Objective To study the effects of fluoride on longitudinal growth and pathological changes of cultured rat metatarsal bone rudiments.Methods Twenty-four neonatal SD rats were divided into four groups according to the random number table,then the second,third and fourth metatarsal bone rudiments were surgically isolated.The left metatarsal bone rudiments were cultured in α-MEM without F-as control group and the right metatarsal bone rudiments from the same rat were cultured in α-MEM with 1 × 10-7,1 × 10-6,1 × 10-5 and 1 × 10-4 mol/L F-.The length and width of the mineralized area of metatarsal were measured on day 0,day 1,day 4 and day 7,respectively,and the pathological changes of metatarsal bone rudiments were observed by the routinely paraffin-embedded sections method on day 7.Results On day 7,the length of the mineralized area was significantly lower of right metatarsal bone [(240.5 ± 139.3)μm] than the left metatarsal bone [(394.1 ± 173.9)μm,t =4.37,P ＜ 0.01] in the 1 × 10-4 mol/L F-group,but the width of the mineralized area [(239.9 ± 119.4)μm] was not different significantly compared to the left metatarsal bone [(223.3 ± 99.9)μm,t =0.44,P ＞ 0.05].The relative vertical growth rate of the mineralized area on day 4 was significantly lower of right metatarsal bone [(2.43 ± 1.44)％] than left metatarsal bone [(8.34 ± 1.74)％,t =3.21,P ＜ 0.01] in 1 × 10-4 mol/L F-group,and the difference was also significant on day 7 [(16.16 ± 2.87)％ vs.(26.52 ± 4.46)％,t =3.13,P ＜ 0.01].Toluidine blue staining results showed that the thickness of cartilage cells of proliferation and hypertrophic layers was significantly lower of right metatarsal bone [(111.33 ± 27.29),(125.33 ± 30.08)μm] than left metatarsal bone [(127.33 ± 38.36),(160.50 ± 42.73)μm,t =4.82,5.81,all P ＜ 0.01] in 1 × 104 mol/L F-group.The ratio of proliferative and hypertrophic layers was significantly higher of right metatarsal bone (0.93 ± 0.36) than left metatarsal bone (0.83 ± 0.32,t =4.42,P ＜ 0.01) in 1 × 10-4 mol/L F-group.Conclusions Our findings indicate that excessive fluoride could cause longitudinal bone growth inhibition.Such growth inhibition is mediated by decreased chondrocyte proliferation and differentiation and the disproportion of proliferation and differentiation.

The relatively high abundance of geochemical elements such as Nb, Zr, Y and other elements shows serious interferences in the determination of trace silver in geochemical samples by inductively coupled plasma-mass spectrometry ( ICP-MS) . Thus it will lead to large deviation in the determination of geochemical samples without separation and enrichment. The traditional emission spectrum or graphite furnace atomic absorption method is only single-element analysis to the silver and with bad sample representativeness. In this study, load diphenylthiourea ( DPTU) foam selective enrichment was used for the separation of Au and Ag from other interfering elements in geological samples, and thiourea liberation-ICP-MS method was developed for the simultaneous determination of Au and Ag. The samples were first decomposed by 1:1 aqua regia. After addition of 50 mL of water, the samples were adsorbed under oscillation for 30 min at 20℃. The detection limits of the Au and Ag were 0. 02 ng/g and 0. 007μg/g, respectively. The proposed method was successfully applied to the determination of Au and Ag in eight national standard materials.

Tumor angiogenesis is the important pathophysiological characteristics of human glioma.The treatment of tumor angiogenesis is currently a hot research topic.This article reviewed the domestic and international research on angiogenesis of glioma,included animal models,cellular mechanisms,regulatory factors,signaling pathways,antiangiogenic drugs,and proteomics regarding glioma angiogenesis to clarify the current status of research and clinical treatment,providing reference for further study on angiogenesis of glioma,and discovery of novel biomarkers of tumor angiogenesis and therapeutic targets.

Autophagy is a highly conserved mechanism for material degradation and recycling in eukaryote cells, and plays important roles in growth, development, stress tolerance and immune responses. ATG10 plays a key role in autophagosome formation. To understand the function of ATG10 in soybean, two homologous GmATG10 genes, namely GmATG10a and GmATG10b, were silenced simultaneously by bean pod mottle virus (BPMV) induced gene silencing. The carbon starvation induced by dark treatment and Western blotting analysis of GmATG8 accumulation level indicated that concurrent silencing GmATG10a/10b resulted in the impairment of autophagy in soybean; disease resistance and kinase assays demonstrated that GmATG10a/10b participated in the immune responses by negatively regulating the activation of GmMPK3/6, indicating that GmATG10a/10b plays a negative regulatory role in immune response in soybean.
Soybeans/genetics* ; Immunity