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Background A large number of studies on fluoride-induced systemic bone damage have been reported previously, but there is little understanding of the characteristics of fluoride accumulation in jawbone. Jawbone is homologous to the other bone tissues in the body, and is an indispensable and important frame structure in the oral cavity. Objective To study fluoride accumulation and its change trends in teeth, jawbone, and femur of SD rats with chronic drinking-water-borne fluorosis. Methods A total of 144 three-week-old SD rats, half male and half female, were randomly divided into two groups, a normal control group and a fluoride group. The rats in the normal controlgroup drank purified water disinfected and filtered from Guizhou, and the water contained 0.08 mg·kg−1 fluoride which was lower than the national water quality standard at 1 mg·kg−1. The rats in the fluoride group were fed with sodium fluoride (NaF) solution with a concentration of 150 mg·L−1. At 3, 5 and 7 months of the fluoride exposure, the levels of fluoride in urine, blood, teeth, jawbone, and femur were measured by fluoride ion electrode method. Results There was no sex difference in fluoride content in different biological samples of rats in the fluoride group and the normal control group (all P>0.05). After 3 months of fluoride exposure, the rats in the fluoride group showed dental fluorosis of grade II, and higher levels of fluoride ion in blood and urine than the normal control group (all P<0.05), indicating that the rat model of fluoride drinking-water-borne chronic fluorosis was successfully replicated. In the normal control group, the levels of fluoride in femur remained stable; at the end of 3 months, the levels of fluoride in jawbone and teeth were (1097.36±470.34) and (453.09±173.43) mg·kg−1 respectively, and at the end of 7 months, the levels of fluoride in jawbone and teeth were (2113.18±634.49) and (1604.80±160.43) mg·kg−1 respectively. Both jawbone and teeth showed a positive temporal effect of increasing fluoride accumulation (P<0.05). After continuous fluoride feeding, the fluoride levels in jawbone, teeth, and femur of rats in the fluoride group were (3145.02±765.82), (1550.20±77.73), and (3640.55±699.42) mg·kg−1 after 3 months, and (8420.36±1728.56), (4702.08±1417.06), and (6091.99±1384.97) mg·kg−1 after 7 months. The three kinds of hard tissues all showed a positive temporal effect of increasing fluoride accumulation (P<0.05), and the cumulative increas was large than that in the normal control group. Among them, jawbone fluorine increased most. At the end of 5 months, the levels of fluoride in jawbone, femur, and teeth were (6485.02±2141.98), (4914.99±1529.41), and (3365.21±1462.27) mg·kg−1 respectively, and the levels of fluoride in jawbone was much higher than those in femur and teeth (P<0.05). Conclusion Hard tissues such as bones and teeth are fluorine sensitive tissues. Compared with femur, jawbone showed significantly high fluoride accumulation, while teeth show relatively lagging fluoride accumulation.
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Objective:To observe the effect of fluoride on growth and development of bone microstructure of rats condyle subchondral bone (RCSB).Methods:Forty two 3-week-old SD rats (half male and half female) were fed adaptively for 1 week, and 3 females and 3 males were sacrificed and recorded as 0 month. The remaining rats were randomly divided into control group ( n = 18) and fluoride exposed group ( n = 18) according to their body weight (55 - 70 g), half male and half female. The fluoride exposed group was fed with 150 mg/L sodium fluoride (NaF) aqueous solution, and the control group was fed with tap water. The two groups of experimental animals were sacrificed at 3, 5 and 7 month, respectively, 6 rats in each group, half male and half female. The right mandibular condyle was separated, and Micro CT scanning was performed to detect the microstructure parameters of RCSB. Results:In fluoride exposed group (3 month), bone surface/tissue volume (BS/TV), bone surface/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), structure model index (SMI), connectivity, connectivity density (Conn.D) and total porosity of female rats were significantly different from those of male rats ( t = - 5.10, - 5.58, 4.52, - 4.32, - 4.03, - 2.81, - 6.71, - 3.32, P < 0.05). There was no significant difference in each index between female and male rats in fluoride exposed group (5, 7 month, P > 0.05). Conclusion:In chronic fluorine exposure bone environment, the RCSB bone microarchitecture of male and female rats is different with time, showing the tendency of fluoride injury that the bone changes of female rats are slowed and the bone changes of male rats are active.
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Objective To evaluate the efficacy and safety of combination therapy of oxaliplatin and S-1 vs oxaliplatin and docetaxel for advanced gastric cancer (AGC)patients.Methods From April 201 1 to Janu-ary 201 3,62 cases of AGC were collected in the Fifth People′s Hospital of Qinghai Province.All cases were randomly divided into group A (31 cases)and B (31 cases)by random number table.In group A,oxaliplatin plus S-1 was administered,and in group B,oxaliplatin plus docetaxel was applied.The response rate (RR), time of diseases controlled rate (DCR),progression-free survival (PFS),overall survival (OS)and adverse reactions of the two groups were observed and compared.Results There were no statistically differences between group A and group B in RR (48.4% vs 54.8%),DCR (67.7% vs 77.4%),mPFS (5.4 months vs 6.2 months),mOS (9.0 months vs 9.8 months),and the statistical values were as follows:χ2 =0.26,P =0.71 1 ;χ2 =0.73,P =0.393;χ2 =0.51 ,P =0.473;χ2 =0.03,P =0.829.The incidence of degrees Ⅰ-Ⅱperipheral neuropathy (9.7% vs 22.6%),nausea and vomiting (1 2.9% vs 32.3%)in group A were signifi-cantly lower than those in group B (χ2 =5.78,P =0.002;χ2 =4.63,P =0.01 6).Conclusion Both the two chemotherapies are similar in therapeutic effect for patients with AGC.Oxaliplatin plus S-1 treatment may be better than oxaliplatin plus docetaxel in the tolerance of patients.