Relevant literatures on the relationship betw een fluorosis and oxidative stress were reviewed.Based on most of the original papers published in recent years,we can see the increased free radicals and oxidative stress may occur in certain stage of fluoride intoxication,but confirmation of the causality between oxidative stress and fluoride-induced damages still remains much work to do.

Bone Density ; physiology ; Bone Diseases ; epidemiology ; etiology ; metabolism ; pathology ; Calcium ; metabolism ; China ; epidemiology ; Endemic Diseases ; Fluoride Poisoning ; epidemiology ; etiology ; metabolism ; pathology ; Humans ; Osteoblasts ; physiology ; Oxidative Stress ; Parathyroid Hormone ; metabolism ; Thioredoxins ; metabolism ; Transcription Factor AP-1 ; metabolism

Objective To observe endoplagmic reticulum stress in bone tissue of fluomsis rats and further explore the pathogenesis of skeletal fluorosis.Methods 48 Wistar rats were divided into 4 groups according to their body mass.The control and low.calcium group were fed with normal diet(0.79%calcium)and low-calcium diet(0.79%calcium)respectively,and both drank tap water(sodium fluoride concentrations＜1 mg/L).High fluoride and low.calcium plus high-fluoride groups were fed with normal diet(0.79%calcium)and low-calcium diet (0.79%calcium)respectively,and both drank tap water containing sodium fluoride(sodium fluoride concentrations 221 mg/L).During experimental period,rats were measured body mass once a week with a stand diet and water available ad libiturn.The experimental period was 3 months.The biochemical techniques were used to test the indicators of oxidative stress and ALP in seFum of fluorosis rats.The total RNA was extracted from the one side of the femur,and the transcription level of Bip,Xbp1,CHOP and PDI were investigated by reverse transcription polymerase chain reaction(RT-PCR).Results The level of MDA in serum of low-calcium plus high-fluoride group wag higher than that of the control[(14.74±3.11)μmol/L vs(10.15±1.96)μmol/L,P＜0.05];the activity of GPx was ma~edly higher in hish-fluoride group compared with the control[(3.87±0.41)×103 U/L vs(2.85± 0.55)×103 U/L,P＜0.05];the level of uric acid in sel'um was significantly lower both in high-fluoride group and low-calcium plus high-fluoride group compared with the respective control and the low-calcium group[(73.95± 9.52)μmol/L vs(110.43±25.48)μmol/L,(54.32±22.09)μmol/L vs(101.71±17.01)μmol/L,P＜0.05]. The activity of ALP wag obviously higher in low-calcium plus high-fluoride group compared with the control [(24.77±4.57)×103U/L vs (12.91±3.97)×103U/L,P＜0.01)].The mRNA expression of Bip/GAPDH in bone tissue was markedly higher in bone of high-fluoride group and low-calcium plus high-fluoride group compared with the control(1.38±0.24,1.35±0.12 vs 1.14±0.06,P ＜ 0.05). The expression of Xbp1/GAPDH in bone tissue significantly increased in low-calcium plus high-fluoride groups compared with the control and the low-calcium group (1.48±0.20 vs 1.02±0.25,1.07±0.25,P ＜ 0.05 or ＜ 0.01);and CHOP/GAPDH in bone tissue significantly increased in low-calcium plus high-fluoride groups compared with the control(0.84±0.18 vs 0.52±0.07,P ＜ 0.05 ). Conclusions Accelerated osteogenetic action is seen in fluorosis rats,accompanied by oxidative stress and bone endoplasmic reticulum stress,which is likely involved in the pathogenesis of skeletal fluorosis.

Objective To investigate the clinical features,treatment response and prognosis in children with Takayasu′s arteritis(TA) in order to improve the understanding of TA.Methods A retrospective study of 10 children with TA was performed.All of them were admitted and diagnosed in Peking University First Hospital from Jan.1998 to Oct.2008.The clinical features,laboratory tests,imaging modalities,treatment response and prognosis were all collected and evaluated.Results There were 3 boys and 7 girls in the 10 patients with TA,and the ratio of male to female was 12.3.The onset was from 4 months to 9 years old,with average age at 5.5 years old.The average duration of diagnosis was 7.6 months.The incidences of hypertension,vascular bruits,albuminuria,convulsion were present in 100%,100%,70% and 40%,respectively.The clinical types included typeⅡ(60%),type Ⅲ(10%) and type Ⅳ(30%).The acute phase inflammatory indices of activity such as erythrocyte sedimentation rate(ESR),C-reactive protein(CRP) and white blood cell(WBC) were not evidently increased.Tuberculosis infection was found in 6 out of 10 patients and anti-tuberculosis treatment was performed.Six patients were treated with steroids and 3 cases of them were also given immunosuppressives cyclophosphamide or methotrexate.Three of the 10 patients received anti-hypertensive and vasodilator.Two patients received percutaneous translurminal angioplasty and 1 patient received nephrectomy.One patient died of renal failure,heart failure and shock.Conclusions The patients with TA had high prevalence of tuberculosis infection,diagnosis as often late because of lack of specific clinical features at the acute inflammatory period.When organic ischaemia occurred,treatment response was usually unsatisfactory.Patients with multi-systemic and multi-viscera lesions should have comprehensive examination,especially for those with hypertension,pulseless and vascular bruits,in order to rule out TA.Early ultrasonography,computed tomography and magnetic resonnance image methods are valued in eariler diagnosis and they are the key factors to improve prognosis.

Background Corneal blindness caused by ocular surface disease is one of the main reasons for the global blinding corneal diseases.With the development and progress of tissue engineering technology,tissueengineered cornea offers a new approach to the treatment of ocular surface disease.Objective This study was to obscrve the growth and differentiation of human umbilical cord mesenchymal stem cclls (UC-MSCs) on thc corneal stroma of receipts and investigate the feasibility of human UC-MSCs differentiated into corneal epithelium-like cells and the reparation of injury cornea.Methods Human UC-MSCs were isolated from human umbilical cord using collagenase Ⅳ digestion and passaged in DMEM/F12 containing fetal bovine serum in vitro.The immunophenotype of cultured human UC-MSCs was evaluated by flow cytometry.The differentiated osteoblasts from the human UC-MSCs by directional induce was identified.Twenty-four New Zealand albino rabbits were randomly divided into 2 groups.The human UC-MSCs were cultured on porcine corneal matrix without corneal epithelium for 4 days and then transplanted onto the 12 left eyes of 12 New Zealand albino rabbits,and porcine corneal matrix without corneal epithelium was transplanted onto the left eyes of other 12 New Zealand albino rabbits as control group.The rabbits received keratoplasty were examined using in vivo confocal microscope through focusing(CMTF).The eyeballs were taken off after 2,4 and 8 weeks,the growth and differentiation,expression of cytokeratin 3 (CK3),CK12 and ATP-binding cassette superfamily G memben 2 (ABCG2)of human UC-MSCs were observed by histopathology and immunofluorescence staining.This use of the experimental animals complied with ARVO Statement.Results Digestive human UCMSCs formed round in shape and was large in size.The attached cells displayed long-fusiform shape like fibroblasts.The cultured human UC-MSCs phenotype was CD105+/CD29+/CD44+/CD34-/CD45-and could be induced toward osteoblast differentiation under the appropriate experimental conditions.Human UC-MSCs grew well on the porcine corneal matrix.The corneal grafts survived wcll without rejection till the experiment end in experimental eyes,but the rejection of corneal graft occurred in control eyes.Confocal microscope could observe corneal epithelium-like cells.The corneal epithelium cells showed the positive response for CK3 and CK12 and absent response for ABCG2.Conclusions Human UC-MSCs with porcine corneal matrix can survive,proliferate and differentiate into corneal epithelium-like cells after transplanting onto the corneal stroma of rabbits.This result suggests that human UC-MSCs is able to repair and reconstruct the injured corneal surfaces.

· AIM :To investigate the role of pericytes in growth of retinal microvascular endothelial cells with a co-culture system in order to understand some mechanism of angiogenesis in hypoxia induced retinal neovascular disorders.(RMECs) were isolated by a modified protocol using CD31 coated Dynabeads, and identified by immunocytochemical staining with anti-Factor Ⅷ and CD31 antibodies. Rat retinal pericytes were isolated and characterized by immunofluorescent staining with PDGFR-β; and desmin antibodies. Pericytes and RMECs were cultured in a contact co-culture system both under normoxia and hypoxia by Millicell chamber. RMECs proliferation was evaluated by MTT and cell cycle assay with flow cytometry. RT-PCR was used to detect the alteration of KDR/Flk-1 mRNA level in RMECs under normoxia or hypoxia in the co-culture system.harvested with the modified isolating method. The two cell types were identified by positive Factor Ⅷ, CD31 and PDGFR-β, desmin cytochemical staining respectively.RMECs proliferated significantly under hypoxia from 3 to 9d with a maximal rate on day 6 (24.9%, P ＜ 0.01) by MTT. In the co-culture system, the proliferation of RMECs was inhibited by pericytes. After 6d exposure to hypoxia,the fraction of S-phase RMECs number was greatly increased by 43.9% (P ＜ 0.01). In the co-culture system,RMECs proliferation was inhibited by pericytes through decreasing the fraction of S-phase cell number both under normoxia (3.6%, P＜0.05) and under hypoxia (15.1%,P＜0.01). KDR/Flk-1 mRNA level in single cultured RMECs was shown to increase approximately 1.3-fold when exposed to hypoxia. Compared with single cultured RMECs, co-culture with pericytes could decrease KDR/Flk-1 mRNA by 45.1% (P＜0.05) and 27.7% (P ＜ 0.05) under normoxia and hypoxia condition respectively.pericytes could inhibit proliferation of RMECs under both normoxia and hypoxia. The inhibition effects of pericytes maybe, at least in part, due to downregulation of KDR/Flk-1 of RMECs. These findings confirm that pericytes could be a potential inhibitor in the pathogenesis of retinal neovascularization.

Objective To observe the status of oxidative stress and activity of alkaline phosphatase(ALP) in rats exposed to high fluoride for the different periods and to analyze the effect of fluoride on the activity of ALP and oxidative stress in fluorosis rats. Methods Twenty-four Wistar rats were divided into control and high-fluoride groups according to their body mass, 12 rats in each group. The control group drank tap water(sodium fluoride concentrations < 1 mg/L), and high-fluoride group drank tap water containing sodium fluoride(sodium fluoride concentrations 221 mg/L). On a standard diet and water available ad hbitum, each rat was measured body weight once a week in 1,4,8,12 week. The biochemical techniques were used to test the indicators of oxidative stress including malonaldehyde(MDA), superoxidedismutase(SOD), glutathione peroxidase(GPx), uric acid and activity of ALP in serum of fluorosis rats. Results There was a interaction between fluoride and time in the activity of ALP (F = 4.690,P < 0.05). The activity of ALP was obviously higher in rats exposed to fluoride for 1,12 week [ (19.29± 3.69), (15.72 ± 0.79)kU/L] compared to the control[ (14.08 ± 1.99),(12.91 ± 3.97)kU/L, all P< 0.05] ; the level of MDA was obviously higher in rats exposed to fluoride for 1,4 week [ ( 13.37 ± 4.38 ), ( 11.82 ± 2.08) μmol/L ] compared to the respective control[ (8.75 ± 3.24), (7.42 ± 2.62)μmol/L, all P < 0.05]; difference of SOD and GPx between control and high-fluoride groups was not statistically significant(all P > 0.05); the level of uric acid in serum was significantly higher in high-fluoride group for 1,4 week[ (89.53 ± 13.21 ), (88.47 ± 19.78 )μmol/L] compared to the control [ (77.79 ± 11.43 ), (65.42 ± i 3.42) μ mol/L, all P < 0.05 ], but the level of uric acid showed lower in high-fluoride group for 8,12 week [(67.21 ± 9.44), (73.95 ± 9.52)μmol/L] compared to the control [(77.79 ± 11.43), (65.42 ± 13.42)μmol/L]. Conclusions Effect of overdose fluoride on ALP is time-dependant. On the other hand,overdose fluoride stimulates the status of oxidative stress in a way unrelated to the exposure period.

Objective To observe the level of reduced glutathione(GSH) and oxidized glutathione(GSSG)in a mouse bone cell line MC3T3-E1 cells exposed to fluoride.Methods MTT method was used to detect cell viability of M C3T3-E1 cells exposed to varying concentrations and periods of fluoride [F-concentration:0(control),0.5,1.0,2.0,4.0,8.0,12.0,20.0 mg/L; F-periods:1,2,4 and 10 days].The Xevo TQ MS was employed to test the levels of GSH,GSSG and glutamine (Gln).Results The MC3T3-E1 cell viability was significantly higher in the 2 mg/L group(0.57 ± 0.05) 1 day after the exposure compared to the respective control(0.49 ± 0.03,P ＜0.01); conversely,cell viability was markedly lower in the 8 mg/L(0.49 ± 0.07) and 12 mg/L(0.47 ± 0.09)groups 4 days after the exposure in comparison to the control(0.63 ± 0.06,P ＜ 0.05 or P ＜ 0.01).The cell viability in the 8 mg/L group(1.52 ± 0.29) 10 days after the exposure was significantly higher than that in the control group (0.86 ± 0.23,P ＜ 0.01),however,the value in the 20.0 mg/L group (0.54 ± 0.07) was significantly lower(P ＜0.01).The level of cell GSH decreased significantly in the 20 mg/L groups 2 days[(13.92 ± 4.63)μmol/L]and 10 days [(0.53 ± 0.30)μmol/L]after exposure compared to the respective comtrols [(26.42 ± 3.67),(24.85 ± 5.68)μmol/L,all P ＜ 0.01].The level of cell GSSG markedly increased in the 2 mg/L group 2 days [(1.12 ± 0.62)μ mol/L]and the 8 mg/L group 4 days [(2.13 ± 0.62)μ mol/L]after exposure compared to the controls[(0.55 ± 0.22),(1.46 ± 0.46)μmol/L,all P ＜ 0.05].The similar change was observed in the 8 mg/L group[(2.97 ± 1.30)μmol/L] 10 days after exposure compared to the control [(1.35 ± 0.50)μmol/L,P ＜ 0.05].The level of Glndecreased significantly in the 2 mg/L group[ (62.80 ± 17.4l)μ mol/L] 4 days and in the 8 and 20 mg/L groups 10 days[ (122.26 ± 19.51), (19.38 ± 8.11)μmol/L] after exposure compared to the controls [ (83.28 ±14.32), ( 147.15± 16.95) μmol/L , all P ＜ 0.05 or P ＜ 0.01 ]. Conclusions Fluoride exposure can significantly promote the changes of GSH, GSSG and Gln levels in the osteoblast, thus affecting the intracellular redox equilibrium.

Objective To study the different expressions of receptor activator of nuclear factor-kappa B ligang(RANKL) mRNA in spleens of rats fed with diet of low calcium and high fluoride. Methods A 2× 2×2 factorial design was used and the factors were calcium, fluoride and action time. In the design, 40 Wistar rats [average body mass(118.9±13.5)g] were divided into four groups randomly by weight: control with normal diet (0.790%, calcium), low calcium group with low calcium intake(0.063%, calcium), high fluoride group with normal diet and high fluoride intake(100 mg/L, fluoride) and low calcium and high fluoride group with low calcium and high fluoride intake. After 4 and 8 months, 5 rats of each group were sacrificed and total RNA was extracted from spleen. And the expression levels of RANKL mRNA were determined by reverse transcription polymerase chain reaction (RT-PCR). Results At time of 4 months, the expression level of RANKL mRNA was 0.13± 0.05,0.13± 0.03,0.17±0.02,0.27± 0.05 and at time of 8 months, it was 0.11 ± 0.01,0.16 ± 0.02,0.16± 0.03,0.36 ± 0.07 in control group, low calcium group, high fluoride group, low calcium with high fluoride group, repectively. The factorial design AVONA showed that low calcium and high fluoride had significant effects on RANKL mRNA expression(F = 40.224,56.679, all P < 0.05) while action time had not(F = 2.850, P > 0.05 ). The interactions of low calcium with high fluoride or high fluoride with action time were signifieant(F = 7.247, 18.789, all P < 0.05) while the interaction of high fluoride with action time was not(F = 1.751, P > 0.05). Conclusions Low calcium alone or high fluoride alone or low calcium with high fluoride or low calcium with action time can increase the the RANKL mRNA expression level. High fluoride does not affect the RANKL mRNA level as the action time is prolonged.

Objective To study the role of hematopoietic growth factor(HGF)of placenta chorionic villus in fetal hematopoiesis during embryo ontogeny by observation of the appearance time and the content changes with the fetal growth, which was compared with HGF in cord blood. Methods Thirty embryo villus (2 g each) and 30 cord blood (2 mL each) were collected separately from early pregnant stage(6- 8 weeks), middle pregnant stage(16-22 weeks)and late pregnant stage (37-42 weeks). The levels of HGF were detected by enzyme - linked immunosorbent assay. Results HGF were produced on the early pregnant stage and the content of FL-T3,IL-3 increased gradually.There were significantly differences at different stages(P