驱铅病人尿中铅含量的原子吸收法测定

尿铅的测定目前普遍采用冷消化—双硫腙比色法、热消化—双硫腙比色法和阳极溶出伏安法。这些方法对于一般的晨尿类样品的铅含量的测定具有灵敏度高和检测限低等优点。但是用这些方法来测定驱铅病人尿中的铅含量时,常常因样品中铅的浓度太高,超出了工作曲线的线性范围,难以准确计量,可能引起了较大的测量误差。考虑到火焰原子分光光度法的测定铅的线性范围较宽,笔者用它直接进样测定驱铅尿样中铅含量,具有快速、操作简便、结果准确、省时省力等优点。1 实验部分     

妊娠期补钙对铅暴露胎儿的影响

妊娠期低水平铅暴露危害母婴的健康,铅可通过胎盘进入胎儿体内影响生长发育。钙剂干预可降低孕期铅暴露水平及减轻铅毒性。孕期进行营养干预对预防胎儿铅毒性很大的临床应用价值。     

妊娠期补钙对铅暴露胎儿的影响

妊娠期低水平铅暴露危害母婴的健康，铅可通过胎盘进入胎儿体内影响生长发育。钙剂干预可降低孕期铅暴露水平及减轻铅毒性。孕期进行营养干预对预防胎儿铅毒性有很大的临床应用价值     

孕期补钙预防高危孕妇妊娠期高血压疾病的临床观察

目的探讨孕期补钙对预防高危孕妇妊娠期高血压疾病和胎儿生长受限(fetal growth restriction,FGR)的效果。方法选择2009年5月至2011年4月,在深圳市光明新区人民医院门诊行产检并有妊娠期高血压疾病高危因素的孕妇162例,随机分为补钙组(86例)及对照组(76例)。补钙组自孕20～27周起口服葡萄糖酸钙片1.5g/d,连续口服至分娩,对照组未补钙。两组均在进入研究时、晚孕期和临产时检测血清钙,观察妊娠期高血压疾病及胎儿生长受限发病情况。结果补钙组晚孕期和产时血清钙高于补钙前(P<0.05);补钙组妊娠期高血压疾病和FGR发生率明显低于对照组(P<0.05)。结论孕期补钙可有效预防妊娠期高血压疾病的发生,保障胎儿健康发育。     

妊娠期补钙200例的临床效果观察

目的 观察孕期应用钙剂对预防妊娠期高血压疾病(PIH)及胎儿生长受限(FGR)的效果.方法 选择200例孕20～35周初孕妇,随机分为补钙组100例和对照组tOO例.补钙组口服乐力钙.时照组不服药物.两组均每4周测定孕妇血钙,观察PIH及FGR发病情况.结果 补钙组的血清钙明显高于对照组,且PIH和FGll发生率明显低...     

Uncertain effects of folic acid on disorders other than neural-tube defects

Periconceptional supplemention with folic acid prevents neural-tube defects in infants. However, contrary to expectations, clinical trials found no beneficial effect of folic acid on the recurrence of cardiovascular disease. Trial evidence on folic acid and cognitive decline or dementia is scarce, though observational studies suggest that high folate intake may prevent these disorders. In contrast, animal studies suggest that high doses of folic acid enhance the growth of existing tumours. However, recent clinical trials failed to show significant effects of folic acid on cancer incidence and mortality. There are also speculations that folic-acid fortification may increase the number of newborns with the thermolabile variant of methylene tetrahydrofolate reductase. There appears to be little evidence that folic-acid supplementation may mask vitamin-B12 deficiency. In view of these controversies, it is unlikely that The Netherlands will mandate folic-acid fortification of staple foods in the near future. Therefore, women who are planning a pregnancy should be urged to take folic-acid supplements.     

增补叶酸预防神经管缺陷项目实施现状

叶酸对健康的影响,尤其是妊娠并发症和先天畸形的产生,一直受到广泛关注。本文对叶酸的作用、叶酸与神经管缺陷（NTDs）的关系以及育龄妇女增补叶酸预防NTDs的研究现状进行综述,分析实施现况存在的问题,为提高叶酸预防NTDs措施实施的广泛性和有效性提供参考依据。     

妇女妊娠前后增补叶酸预防神经管畸形的成本效果分析

目的：对我国妇女妊娠前后服用叶酸预防神经管畸形干预进行成本效果评价。方法：从社会的角度，构建决策树进行成本效果分析，并进行敏感性分析。结果：全国普遍实施增补叶酸干预的方案（FA2）和北方普遍干预且南方农村干预的方案（FA4）效果较好，敏感性分析显示疾病发生率、干预成本等因素影响其成本效果。结论：该干预是一项具有成本效果的预防技术，其中以北方普遍干预而南方农村干预方案的效果和成本效果较佳。     

Effect of folic acid supplementation on aluminum accumulation in rats

OBJECTIVE: Exposure to many xenobiotics may cause depletion of folic acid (folate), which is an essential vitamin for humans. Replacement of folate can be effective in protection against some diseases and in partial or total prevention of adverse effects related to xenobiotics. Aluminum (Al) is the most widely distributed metal in the outer crust of the earth. Its toxicity in humans is well known. However, there is no evidence that folate can decrease accumulation of Al to which humans can be exposed in many ways. The aim of the present study was to quantify organ Al accumulation and to evaluate whether there is any protective (or reductive) effect of folic acid on Al accumulation. METHODS: Male Wistar rats were assigned oral Al chloride (200 mg x kg(-1) x d(-1), n = 10, group 1) alone or in combination with folic acid (20 mg x kg(-1) x d(-1), n = 10, group 2) for 8 wk. At the end of the period, bone, kidney, brain, and blood samples were collected, and Al concentrations were determined by electrothermal atomic absorption spectrophotometry. RESULTS: Mean values of Al in the tissue samples from group 1 were higher than those from group 2 (all P < 0.05). No difference was observed in serum Al levels between groups (P > 0.05). CONCLUSION: These results suggest that folate supplementation might be useful to decrease Al accumulation in its main target organs, i.e., bone, kidney, and brain.     

Effect of folic acid supplementation on plasma zinc concentrations of young women

OBJECTIVE: Women of reproductive age are advised to consume supplements or fortified foods containing at least 400 microg/d folic acid for the prevention of neural tubes defects. Concerns exist about the adverse effects of folic acid on zinc status. METHODS: Seventy-eight women (18 to 49 y) were assigned for 12-wk to receive either a placebo or a 400 microg/d folic acid supplement. RESULTS: At 12-wk mean (95% CI) red cell folate increased by 431 (350-511) nmol/L in the supplemented group relative to placebo (P < 0.001) but there was no change in plasma zinc in either group (P = 0.213). CONCLUSIONS: Folic acid supplementation does not reduce plasma zinc concentrations in women of childbearing age.     

Effect of maternal folic acid supplementation on hepatic proteome in newborn piglets

ObjectiveThe objective of this study was to investigate the changes in the hepatic proteome of newborn piglets after maternal folic acid supplementation (FS).MethodsPregnant dams were fed a control diet (folic acid 1.3 mg/kg) or an FS diet (folic acid 30 mg/kg) during gestation. The liver samples of newborn piglets from each group were collected at birth for the analysis of the proteome using two-dimensional difference gel electrophoresis.ResultsThe results indicated that the expression levels of 11 proteins were changed dramatically in the newborn piglets after maternal FS. FS during gestation increased the content of proteins that regulate the immune response (90-kDa heat shock protein), energy metabolism (aconitase and succinate dehydrogenase), and intermediary metabolism (formiminotransferase cyclodeaminase and abhydrolase). In addition, maternal FS downregulated the expression of proteins associated with cellular signal transduction (heterogeneous nuclear ribonucleoprotein and exportin), proteolysis (ubiquitin-conjugating enzyme and porcine ε-trypsin), and cell migration regulation (actin-related protein-3).ConclusionThese findings suggest that maternal FS alters the expression abundance of several hepatic proteins that are involved in metabolic regulation, oxidative responses, and cancer-related processes.     

Effect of folic acid fortification on the incidence of neural tube defects

Amarin ZO, Obeidat AZ. Effect of folic acid fortification on the incidence of neural tube defects. Paediatric and Perinatal Epidemiology 2010. In a few countries enriched cereal grains have been fortified with folic acid to reduce the incidence of neural tube defects. The objective of this study was to analyse the effect of folic acid fortified foods on the incidence of neural tube defects in live newborns at Princess Badea Teaching Hospital, in the north of Jordan, before and after the national food fortification with folic acid was implemented. For the 7‐year period from 1 January 2000 to 31 December 2006, we retrospectively extracted the total number of births at Princess Badea Hospital, as well as the number of pregnancies affected by spina bifida and anencephaly, per 1000 births during the periods before (2000–01), during (2002–04) and after (2005–06) folic acid fortification of grain products, was implemented. Neural tube defects were defined in accordance with the International Classification of Diseases, 10th revision (ICD‐10): anencephaly, encephalocele and spina bifida. A total of 78 subjects with neural tube defects were recorded among 61 447 births during the study period. The incidence of neural tube defects decreased from 1.85 per 1000 births before fortification [95% confidence interval (CI) 1.2, 2.4] to 1.07 per 1000 births during the fortification period [95% CI 0.7, 1.5], and 0.95 after full fortification [95% CI 0.5, 1.5], a 49% reduction. The difference between incidence of neural tube defects in the periods before and after food fortification with folic acid was statistically significant. We conclude that food fortification with folic acid was associated with a significant reduction in the rate of neural tube defects in north Jordan.     

围孕期增补叶酸对子代哮喘及过敏性疾病的影响

哮喘是一种复杂的、异质性的慢性炎症疾病,致病机制尚不清楚,关于儿童哮喘及过敏性疾病的危险因素一直是研究热点。叶酸作为人体的必需营养素之一,在围孕期适量增补叶酸能够显著降低胎儿神经管缺陷等先天性异常的发生风险,同时,一些研究也发现增补叶酸会影响子代哮喘及过敏性疾病发生的风险,但是尚未得出一致结论。目前的研究仍存在一些问题,同时,叶酸增补的远期健康效应也值得随访追踪。