Two types of intraoral distribution of fluorotic enamel

Abstract Different distributions of fluorotic dental enamel within the dentition have been described in the literature. This report describes two patterns of intraoral distribution. In nine Tanzanian low fluorosis communities with a prevalence of pitting fluorosis of less than 2% and in live moderate fluorosis communities with a prevalence of pitting fluorosis of 16–59%, incisors and first molars were the least affected teeth. In four high fluorosis communities with a prevalence of pitting fluorosis of 86–97%, maxillary incisors exhibited lower Thylstrup-Fejerskov Index values than the maxillary canines, premolars and molars. The mandibular teeth exhibited increasing Thylstrup-Fejerskov Index values from the anterior to the posterior region. The curves presenting the intraoral distribution of the severity of dental fluorosis corresponded with the curve presenting the completion time of primary enamel formation of the various tooth types, with the exception of the first molars in high fluorosis communities. The similarity of the curves suggests that the later in life enamel is completed, the higher is the severity of dental fluorosis. This relation seems to be explained by the prevailing feeding and dietary habits, which result in minimal intake of fluoride in the first 18 months of life during breastfeeding, followed by increasing fluoride ingestion in the following years through consumption of tea, seafish and F-containing magadi salt.     

恩施市地方性氟中毒病区氟源初步调查

了解恩施市地方性氟中毒病区高氟来源,为地方性氟中毒病防治提供科学依据。方法：应用氟离子选择电极法分析新塘和红土两病区饮水、空气、煤及食物中氟含量。结果：饮水氟含量平均值为０．１６ｍｇ／Ｌ,低于国家饮用水氟标准;室内空气中氟含量平均值为 ０．０７８ｍｇ／ｍ３,超过国家空气氟标准;煤氟含量平均值为 ５３．９７ｍｇ／ｋｇ;食物氟水平普遍高于以燃柴为主的非氟病区,两病区属燃煤型地方性氟中毒病区。     

饮水型氟病区人体总摄氟量与发病关系的研究

通过对丹江口市饮水型型地氟病区两个村改水前后环境氟含量,人体总摄氟量及８－１２岁儿童氟玉牙发病率的调查与相关分析,发现改水后人群总摄氟量中食中氟所占比例约为４０％－５０％,总摄氟量与８－１２岁儿童氟斑牙率,氟斑牙指数,尿氟均呈正相关,总一比单纯水氟或粮食氟更能反映出人群总体氟水平。     

广东省梅州市饮水型氟中毒病区病情现状调查分析

目的掌握梅州市辖区内饮水型氟中毒的病情及改水降氟后效果，为防治饮水型氟中毒提供科学依据。方法梅州市的6个地氟病区县（市），采用普查和抽样调查相结合，对调查县（市）氟病区村8～12岁儿童氟斑牙采用Dean氏法检查，饮水氟、儿童尿氟均采用氟离子选择电极法进行检测。结果调查的6个县38个乡镇115个病区村中，儿童氟斑牙总患病率为21．99％，儿童尿氟几何均值为1．45mg／L，饮水氟范围为0．10～2．10mg／L。结论梅州市饮水型氟中毒病区的病情，通过改水降氟已经得到有效控制，但还有9个病区村的儿童氟斑牙患病率未达到控制病区标准；个别病区村的改水设施存在着管理不善问题。     

LS8 cell apoptosis induced by NaF through p-ERK and p-JNK – a mechanism study of dental fluorosis

Objective: To investigate the possible biological mechanism of dental fluorosis at a molecular level.

Material and methods: Cultured LS8 were incubated with serum-free medium containing selected concentrations of NaF (0?～?2?mM) for either 24 or 48?h. Subcellular microanatomy was characterized using TEM; meanwhile, selected biomolecules were analysed using various biochemistry techniques. Transient transfection was used to modulate a molecular pathway for apoptosis.

Results: Apoptosis of LS8 was induced by NaF treatment that showed both time and concentration dependency. The activity of caspase-3, -8, -9 was found to be increased with NaF in a dose-dependent manner. Western blot revealed that the protein expression of p-ERK and p-JNK were decreased, while the expression of p-P38 was increased. Inhibition of the p-ERK and p-JNK pathways resulted in a similar decrease for caspase-3.

Conclusion: During NaF-induced apoptosis of LS8, p-ERK and p-JNK were closely associated with induction of apoptosis, which might be a mechanism of dental fluorosis.     

广东省韶关市饮水型氟中毒现状调查

目的了解改水后广东省韶关市所辖乐昌市和始兴县地方性氟中毒(地氟病)病区病情现状。方法采用流行病学调查方法,8～12岁儿童氟斑牙采用Deans法分度诊断；饮水氟测定采用离子选择电极法。结果乐昌市廊田镇岩前村委的5个村饮冷泉水的水氟均值1．63mg/L,8～12岁儿童氟斑牙检出率44．45%,16岁以上人群氟骨症临床检出率3．80%,氟骨症X线临床检出率8．0%。始兴县的6个病区村改水后饮水氟范围在0．23～0．59mg/L,8～12岁儿童氟斑牙总检出率8．61%；罗坝镇廖屋村饮水氟均值为2．10 mg/L,8～12岁儿童氟斑牙检出率68．75%。结论乐昌市廊田镇岩前村委5个饮用冷泉水的自然村为饮水型氟中毒轻病区；始兴县罗坝镇廖屋村还是饮水型地氟病病区,需要改换饮用水源,才能控制地氟病的流行。     

云南昭通燃煤中砷的释放规律及其环境效应研究

目的探讨燃煤型氟中毒病区燃煤中砷的实际燃烧释放规律及其环境效应。方法于2005—2010年,在云南昭通系统采集了24户农户的煤、拌煤粘土、煤泥、煤渣以及新鲜玉米和烘烤玉米样品进行砷含量的检测,并计算煤泥中砷元素的燃烧释放量及释放率,分析了煤泥中砷释放量与烘烤玉米中砷增加量的关系。结果煤中砷含量为0.72~14.35 mg/kg,中位数为3.92 mg/kg;拌煤粘土中砷含量为1.66~66.59 mg/kg,中位数为17.22 mg/kg;煤泥中砷含量为1.81~29.52 mg/kg,中位数为7.79 mg/kg;煤泥中砷的释放量为0.09~22.47 mg/kg,中位数为2.00 mg/kg;煤泥中砷的释放率为0.92%~76.10%,中位数为31.76%;新鲜玉米中的砷含量为未检出~0.03 mg/kg,中位数为0.02 mg/kg,远低于GB 2762—2005《食品中污染物限量》中砷限量(0.2 mg/kg);烘烤玉米中的砷含量为未检出~0.34 mg/kg,中位数为0.09 mg/kg,与新鲜玉米相比有了大幅增加,超标率仅为23.8%。粘土与煤泥中砷释放量呈正相关(P=0.001),而砷释放量与烘烤玉米砷增加量间无统计学相关性(P=0.604)。结论拌煤粘土是燃煤中砷污染物释放的重要来源。烘烤玉米中砷污染程度不仅与煤泥中砷释放量有关,而且受到烤房条件、敞炉结构、烘烤时间等多种因素的影响。     

慢性氟中毒小鼠脊髓病理学改变

本文对120只纯系巴氏小白鼠进行了不同时间、不同浓度氟水饲养后,饮高氟水小鼠脊髓病理改变如下,神经细胞空泡变性;神经细胞Nissl氏小体溶解、减少或消失;神经细胞固缩改变;噬神经细胞现象;神经细胞及其间质水肿;神经细胞数量减少和脊髓出血。病理改变与饮高氟水浓度有关,与饮高氟水时间关系更密切。所有实验小鼠脊髓神经髓鞘均未见异常。从而论证氟中毒可造成脊髓的直接损害,而且主要是对灰质的损害。对脊髓血运的影响间接造成脊髓损害可能也是病理因素之一。     

山东省地方性氟中毒流行现状

目的查清山东省地方性氟中毒的病区分布和危害程度。方法按照“山东省地方性氟中毒防治工作现状调查方案”的要求，对原地方性氟中毒病区村和疑似病村进行流行病学调查。结果全省地方性氟中毒病区分布在17个市113个县(市、区)Il656个村，病区人12I为979万余人，其中轻病村7102个人口601万余人，中病村3840个人口320万余人，重病村714个人12157万余人。比1987年前调查统计的结果增加了3620个病村和327万余人。结论山东省地方性氟中毒病区范围进一步扩大，危害仍十分严重。