脐血铅浓度与新生儿端粒长度的相关性.doc

1、脐血铅浓度与新生儿端粒长度的相关性摘要 目的 研究脐血铅浓度与新生儿端粒长度的相关性。 方法 收集 2010 年 7 月2013 年 4 月青岛市市立医院产科孕期无急慢性疾病的足月顺产儿脐血 78 例，原子吸收光谱法测定脐血铅浓度，测得脐血铅浓度在 1189?g/L范围。将 78 例脐血分成 A、B 、C 三组：A 组脐血铅浓度60?g/L，共 12 例。采用全血提取基因组法提取脐血 DNA，荧光定量 PCR 法测基因组 DNA 的端粒长度。各组间比较采用单因素方差分析，两两比较采用 q 检验，相关性采用Spearman 相关性研究。 结果 A 组端粒长度为：1.1520.716，B 组端粒长

2、度为 0.6140.407，C 组端粒长度为 0.5460.339，从 A 组到 C 组端粒长度逐渐缩短，且差异有统计学意义（F=4.895，P0.05 ） 。三组端粒长度与脐血铅浓度呈负相关（r=-0.461，P100?g/L.Lead does not have any normal physiological functions in the human body，but lead can affect a variety of system functions and is not easily removed after it enters the body. Without any

3、 normal physiological functions to in human body，its ideal blood lead concentrations should be 0. As a result， some developed countries lowered the lower limit defining concentration for lead poisoning， setting the blood lead concentrations 60?g/L as lead poisoning. For the fetus，lead is mainly tran

4、sferred by the mother during pregnancy through the umbilical cord and placental barrier.Therefore，this study collected umbilical cord blood and different of umbilical cord blood lead concentrations were divided into three groups： group A cord blood lead concentrations 60?g/L. This allowed us to stud

5、y the effect of umbilical cord blood lead to neonatal telomere length.From these result we determined that with the rise of umbilical cord blood lead concentration，the telomere length shorten progressively，and telomere length and umbilical cord blood lead concentrations correlated negatively（r=-0.46

6、1，P 30 ?g/L， telomere length would seriously be affected and cause telomere shortening.The latest study suggested that the two main factors19for telomere shortening were the incomplete copy of cell division telomere end and the damage of telomere DNA. Under normal condition， these two factors could

7、be recover telomere length under the action of telomere and the binding of telomerase and telomere protein. But when there was lead exposure， telomere shortening could not be restored， telomerase and telomere binding protein function was affected by lead and caused the telomere length shortening. Ac

8、cordingly we conclude，umbilical cord blood lead can shorten the neonatal telomere length；with increasing blood lead concentration，the telomere length of neonate are progressively shortened；and lead may be interfere with telomere length and make it short by influencing the role of telomerase and telo

9、mere binding protein. In summary，umbilical cord blood lead can shorten the length of neonatal telomere and different neonatal umbilical cord blood lead concentrations are associated with different changes to telomere length. When umbilical cord blood lead exceeds 30?g/L，the newborn telomere length w

10、ill be affected seriously， and the higher the concentration，the more serious the impact on neonatal telomere length. The length of the telomere shortening can also increase the incidence of a number of diseases，such as Coronary Heart Disease， Hypertension，Cancer ，Diabetes，Obstructive Sleep Apnea Syn

11、drome， and a variety of autoimmune diseases.It also can affect childrens mental development.Therefore，we should pay more attention to the influence of maternal lead exposure during pregnancy on neonatal growth and development.The influence of blood lead on telomere length may be by affected telomerase and telomere binding protein function that makes the telomere length shortened， however the exact mechanism remains to be further studied.