By using undecalcified bone sections, accompanied by tetracycline double labeling and analysis of infrared spectrogram, the bone formation, mineralization and crystal feature of induced ectopic bone and self femora in rats were compared. The results showed that from the 21th day to the 26th day as well as from the 26th day to the 30th day of the experiment, the rate of induced bone formation, mineralization was more active than that of the self femora: on the 30th day, in the induced bone, the count of bone cell was much more, the volume of bone cell was much larger too; but the crystal structure of induced bone was indentical with that of self femora. The molecular formula was Ca_5[(OH)/(PO_4CO_3OH)_3].

Objective To investigate the changes in the expression of matrix metalloproteinase-1 (MMP-1),matrix metalloproteinase-3 (MMP-3) and tissue inhibitor of metalloproteinase-3 (TIMP-3) in the articular cartilage of patients with Kashin-Beck disease (KBD) and the role of these proteins in pathogenesis of KBD.Methods The postoperative cartilage samples were collected from patients with KBD,osteoarthritis and patients with non-bone disease (control).The expression of MMP-1,MMP-3 and TIMP-3 in the cartilage was detected by immuohistochemistry,and the positive chondrocytes were counted in different layers of the articular cartilage under microscope.Results The positive rates of MMP-1 in the upper [(67.00 ± 1.69)％] and deeper [(22.07 ± 29.66)％] layers of articular cartilage from patients with KBD,and in the deeper layer of articular cartilage from patients with osteoarthritis [(70.52 ± 37.84)％] were significantly higher than those in the control group [(51.73 ± 36.74)％,(3.75 ± 6.85)％,all P ＜ 0.05].The positive rates of MMP-3 in the deeper layer of articular cartilage from patients with KBD [(28.84 ± 31.13)％] and in the middle and deeper layers of articular cartilage from patients with osteoarthritis [(55.69 ± 35.00)％,(45.96 ± 35.38％)] were significantly higher than those in normal cartilage [(34.09 ± 28.54)％,(14.46 ± 18.32)％,all P ＜ 0.05].The positive rates of TIMP-3 in the middle layer of articular cartilage from patients with KBD [(21.25 ± 25.23)％] and in the middle and deeper layers of articular cartilage from patients with osteoarthritis [(20.40 ± 22.19)％,(18.10 ± 22.58)％] were significantly lower than those in normal cartilage [(36.74 ± 26.61)％,(7.81 ± 20.58)％,all P ＜ 0.05].Conclusion MMP-1,MMP-3 and TIMP-3 play important roles in the articular cartilage damage of KBD.

Objective To investigate the apoptosis of articular chondrocyte and the expression of Bcl-2, Bax, Fas and iNos in articular cartilage with Kashin-Beck disease(KBD) in order to understand the pathogenesis of chondronecrosis in KBD. Methods The collected samples of human articular cartilage were divided into two groups: control group (15 samples from 15 cases), KBD group (15 samples from 15 cases). KBD patients were diagnosed by "Pathological Criteria to Diagnose KBD in China". Chondrocyte apoptosis was detected by TUNEL staining, and the Bcl-2, Bax, Fas and iNos positive articular chondrocytes were stained by the B-SA of immunohistochemistry. Articular cartilage was classified three zones and the positive rate were counted by light microscope for cytoplasimic staining by polyclonal antibodies of Bcl-2, Bax, Fas and iNos and apoptotic chondrocytes by TUNEL. Results ① The percentage of positive apoptotic chondrocytes stained by TUNEL in the middle zone of articular cartilage from the KBD-children group(33.60±2.71%) was higher than that of the control (1.33±0.41% t=11.59, g=28, P<0.01). ②The percentage of chondrocytes staining for Bcl-2, Bax, Fas and iNos among the upper and the middle zone in KBD group were significantly higher than that of the control (t=11.75-18.65, g=14, P<0.01); the remarkable difference in the expression of Bcl-2, Bax, Fas and iNos among the upper, the middle and the deep zones was also seen in KBD articular cartilage (F=73.49-114.42, g=42, P<0.01), and staining for Bcl-2, Bax, Fas and iNos in KBD children was prominent in the upper zone(41.93±12.26%, 45.60±15.78%, 53.60±16.49%, 45.47±14.02%) and the middle zone(14.93±3.50%, 13.87±4.32%, 23.27±4.83%, 21.67±6.82%)of articular cartilage, respectively. Conclusion The chondrocyte apoptosis and the present of Bcl-2, Bax, Fas and iNos positive chondrocytes in articular cartilage of children with KBD were significantly higher than that of the control.

Objective To investigate the expressions of interleukin-1β(IL-1β), interleukin-6(IL-6) and tumor necrosis factor alpha(TNF-α) in cartilage of children with Kashin-Beck disease(KBD) in order to provide a possible mechanism of the disease. Methods Articular cartilage tissues of 5 KBD children(KBD group) were selected from KBD children autopsy samples keeping in Institute of Endemic Diseases, Medical School of Xi’an Jiaotong University; articular cartilage tissues of 5 normal children ( control group ) were selected from non-KBD areas of Shaanxi Province, three cases were from accident death children, two cases were the samples of congential malformation of six finger. Expressions of IL-1β, IL-6 and TNF-α in the cartilage were detected using immunohistochemistry; the cells of articular cartilage were divided into three areas (superficial zone, middle zone and deep zone) to analyze the expressions of IL-1β, IL-6 and TNF-α. Results The expressions of IL-1β in superficial zone , middle zone and deep zone of articular cartilage of KBD group (63.50 ± 7.19, 54.75 ± 5.50, 66.20 ± 9.91) were significantly higher than those of control group(5.75 ± 1.26, 0.00 ± 0.00, 0.00 ± 0.00, all P<0.05). The expression of IL-6 in superficial zone of articular cartilage in KBD group(55.25 ± 6.24) was significantly higher than that of control group(0.00 ± 0.00, P<0.05). The expressions of TNF-αin all zone of articular cartilage of KBD group(33.25 ± 6.50, 3.75 ± 0.96, 29.80 ± 1.92) were significantly higher than those of control group (3.74 ± 0.82, 0.00 ± 0.00, 0.00 ± 0.00, all P < 0.05). Conclusion The levels of IL-1β, IL-6 and TNF-α are up-regulated in articular cartilage of KBD children, suggesting that cytokines may play an important role in matrix degradation in KBD children cartilage.

Objective To investigate and analyze the preventive effect of boron on the cartilage damage in rats with intake excessive fluoride. Methods Fifty-ix Sprague-Dawley rats were divided into the control group (C, intake distilled water), the excessive fluoride dose group (EF, intake distilled water with 100 ppm F-) and the boron prevention group (P, intake distilled water with 100 ppm F- as well as the supplemental boron dietary). 3 to 5 months later, fluorine contents in serum, RNA contents in costal cartilage were assayed. The morphological changes in tibia growth plate cartilage (GPC) in rats were observed. Results Although exposed to the same dose of fluoride, the fluorine contents in serum in rats of P group decreased notably compared with those of EF group, the damage of tibia GPC under optical and electron microscope lessened significantly, and RNA contents in costal cartilage increased obviously in the 3rd month. Conclusion Boron added could decrease the fluorine level in the body and relieve the toxic symptom of excess fluoride, and thus boron has a preventive effect on skeletal fluorosis.

Objective To examine matrix proteoglycan metabolic markers and probe into the turnover of matrix proteoglycan and enzyme-mediated role of matrix metalloproteinases (MMPs) and aggrecanases in reparative tissues with tissue engineering cartilage. Methods Tissue-engineered cartilage was constructed by cancellous bone matrix gelatin (BMG) with allogeneic chondrocytes in vitro for 2 weeks, then implanted to repair osteochondral defects of rabbit knee joint. Samples were obtained 6 months later to explore the expressions of 3-B-3(-) epitope, MMPs, MMP-generated epitope BC-4 and aggrecanases-generated epitope BC-13. Results In repaired tissues, the expression of 3-B-3(-) epitope increased, but that of MMPs and MMP-generated epitope BC-4 reduced. There was no expression of aggrecanases-generated epitope BC-13. Conclusion Expressions of 3-B-3(-), MMPs, BC-4 and BC-13 can help probe into the matrix proteoglycan turnover in reparative cartilage tissues. Anabolism exceeds catabolism in the repaired tissues. MMPs play an important role in the conservative baseline turnover of proteoglycan and remodeling of the graft tissues.

OBJECTIVETo compare the expressions of programmed cell death 5 (PDCD5) and early growth response protein-1 (EGR-1) in the articular cartilage between Kashin-Beck disease (KBD) and primary osteoarthritis and the roles of these factors in KBD cartilage.

METHODSCartilage specimens were collected from 10 confirmed KBD patients, 15 osteoarthritic patients and 6 healthy subjects. The expression levels of PDCD5 and EGR-1 in the cartilage were detected by immunohistochemistry staining, and the positive chondrocyte counts were recorded in the different layers of KBD and OA cartilages.

RESULTSThe KBD cartilages contained a significantly higher percentage of PDCD5-positive chondrocytes in the middle layer [(41.35 ± 2.97)%] than OA cartilages [(26.48 ± 2.04)%, P=0.001] and normal cartilages [(19.02 ± 1.88)%, P=0.000] with also obvious PDCD5 over-expression in the deeper layer compared to OA (P=0.000) and normal cartilages (P=0.029), but PDCD5 expression in the superficial layer of the cartilages showed no significant difference among the 3 groups(P>0.05). The average EGR-1 positivity rate in the superficial layer of the cartilage was significantly higher in KBD patients than in OA patients (P=0.000) and healthy controls (P=0.000), but in the middle layer, its positivity rate in KBD patients was higher than that in the normal control (P=0.017) but lower than that of OA cartilage (P=0.002); EGR-1 expression in the deeper layer was comparable in KBD and OA cartilages but both was higher than that in normal cartilages. PDCD5 and EGR-1 expressions were not correlated in either KBD or normal cartilages, but were positively correlated in the superficial layer of OA cartilages.

CONCLUSIONSKBD cartilages show a significantly increased PDCD5 expression in the deeper layer and enhanced EGR-1 expression in both superficial and deeper layers, suggesting the involvement of PDCD5 and EGR-1 in the pathogenesis of KBD.

Apoptosis ; Apoptosis Regulatory Proteins ; metabolism ; Cartilage, Articular ; metabolism ; pathology ; Chondrocytes ; metabolism ; Early Growth Response Protein 1 ; metabolism ; Humans ; Immunohistochemistry ; Kashin-Beck Disease ; metabolism ; Neoplasm Proteins ; metabolism ; Osteoarthritis ; metabolism ; Transcriptome