食用竹炭粉的急性毒性与致突变性研究

目的:评价食用竹炭粉的急性毒性和致突变性。方法:采用大鼠急性经口毒性试验、Ames试验、大鼠骨髓嗜多染红细胞微核试验和小鼠体内彗星试验,参考经济合作与发展组织(OECD)相关方法进行。急性毒性试验以20 mL/kg进行灌胃;Ames试验设每皿0.008、0.04、0.2、1、5 mg剂量组,另设空白、溶剂、阳性对照;微核试验设2.81、5.62、11.24 g/kg剂量组,另设溶剂、阳性对照;彗星试验设2.81、5.62、11.24 g/kg剂量组,另设溶剂、阳性对照。结果:本实验所用食用竹炭粉(平均粒径为16.596 μm)对雌、雄性SD大鼠的LD₅₀均大于11.24 g/kg;Ames试验、大鼠骨髓嗜多染红细胞微核试验、小鼠体内彗星试验结果均为阴性。结论:微米级食用竹炭粉对大鼠的经口急性毒性属无毒级,对鼠伤寒沙门氏菌组氨酸缺陷型菌株和大、小鼠体细胞无致突变作用。     

Acute and 28-day Sub-acute Oral Toxicity Evaluation of Two Dietary Bamboo Charcoal Powders in Sprague-Dawley Rats

No data were available on the acute oral toxicity, short-term oral toxicity of vegetable carbon in animals. This study was designed to evaluate the safety of two commercially available dietary bamboo charcoal powders(BCP1 and BCP2). The size distribution of the two powders was determined by a Mastersizer 2000 laser particle size analyzer prior to the in vivo safety studies. For the acute toxicity study, a single dose of 11.24 g/kg body weight of BCP1 and BCP2 was given once orally to healthy Sprague-Dawley(SD) rats. Mortality and clinical symptoms were observed and recorded for the first 30 min after treatment, at 4 h post-administration, and then at least once daily for 14 days after administration. In the repeated dose 28-day oral toxicity study, BCP1 and BCP2 were administered orally at doses of 2.81, 5.62, and 11.24 g/kg body weight for 28 days to SD rats. Animals were sacrificed and organs and blood samples were analyzed. Results showed that both BCP1 and BCP2 were micro-sized and various in size. In the acute toxicity and the repeated dose 28-day oral toxicity studies, BCP caused neither mortality nor visible signs of toxicity in rats. No significant differences were found in the relative organ weights or in biochemical parameters in BCP treated groups compared to a control group. No treatment-related histological changes were observed in the organs of these animals. Based on these data, it is concluded that the median lethal dose(LD50) of BCP for both male and female rats is more than 11. 24 g/kg body weight and the no-observed-adverse-effect level(NOAEL) is >11.24 g/kg body weight for 28 days.     

内侧楔形鞋垫矫治成人扁平足的研究进展

成人扁平足导致的足部过度旋前可造成下肢力线改变并影响下肢关节运动功能, 从而引起疼痛并增加运动损伤风险。矫形鞋垫是一种以恢复人体下肢异常力线结构为目的的辅助功能矫形器, 也兼具缓冲减震、增加本体感觉等作用。内侧楔形鞋垫(MWO)能矫正扁平足患者的下肢力线, 改善踝、膝、髋关节运动学参数并缓解下背部疼痛, 因此被广泛应用于矫治扁平足。本研究通过总结分析近年来关于MWO矫治成人扁平足的文献报道, 发现合理应用MWO可改善扁平足患者足部过度旋前, 从而影响下肢各关节运动及下肢肌肉活动, 对缓解扁平足人群在特定运动时疼痛及预防运动损伤具有积极作用。     

上海市学龄儿童足弓指数及扁平足的流行病学研究

调查上海市学龄期(7~12岁)儿童足弓指数(arch index,AI)及扁平足的流行状况,及其与儿童年龄、性别、体质量指数(BMI)、左右侧分布的关系,为预防扁平足提供参考.方法 对上海市10所中小学校学龄期儿童(3 226名)应用三维足部测量仪器测量双侧脚长、内侧弓高、AI、弓高弓长比(arch height ratio,AHR)等足部参数,并进行统计分析.结果 上海市7~12岁儿童AI为(0.27±0.05),AHR为(3.02± 1.89),总体扁平足发生率为56.1%,7岁时为72.6%,12岁时降至37.9%;男童为62.9%,女童为47.8%.男童扁平足发生率高于女童(OR=1.81,95%CI=1.57~2.10),该风险大小与年龄无关,每个年龄段男童发生扁平足的风险始终高于女童.对7~8岁儿童,超重或肥胖与扁平足发生无相关;对9~12岁儿童,超重或肥胖与扁平足有相关,且OR值随着年龄的增加而增加,9岁时为1.44(95%CI=1.03~2.03),12岁时为2.96(95%CI=1.68~5.23).扁平足发生在左或右侧差异无统计学意义(x2=0.95,P=0.33).结论 7~12岁儿童的AI及扁平足发生率随年龄增加而降低,男童发生扁平足的风险更高.9岁及以上生长发育期儿童超重和肥胖者发生扁平足的风险更高.对扁平足应做到早发现、早干预.