Chondroblastoma in the Children Treated with Intralesional Curettage and Bone Grafting: Outcomes and Risk Factors for Local Recurrence.

OBJECTIVE: To review the outcomes of surgical management in the pediatric patients with extremity chondroblastoma. Especially the risk factors of recurrence and growth disorder. And discuss a potential method to decrease the rate of growth disorder by preventing the premature physeal closure. METHODS: Fifteen girls and twenty-seven boys aged from two to 14 years (mean, 11 years) with histologically proven chondroblastoma, who presented from January 2011 to June 2018 at our Hospital, were retrospectively reviewed. Clinical data, radiographic images, histological findings, treatment, functional outcomes, and local recurrence rate were analyzed. Surgical treatment included complete curettage of the tumor and the walls of the lesion followed by bone grafting, No adjuvant methods were used. Recurrence was defined as a return of symptoms and an expansion radiolucency at the operated site. It was confirmed by the histopathological analysis. When recurrence was diagnosed, the medical data were analyzed to detect the effect of different factors on local recurrence. Functional outcome was measured according to Sailhan's functional criteria, designed to provide a standardized method of assessing pediatric chondroblastoma patient postoperatively. RESULTS: The proximal part of the femur was the most frequently involved site. All the patients had at least 24 months of follow-up; mean duration was 30 months (range, 24-60 months). The local recurrence rate was 9.5%. Three resolved after repeat surgeries without further recurrence, one had a second recurrence and received another more aggressive curettage. Local recurrence of chondroblastoma was associated with age (P < 0.05), while not associated with sex, tumor location, the radiological character of the lesion or the grafting method (P > 0.05). No pulmonary metastasis was noted at latest follow-up. Five patients suffered from premature closure of physis due to physis injury. Thirty-one patients (73.8%) had a good outcome, and all returned to normal unrestricted activities. Six patients (14.3%) had a fair outcome due to occasional pain, asymmetric range of motion, or radiographic joint changes without arthritis. And five patients (11.9%) had a poor outcome because of chronic pain, loss of joint motion impairing normal life activities, or a limb-length discrepancy and limp. CONCLUSIONS: Aggressive curettage and bone grafting resulted in local control and good outcomes in most pediatric patients. Being less than 12 years of age was the risk factor for recurrence. For those growing patients, premature physeal closure was observed after the curettage, interpositional technique with PMMA would be a good choice for prevention.

[Comparison of the estrogenic activity of organic compounds in source water and finished water from the Yangtze River and Taihu Lake in certain areas of Jiangsu Province].

A total of 43 source water and finished water samples were collected from the Yangtze River and Taihu Lake in WX and SZ areas of Jiangsu Province from October 2010 to March 2012. The XAD-2 resin was applied to absorb the organic compounds in each water sample respectively. After the procedure of elution, concentration and drying, nonvolatile organic compounds (NVOCs) were obtained. The recombinant yeast estrogen screen test was then applied to evaluate the estrogenic activities of NVOCs in each water sample. The results showed that all of the source water collected from the Yangtze River and Taihu Lake possessed estrogenic activities. The EEQ values of source water from Taihu Lake were 0.04-2.07 ng x L(-1), and the volume of EC(25-E2) were 9.06-31.62 mL; the EEQ values of source water from Yangtze River were 0.69-1.15 ng x L(-1), and the volume of EC(25-E2) were 9.06-31.62 mL. The samples from Taihu Lake in SZ area had higher estrogenic activities than the samples collected from WX area. No estrogenic activity was detected in 58.3% of the finished water samples after the treatment in water plants. The water plants which collected source water from the Yangtze River and from Taihu Lake reduced the estrogenic activities by 80.3% -100% and 55.5% -100%, respectively.

[Experimental study of core binding factor a1 gene-modified rabbit skin fibroblasts enhance bone defect repair].

OBJECTIVE: To investigate bone defect healing by true bone ceramic complex carrying core binding factor a1 (Cbfa1) gene modified rabbit skin fibroblasts. METHODS: Transfect rabbit skin fibroblasts (RSF) with both eukaryotic expression vector pSG5 which could express Cbfa1 gene and pSG5. After being cultured for 48 h, the transfected RSF were seeded into true bone ceramic (TBC) of 2 cm in length and 4 mm in diameter to construct pSG5-Cbfa1/RSF/TBC complex and pSG5/RSF/TBC complex. Forty-eight bone defect model rabbits were randomized into four groups, each has 6 rabbits (12 radius), due to different treatment. group I: with pSG5-Cbfa1/RSF/TBC complex, group II: with pSG5/RSF/TBC complex, group III: with TBC, Group IV: empty control. After being seeded and cultured for about 24 h the complexes were implanted into 2 cm long bone defects in the middle of bilateral radius of rabbits. The radius were inspected by X-ray and then the specimens were collected at the end of the fourth and twelfth weeks after operation. Then, the specimens were decalcified and histologically investigated with Hematoxylin eosin staining and Masson staining methods. Newly synthesized trabecular bone was inspected by image analysis system and the strength of bone defect area treated with graft-implantation was tested with biomechanical method-three point bending test. RESULTS: In group I, trabecular bone was actively synthesized to generate a great amount of trabecular bone and osteon. Preliminary union and bone defect healing were completed with good biomechanical characteristics. There were no newly synthesized trabecular in the other three groups, and bone defect healing were not discovered. The amount of newly synthesized trabecular bone and the results of biomechanical testing differed significantly between group I and the other three (P < 0.01). The efficacy of group I was significantly better than that of the other three groups. CONCLUSION: True bone ceramic complex composed with Cbfa1 gene modified rabbit skin fibroblasts can effectively heal bone defect in rabbits.

[Osteogenesis of rabbit skin fibroblast transfected with core binding factor a1/osteoblast specific transplanting factor-2 gene].

OBJECTIVE: To study osteoblastic phenotype expression of New Zealand rabbit skin fibroblasts transfected with mouse core binding factor a1/osteoblast specific transplanting factor-2 gene (Cbfa1/Osf2). METHODS: Cbfa1/Osf2 gene, engineered into eukaryotic expression vector pSG5, was introduced into New Zealand rabbit skin fibroblasts with catholyte liposomes-Lipofectamine 2000. Meanwhile, those transfected pSG5 and un-transfected were set the control groups. The expression of Cbfa1 gene, osteocalcin (OCN) gene, alkaline phosphatase (ALP) gene and pre-peptide 2 alpha gene of collagen type I were detected by RT-PCR assay. Cbfa1 protein was detected by Western-Blot assay, in-cell ALP activity by p-nitrophenyl phosphate (PNPP) assay and OCN content in the supernatant by radio-immunity method. The ossification nodules was detected by Alizarin-Red staining and scanning electron microscope. RESULTS: Cbfa 1mRNA and Cbfa1 protein were expressed in New Zealand rabbit skin fibroblasts transfected with pSG5-Cbfa1/Osf2 from the first day to the fifth day, but they were not detected in the control groups. In the pSG5-Cbfa1/Osf2 transfected group, the expression of ALP gene and OCN gene were respectively induced from the third day and the forth day, pre-peptide 2 alpha gene of collagen type I was enhanced from the third day. From the sixth day, ALP activity greatly increased, OCN strongly secreted, and they were maintained at a high level for about 4 weeks, and the difference was significant compared with the control group (P < 0.05). On the forty-second day, ossification nodules were found on the surface of pSG5-Cbfa1/Osf2 gene transfected cells. CONCLUSIONS: New Zealand rabbit skin fibroblasts transfected with pSG5-Cbfa1/Osf2 can express osteogenesis-related genes and proteins, and form ossification nodules on their surface.

[Progress on the related mechanism in the development of bone and joint].

The embryonic development of bone and joint involves in complicated events for vertebrate limb. It originates from determined condensation of mesenchymal cells from lateral mesoderm. These cells and the overlying ectodermal jacket form limb buds at presumptive limb levels. Then, under the control of systemic factors, mesenchymal cells aggregate and differentiate to form cartilage blastemal elements that prefigure skeletal limb components. The latter develops into skeleton through endochondral ossification. The majority of the bones of the limb form by the endochondral mechanism. The formation of synovial joint system and bone development occur simultaneously. This article reviewed the progress on the related control mechanism in the development of bone and joint recently.

[Mechanism of the WNT family in vertebrate skeleton development].

Skeletal elements of vertebrate limb are derived from mesenchymal cells. Initially, these cells differentiate into chondrocytes which form the initial anlage element. Subsequently, chondrocytes in the middle of the cartilage element exit the cell cycle and are eventually replaced by bone through endochondral ossification. Recently, it is shown that the secreted signaling molecules encoded by members of the wnt gene family and their related elements play pivotal roles in the process of the skeleton system development. These molecules ensure the chondrocytes can differentiate continuously at proper speed in the definitive space by the negative and positive control effect on different steps of the chondrocyte differentiation and form the matural skeleton system possessing normal function and structure. However, both the members of WNT family and their related molecules in the signaling pathway expressing abnormally can disrupt the balance remained by the WNT family and result in skeleton malformation. Understanding the roles of the WNT family is helpful to explore the mechanism of vertebrate skeleton development.