燃煤型氟中毒大鼠诱导型一氧化氮合酶蛋白表达、血清睾酮与生精细胞凋亡的相关性研究

目的:研究燃煤型氟中毒大鼠睾丸组织诱导型一氧化氮合酶(iNOS)蛋白表达、血清睾酮(T)与生精细胞凋亡的相互关系,探索燃煤型氟中毒对睾丸生殖功能损伤的机制。方法:将40只雄性SD大鼠随机分为4组:对照组、低氟组、中氟组、高氟组。各染毒组喂饲含不同比例的燃煤型氟中毒病区煤烘玉米的饲料,建立雄性大鼠燃煤型氟中毒模型。分别于染毒4和6个月后以股动脉放血法处死大鼠,各时间点每组处死大鼠5只。采用RIA法测定大鼠血清T水平;检测血清中超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量、iNOS活性;原位缺口末端标记(TUNEL)法检测大鼠睾丸生精细胞凋亡情况并计算凋亡指数(AI);免疫组织化学染色SP法观察iNOS蛋白表达的变化。结果:成功建立雄性大鼠氟中毒模型。大鼠血清T水平在4和6个月时低氟组[(28.37±0.19)nmol/L、(14.68±0.36)nmol/L]、中氟组[(25.85±0.23)nmol/L、(9.08±0.31)nmol/L]、高氟组[(23.63±0.29)nmol/L、(4.89±0.54)nmol/L]较对照组[(29.77±0.43)nmol/L、(29.97±0.36)nmol/L]均降低(P0.05或P0.01),且各染氟组间差异有统计学意义(P0.05或P0.01)。睾丸生精细胞AI在4和6个月时低氟组(8.83±1.64、10.40±2.70)、中氟组(17.24±3.96、22.20±3.96)、高氟组(44.21±7.85、49.60±4.77)较对照组(0.46±0.11、0.54±0.11)升高(P均0.01),且各染氟组间差异有统计学意义(P0.05或P0.01)。睾丸组织iNOS蛋白表达的OD值在4和6个月时低氟组(0.073 3±0.008 5、0.108 4±0.012 6)、中氟组(0.142 5±0.027 2、0.207 7±0.020 4)、高氟组(0.527 5±0.079 1、0.717 3±0.065 6)较对照组(0.001 3±0.000 2、0.001 6±0.000 1)增加(P0.05或0.01),且各染氟组间差异有统计学意义(P0.05或P0.01)。iNOS蛋白表达量与生精细胞AI呈正相关(r=0.962,P0.01);血清T水平与生精细胞AI呈负相关(r=-0.744,P0.01)。结论:血清T水平改变和睾丸组织iNOS蛋白表达调控改变可能参与燃煤型氟中毒对睾丸生殖功能损害的过程。     

安阳市第二次地氟病调查

目的分析安阳市地氟病现状,为制定地氟病防治策略和规划提供依据。方法开展安阳市第二次地氟病调查,调查全市10个县（市、区）居民饮水含氟量、儿童氟斑牙、成人氟骨症患病情况。结果共调查乡镇108个,自然村3723个,发现水氟超标自然村454个,占12.1%;儿童氟斑牙患病率超过30%的自然村425个,儿童氟斑牙患病率43.69%,在4个县共发现氟骨症患者1157人。结论安阳市地氟病分布广泛,地氟病危害仍然较为严重。     

氟对大鼠肝脏氧化应激及超微结构的影响

目的:研究氟对大鼠肝脏氧化应激及超微结构的影响.方法:在饮水中加入不同剂量的氟化钠(0,50,100和150 mg/L)喂饲大鼠3个月后,测定肝脏丙二醛(MDA)含量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性,并用透射电镜观察肝脏超微结构的改变.结果:与对照组比较,染氟组大鼠肝脏MDA含量升高,SOD、GSH-Px活性下降.透射电镜下肝细胞染色质边集于核膜下,线粒体肿胀,嵴断裂或消失,内质网扩张,胞质内多见脂滴.结论:过量氟使大鼠肝脏处于氧化应激状态,损伤细胞膜性结构和DNA,造成肝脏损伤.     

湖南省燃煤污染型氟中毒重点病区调查结果分析

目的 了解湖南省近20年燃煤污染型氟中毒流行规律及病区变化情况。方法 抽查3个重病区县（市），分别对病区村和非病区村的尿、水、食物氟含量测定，并进行儿童氟斑牙调查。结果 病区村8～12岁氟斑牙患病率66．36%，非病区氟斑牙患病率37．39％，辣椒样氟含量均值30．22mg／kg，尿氟含量中位数1．11mg／L（最大值为17．97mg／L）。7个原非病区中5个已构成病区村。结论 调查县燃煤污染型氟中毒病区病情流行较为严重，病区呈扩大之势，氟源除室内空气污染外，还与食物（特别是辣椒等）受污染有关。     

燃煤型氟骨症早期大鼠血清PTH、CT的变化

目的研究燃煤型氟骨症早期血清甲状旁腺激素(PTH)、降钙素(CT)的变化。方法将SD大鼠随机分为6组:对照、低氟、中氟加营养、中氟、高氟加营养、高氟组,每组34只,雌雄各半。各染毒组喂饲含不同比例的燃煤型病区煤烘玉米的饲料复制氟中毒动物模型。分2批以股动脉放血法处死动物,检查氟斑牙,测尿、骨、肾氟,骨密度(BMD),骨Ca、尿Ca,血清PTH、CT。结果(1)建成氟中毒动物模型:各染毒组均出现氟中毒,对照组正常。中毒严重程度随氟剂量增加而加重;氟剂量相同时,营养好,中毒程度轻。(2)燃煤型氟中毒对骨代谢相关激素的影响:高氟组血清PTH后期高于早期,差异有统计学意义(P<0.01)。说明染氟大鼠成骨活动增强,该指标变化较晚。血清CT各组早期无变化,后期低氟组和中营组升高,差异有统计学意义(P<0.05或0.01);低氟组高于高氟组,差异有统计学意义(P<0.05)。结论(1)骨转换活跃可能是燃煤型氟中毒骨病变发生发展的一个重要环节并且早期以成骨活跃为主;(2)尚不能认为血清PTH、CT是反映燃煤型氟骨症病情的早期指标;(3)降低摄氟量及改善营养状况,可缓解氟中毒病情。     

Reversal of fluorosis in children

Large populations consume fluoride-contaminated water, especially in developing countries. The toxic effects of fluorosis take three forms: clinical, skeletal and dental. Research thus far indicates that the manifestations of fluorosis are irreversible. However, it has been observed that the ingestion of calcium, vitamin C or vitamin D, individually, is effective in protection from fluoride toxicity to a certain extent. Therefore, a double blind control trial was conducted to examine the effect of a combination of calcium, vitamin D₃ and ascorbic acid supplementation in fluorosis-affected children. In the present study, 25 children were selected from an area consuming water containing 4.5 p.p.m. of fluoride, All the children were in the age group 6–12 years and weighed 18–30 kg. They were graded for clinical, radiological and dental fluorosis and relevant biochemical parameters. Grade I skeletal fluorosis and all grades of the manifestation of dental and clinical fluorosis were observed. The children were given ascorbic acid, calcium and vitamin D₃ well below the toxic dosages in a double blind manner using lactose as a placebo. Follow up revealed a significant improvement in dental, clinical and skeletal fluorosis and relevant biochemical parameters in these children. Thus, the study indicated that fluorosis can be reversed, at least in children, by a therapeutic regimen that is fairly cheap, simple and easily available and without any side effects.     

氟暴露对机体骨外系统损伤的研究(二)──氟致鼻咽、牙疾患的临床分析

为探讨氟对机体的影响，提供早期实用的健康监护指标，对氟作业工人骨外系统损伤（鼻咽、牙疾患）进行了调查研究。结果表明，氟作业工人鼻咽、牙疾患较为明显，并具有鼻炎、牙周炎发病高的特点，提示为工业性氟病早期表现之一。     

The ultrastructure of fluorosed human dental enamel

abstract — More than 80 specimens of enamel from 20 ground sections of eight teeth showing severe dental fluorosis have been examined in the transmission electron microscope. The study has shown that the prisms have normal size and form, but are surrounded by large periprismatic gaps. The individual crystals commonly appear in cross sections as regular, flattened hexagons with an average width of 91 nm and average thickness of 45 nm. Particularly in the tail regions and at prism peripheries, extensive intercrystalline spaces were found. The crystal lattice demonstrated a spacing of 0.82 nm. Demineralization of thin sections with PTA showed a preferential dissolution of the crystal centers. Based on the ultra-structural observations it is proposed that the hypomineralized regions of fluorosed enamel are produced by an arrest of enamel maturation, possibly due to toxic damage to the ameloblasts in the absorptive or maturative phase of their life cycle.     

Comparison of dental fluorosis and caries in primary teeth of preschool-children living in arid high and low fluoride villages

Abstract The aim of this study was to determine the degree of fluorosis in the primary dentition and the accompanying caries patterns in groups of preschool-children in high and low fluoride areas. Among 331 coloured children, aged 1 -5 years, living in an area with water F concentrations ranging from 2.2 to 4.1 parts/10⁶, 82% were caries free and the dmft values ranged from 0 to 15 with a mean dmft of 0.8 ± 2.1. Varying degrees of fluorosis in the primary teeth were present in 50.6% of the children. In 177 coloured children of similar ages from an adjacent area with 0.2 parts/10⁶ F in the drinking water the dmft values ranged from 0 to 20 with a mean dmft of 5.4 ± 5.8. Only 28% of the children were caries free. None of the children in this area had fluorosis. The caries prevalence was significantly higher in the low fluoride area than in the high fluoride area. The degree of fluorosis found in the primary dentition in the children from the high fluoride area was higher than had been anticipated and was accompanied by a very low caries prevalence.