveness in treatment of stage Ⅲ Kümmell disease, and can maintain the height of the injured vertebra and prevent the collapse of the injured vertebra. Compared with long-segment fixation, short-segment fixation has the advantages of shorter operation time and less intraoperative bleeding.
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Objective To analyze the differences in immune system between Npc1 gene mutant (Npc1-/ -) and wild-type (Npc1+/ +) mice for better understanding the pathogenesis of Niemann-Pick disease type C1 (NPC1) from an immunological perspective and providing reference for NPC1 treatment in clinic.Methods Body, thymus and spleen weight of Npc1-/ -and Npc1+/ + mice aged (14±2) days, (42±2) days and (63±2) days (Day14±2 , Day42±2 and Day63±2 ) were recorded and the associated organ index were calcu-lated. White blood cell count in peripheral blood of mice aged Day42±2 was examined by routine blood test. Expression of cytokines at mRNA level in mouse peripheral blood was detected by qPCR. Percentages of CD4+, CD8+ and CD19+ lymphocytes in peripheral blood and spleen of mice aged Day42±2 were measured by flow cytometry. Apoptosis and senescence of spleen in mice aged Day63±2 were examined by immunofluores-cence and β-galactosidase staining. Results Compared with Npc1+/ + mice, there was no significant differ-ence in the weight of spleen and thymus in Npc1-/ - mice aged Day14±2; the weight of spleen in Npc1-/ - mice aged Day42±2 significantly increased, but the weight of thymus showed a significant decrease; furthermore, both the weight of spleen and thymus in Npc1-/ - mice aged Day63±2 significantly decreased; and the body weight of Npc1-/ - mice of each age group significantly decreased. Moreover, compared with Npc1+/ + mice, the absolute number of lymphocytes in the peripheral blood of Npc1-/ - mice aged Day42±2 showed no signifi-cant difference, but the percentage in whole white blood cells significantly decreased due to the significantly increased neutrophils. Expression of cytokines ( IL-1, IL-2, IFN-γ, TNF-α, IL-4, granzyme A and granzyme B) at mRNA level in the peripheral blood leukocytes of Npc1-/ - mice aged Day42±2 was abnormal as compared with that in Npc1+/ + mice. The number of T (CD4+ and CD8+) lymphocytes in Npc1-/ - mice aged Day42±2 significantly decreased, while the number of B (CD19+) lymphocytes increased significantly as com-pared with those in the Npc1+/ + mice. Compared with Npc1+/ + mice, apoptosis and senescence of the spleen in Npc1-/ - mice aged Day63±2 aggravated significantly. Conclusion The abnormal lipid metabolism triggered by Npc1 gene mutation causes severe immune dysfunction in Npc1-/ - mice. Therefore, immune dysfunction should be taken into full consideration when treating patients with NPC1, which might help improve the life quality and prolong the survival time.
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Objective To evaluate the efficacy of double-balloon dilation in percutaneous kyphoplasty for severe osteoporotic vertebral compression fracture (OVCF) in the elderly. Methods Sixty patients with severe OVCF were randomly divided into two groups, a double- and a single-balloon dilatation group,with 30 cases in each group. Regular follow-up was conducted at 3,6,and 12 months after operation. The operation time,blood loss volume,bone cement injection rate,and bone cement leakage rate were recorded. The visual analog score (VAS),Oswestry disability index (ODI),vertebral anterior height,and kyphosis Cobb angle were used to evaluate efficacy. Results No significant differences in operation time and bleeding volume were found between the 2 groups (P > 0.05). The amount of bone cement injection in the double-balloon dilatation group was more than that in the single-balloon dilatation group (P < 0.05). The bone cement leakage rate was lower in the double-balloon dilatation group,but the difference was not statistically significant (P > 0.05). No significant differences in VAS score and ODI were found between the 2 groups at 1 day and 3,6,and 12 months after operation (P >0.05),but with significant differences in the anterior vertebral height and kyphosis Cobb angle (P < 0.05). During the follow-up,2 cases of complication occurred in the double-balloon dilatation group,but 6 cases of complication occurred in the single-balloon dilatation group. Conclusion Double-balloon dilation in percutaneous kyphoplasty for elderly patients with severe OVCF can effectively alleviate clinical symptoms and reduce complications,which is an effective method for the treatment of severe OVCF.
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BACKGROUND: As a minimally invasive technology, percutaneous vertebroplasty is a safe and effective treatment for osteoporotic vertebral compression fractures.OBJECTIVE: To overview the research progress concerning the biomechanical properties, bone strength maintenance, bone absorption and degradation of bone filling materials used in percutaneous vertebroplasty.METHODS: The first author conducted a computer-based retrieval of CNKI, PubMed and Medline databases for relevant articles published from January 2005 to May 2016. The keywords were bone cement, bone filling materials, percutaneous vertebroplasty in English and Chinese, respectively.RESULTS AND CONCLUSION: Polymethyl methacrylate is not an ideal material for osteoporotic vertebral compression fractures. Calcium phosphate cement and calcium sulfate cement can replace the traditional polymethyl methacrylate; however, some problems still exist, such as poor effect of venography, incontrollable biological degradation rate, and lack of the evidence-based medicine about its long-term effect. Composite bone cement, as a good bone repair material, holds the advantages of various bone cements. As the composite bone cement has just been introduced in clinical practice, its long-term curative efficacy needs to be further studied.
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Objective:To analyze the morphological characteristics of maxillary first molars,mesiobuccal roots and the incidence of second mesiobuccal(MB2)roots in Uyghur adults.Methods:1 00 Uyghur adults with full dentition were included.The morphology of maxillary first molars and root canals were examined by cone beam computerized tomography(CBCT).The prevalence of MB2 and the difference between sexes were analysed.Results:Among 200 maxillary first molars,1 54(77%)teeth were with 3 roots and 3 ca-nals,42(21 %)with 3 roots and 4 canals,2(1 %)with 3 roots and 5 canals,1 (0.5%)was with 4 roots and 6 canal,1 (0.05%) with 4 roots and 7 canal.The percentage of type Ⅰ,Ⅱ,Ⅲ,Ⅳ and Ⅴ mesiobuccal roots was 77.0,1 3.5,9.0,0 and 0.5 respec-tively.The prevalence of MB2 was 22.32% in male and 21 .2% in female(P =0.901 ).Conclusion:The prevalence of MB2 in Uy-ghur adults is about 22% and the predominant morphology of maxillary first molarsmesiobuccal roots was type I.
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BACKGROUND:The biological function of human periodontal ligament stem cells is a hot area of research in the treatment of periodontal disease. Human periodontal ligament cells are one of the end cells derived from human periodontal ligament stem cells;meanwhile, it can also provide supports to the development of human periodontal ligament stem cells. However, few studies are reported about the difference of biological characteristics between human periodontal ligament stem cells and human periodontal ligament cells. OBJECTIVE:To compare the differences of biological characteristics between human periodontal ligament stem cells and human periodontal ligament cells. METHODS:The human periodontal ligament stem cells and human periodontal ligament cells were isolated and purified using tissue explant method and cellclone method, respectively, and then were observed under light microscope to compare the differences of morphology. cellproliferation curves of human periodontal ligament stem cells and human periodontal ligament cells were drawn respectively with cellcounting kit 8 assay. Flow cytometry analysis was used to detect their cellcircles and their surface markers expressions. The alkaline phosphatase gene, proliferating cellnuclear antigen gene and Scleraxis gene of human periodontal ligament stem cells and human periodontal ligament cells were detected by Real-time PCR assay.RESULTS AND CONCLUSION:The human periodontal ligament stem cells and human periodontal ligament cells showed a notable difference in morphology under the light microscope observation. During the first 5 days, the cellproliferation curve of human periodontal ligament stem cells was lower than that of human periodontal ligament cells, but 5 days later, the curve of human periodontal ligament stem cells was significantly higher than that of human periodontal ligament cells. The cellcircles of human periodontal ligament stem cells and human periodontal ligament cells were 41.1%and 23.9%, respectively. The surface markers of human periodontal ligament stem cells and human periodontal ligament cells were similar, but their expression rates had significant difference. The expressions of alkaline phosphatase gene, proliferating cellnuclear antigen gene and Scleraxis gene of human periodontal ligament stem cells were significantly higher than those of human periodontal ligament cells. The above results suggest that human periodontal ligament stem cells have much stronger potential ability than human periodontal ligament cells in osteogensis and cellproliferation.
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Objective To evaluate the feasibility and significance of CT image-based threedimensional (3D) brachytherapy for cervical cancer.Methods Three-dimensional (3D) plan and twodimensional (2D) plan were designed for 55 CT images of brachytherapy from 12 cervical cancer patients who received radical radiotherapy in 2013.Dosimetric comparison was performed between the 3D plan and 2D plan,and paired t-test,Wilcoxon signed rank test,Pearson correlation analysis,and Spearman correlation analysis were performed.Results A point dose,D90,V100,CI,and CI' in 3D plan were higher than those in 2D plan (P=0.015,0.016,0.000,0.000,0.000).Bladder point dose,rectal point dose,and rectal D2 cm3 in 3D plan were slightly higher than those in 2D plan,but hot spot dose was significantly reduced in 3D plan (P =0.140,0.123,0.214).Bladder D2cm3 was significantly higher than bladder point dose (P =0.000).Sigmoid colon D2cm3 was more correlated with the average doses of the three highest rectal points than rectal D2 cm3 (r =0.314,0.630,P =0.000,0.000).V100 showed a linear relationship with high-risk CTV (r =0.981,P =0.000).Bladder D2cm3 was higher than 430 cGy when the bladder volume was more than 80 cm3 ;small intestinal D2 cm3 did not change significantly when the bladder volume was less than 115 cm3,but decreased significantly once the volume exceeded the value.Conclusions Compared with the traditional 2D plan,the 3D plan for CT image-based cervical cancer brachytherapy significantly increases the target coverage and conformity index,but does not significantly increase the doses to organs at risk.Point dose evaluation is confirmed to be inaccurate.The doses to the bladder,rectum,and small intestine can be adjusted by controlling the bladder volume.
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Objective To analyze the outcomes of radiotherapy for keloids by high energy electron beams and the factors influencing the treatment outcome.Methods From Jan 1998 to Jun 2012,846lesions in 578 patients received radiotherapy.The median age is 29 years old (range 5-80 years old).There are 841 lesions with postoperative radiotherapy and 39 lesions with skin-grafting.656 lesions treated within 1 day after operations.The max diameter of 348 keloids are > 5 cm.We used 6 MeV and 7 MeV electron-beam radiation therapy.The total dose ranging from 16-18 Gy/2f (interval 1 week).Treatment fields including entire keloid scars,and any suture/puncture holes with a 1 cm-margin around the lesion were used.The skin grafting patients need radiotherapy after the flap survived (about 10-15 days after the operation).The median follow-up period was 36 months (range 8-185 months).Results There are 736 (87.0%) of 846 lesions with radiotherapy effective.Other 89 (10.5%) lesions relapse in 4-33 months (median 12 months).21 lesions were of no avail.The univarate analysis shows that keloids length,keloids location,skin-grafting,interval between operations and irradiations are the influencing factors of outcomes (P =0.007,0.000,0.000,0.001).The multivariate analysis shows that keloids location and skin-grafting remained statistically significant differences (P =0.001,0.001).Most of the recurrence cases are large and bent scars.Conclusions High-energy electron-beam radiotherapy for keloids can receive good outcomes.Treatment fields flat is very important for electron-beam radiotherapy.