硼的理化特性及在动物生产中应用研究进展

硼是植物生长所必需的元素之一,目前,虽然尚未充分证实硼是动物必需的微量元素,但很多试验表明,硼对动物机体的物质代谢、生长发育、免疫功能等有着重大的影响。对硼的理化特性及其分布与含量、硼吸收与代谢、硼在动物体内的作用、硼与其他矿物元素的相互作用、高硼对动物的主要影响以及硼在动物生产应用中存在的问题和应用前景进行综述。     

45种食品中硼含量的测定及分析

目的测定常见食品中硼的含量,并分析食品中是否添加禁用防腐剂硼酸或硼砂。方法样品灰化后,用姜黄素分光光度法测定硼的含量。结果检测了3类45种样品中硼的含量,动物性食品硼含量范围0.26～0.75mg/kg;植物性食品硼含量范围较大0.31～21.83mg/kg;腌、炸类食品硼含量在0.61～5.29mg/kg之间。结论 45种食品均含有一定的硼,其中黄豆、葡萄干、绿豆等食品中硼含量较高,动物性食品硼含量较低。     

硼工业地区人群硼的日饮食摄入量

目的评价硼工业地区不同人群经饮食的硼摄入情况。方法于2003年7月—2004年9月以某硼矿开采和加工区域的硼作业工人(硼暴露组)、生活在硼工业区附近的非硼作业工人(社区对照组)和远离硼工业区的人群(背景对照组)作为研究对象,所有研究对象均为成年健康男性,用副盘法采集了24h的饮水和饭菜样品,分析了日饮食量,测定了饮食硼暴露量及摄入量。结果硼暴露组、社区对照组和背景对照组的日饮水量平均值分别为1575、1138和1232ml/d,日饭菜食用量(湿重)平均值分别为1867、2169和1664g/d,折合为干重分别为496、547和401g/d。饮水平均硼浓度分别为2.05、0.86和0.05mg/L;饭菜平均硼含量分别为9.46、6.19和3.29mg/kg(干基);饮食平均日硼摄入量分别为8.00、4.25和1.40mg/d。饮用严重受硼污染的职工食堂井水并在该食堂用餐的工人的日饮食硼暴露为95.5～469mg/d,平均为219.0mg/d。结论生活在硼矿区域的工人硼暴露的危险程度远高于其他人群,值得关注。     

环境中的硼及其生物作用

硼是一种天然存在的元素，以硼酸盐的形式存在于海洋、沉积岩、煤、页岩和一些土壤中。释入环境中的硼酸盐来源于海洋、地热蒸气、富含粘土的沉积岩自然风化。在较小程度上硼也可由人为来源释放。 硼是高等植物所必需的微量营养元素。最佳生长所需硼浓度存在种间差异。在世界上许多国家都曾观察到硼缺乏。在某些植物，硼缺乏与硼中毒之间范围狭小。 通过比较环境的无效应（ｎｏ－ｅｆｆｅｃｔ）硼浓度（ｌｍｇ／Ｌ）和一般环境中的硼浓度可知，硼对水生生态系统的不良影响危险性低。在少数富硼环境中，硼的天然浓度可较高。有理由认为，生活…     

食品中硼本底值调查研究进展

硼元素是广泛存在自然界的一种非金属元素。适量的硼对人体有益,然而过量则会危害人体健康。不良商贩为改善食品的口感将硼砂或硼酸加入食品中,目前的实验方法尚不能区分食品中的硼是天然存在还是人为加入的,因此要制定科学合理的硼限量标准,通过对硼本底值的测定排除天然硼的干扰。本文对目前各类食品中硼本底值研究进行综述,为制定硼限量标准提供参考。     

硼与骨关节病

硼在人和动物体内含量少，但与软骨代谢关系密切。缺硼被认为是骨质疏松的病因之一，饮食补硼可降低骨质疏松的发生，改善骨质疏松症患者的骨质和骨量。骨性关节炎与低硼有关，补硼能减少骨性关节炎的发病，减轻骨性关节炎的症状。硼和其他化合物被广泛用于防治氟骨症，且效果明显，但硼与大骨节病的关系尚处于初步探索阶段。     

硼烷化合物的急性毒理研究

硼烷化合物具有特殊的理化性质,主要用于火箭导弹、烈性炸药、高能燃料、中子计数器、脑瘤放射性治疗。硼硅橡胶熟化时,能溶于有机溶剂,加工成形方便;复盖金属陶瓷表面,光滑坚硬,不被腐蚀氧化,能耐高温1,000℃。硼烷化合物大部属于剧毒类。车间空气中的容许浓度,美国规定二硼烷0.1ppm,五硼烷0.01ppm,十硼烷0.05ppm;苏联规定五硼烷0.005ppm。为促进我国硼烷化合物生产的更大发展,初步进行了硼烷化合物的急性毒理实验,     

硼的环境水平

本文对环境中硼的水平进行了论述。主要论及空气地面水,地下水,雨水,污水及土壤中硼的分布情况和水平。岂时通过对不同国家,不同地区环境中硼的浓度的报道和比较,分析了造成周围环境中高硼污染的可能因素,并对水生生物和陆生生物体内硼的浓度变化和硼的可能来源进行了探讨,观察到了水生植物,陆生植物对硼都有生物积聚现象,但在水生食物链和动物中硼无生物扩增效应。     

2014—2018年安徽省部分豆类及豆制品中硼含量

目的调查安徽省部分豆类及豆制品中硼本底含量范围。方法选取2014-2018年安徽省具有代表性的豆类(黄豆、绿豆和红豆)及豆制品[腐竹、千张和其他(豆皮、粉皮等)]样品,按照《2014年国家食品安全风险监测工作手册(食品中硼的电感耦合等离子体质谱法标准操作程序)》和GB 5009.275-2016《食品中硼酸的测定》对所有样品中的硼和硼酸(硼砂)含量进行测定。结果豆类样品硼检出率为83.2%(159/191),硼含量的四分位数值(P25、P50、P75)和最大值分别为22.10、22.90、27.34和40.90 mg/kg;3种豆类中硼含量差异无统计学意义;豆类中硼含量的95%可信区间为5.52~34.24 mg/kg。豆制品硼检出率为84.5%(328/388),豆制品硼含量的四分位数值和最大值分别为5.99、20.07、38.25和51.47 mg/kg,3种豆制品中硼含量差异无统计学意义;豆制品中硼含量的95%可信区间为4.83~43.68 mg/kg;不同地区(皖南、皖北)豆类和豆制品中硼含量相比,差异均无统计学意义。结论安徽省豆类中硼含量为5.52~34.24 mg/kg,豆制品中硼含量为4.83~43.68 mg/kg。     

微量元素硼与人体健康

硼是植物的必需微量元素。近年来研究表明,硼也是人和动物需要的微量元素。概述了硼的生理功能及对人体健康的影响。     

Concentration of boron and other elements in human foods and personal-care products

The element boron is ubiquitous in the environment. Comparatively low concentrations of dietary boron affect several aspects of mineral metabolism in animals and human beings. Therefore, it is appropriate to determine precisely the concentration of boron in human foodstuffs and absorbed, inhaled, or ingested nonfood substances. In this article, we report the analyzed concentrations of boron and other elements in selected foods (animal products, water, condiments, confections, fruits, tuberized roots, vegetables, cereal grains, and spices) and personal-care products (analgesics, antibiotics, decongestants, antihistamines, dental hygiene products, gastric antacids, and laxatives). We conclude that daily intake of boron usually differs considerably between any two individuals for three main reasons. First, concentration of boron in water varies considerably according to geographic source. At some locations, boron in drinking water and water-based beverages may account for most of the total dietary boron intake. Second, individual food preference greatly influences daily intake of boron. Fruits, vegetables, tubers, and legumes have relatively much higher concentrations of boron than do cereal grains or animal tissues and fluids. Third, boron was determined to be a notable contaminant or major ingredient of many personal-care products.     

Biomarkers of environmental and workplace boron exposure

The purpose of this work was to identify an accurate, noninvasive biomarker of boron exposure that could be used in worker populations. Occupational exposure to boron is of concern due to high numbers of workers exposed, animal toxicity data suggesting reproductive effects, and lack of human studies. Total daily boron exposure was determined from duplicate samples of 24-hr food and fluid intake, plus workplace personal air monitoring in boron workers and comparison groups in northern China during 2003 and 2004. Boron was also measured in blood, semen, creatinine-corrected postshift urine, and 24-hr urine. Total daily boron exposure (mg/day) averaged 41.2 for men working in the boron industry and 2.3 for the comparison group. Boron concentration in postshift urine was correlated with 24-hr urine boron concentration (Pearson correlation coefficient = 0.85, p < 0.0001). Boron concentration in postshift urine was correlated with total daily boron exposure measured through food, fluid, and personal air monitoring (Pearson correlation coefficient = 0.83, p < 0.0001). Boron concentration in postshift urine was also correlated with internal dose measures of boron in blood and semen (Pearson correlation coefficient = 0.85, 0.80 respectively, p < 0.0001). This work suggests that creatinine-corrected, postshift urine boron concentration can be used as a biomarker of human boron exposure in worker populations.     

A novel method of boron delivery using sodium iodide symporter for boron neutron capture therapy

Boron Neutron Capture Therapy (BNCT) effectiveness depends on the preferential sequestration of boron in cancer cells relative to normal tissue cells. We present a novel strategy for sequestering boron using an adenovirus expressing the sodium iodide symporter (NIS). Human glioma grown subcutaneously in athymic mice and orthotopic rat brain tumors were transfected with NIS using a direct tumor injection of adenovirus. Boron bound as sodium tetrafluoroborate (NaBF(4)) was administered systemically several days after transfection. Tumors were excised hours later and assessed for boron concentration using inductively coupled plasma atomic emission spectroscopy. In the human glioma transfected with NIS, boron concentration was more than 10 fold higher with 100 mg/kg of NaBF(4), compared to tumor not transfected. In the orthotopic tumor model, the presence of NIS conferred almost 4 times the boron concentration in rat tumors transfected with human virus compared with contralateral normal brain not transfected. We conclude that adenovirus expressing NIS has the potential to be used as a novel boron delivery agent and should be explored for future clinical applications.     

硼暴露对男性精液质量影响

目的 研究硼暴露对男性精液质量的影响。方法 选择硼暴露组、社区对照组和背影对照组3组样本。进行精液分析。采用聚类分析法对精液的11个指标按性质相似程度分成若干类，用一组少量的指标代替原来的多个指标。新形成的指标既减少了变量个数，又综合反映了原多个指标变量中所包含的主要信息。通过研究硼暴露对新形成指标的影响可综合评价硼暴露对精液质量的影响。结果 变量聚类得到4个类成分指标，分别代表精子数量、精子活力、精子运动速度和精子直线运动能力；暴露组、社区对照组与背影对照组间的4个类成分指标差异无统计学意义。结论 硼暴露剂量13-430mg／d条件下，未发现硼暴露对精液质量造成负面影响。     

饮水硼暴露对固始鸡血细胞的影响

目的研究饮水添加不同水平硼对固始鸡血细胞的影响,为硼在人类和动物营养方面的正确使用提供科学依据。方法将1日龄240羽清洁级固始鸡随机分为对照组和硼100、200、400 mg/L染毒组,每组60羽。染毒组以饮水添加硼酸形式补硼,对照组饮用自来水,染毒6周。观察并记录染毒过程中鸡的采食、饮水、活动和临床症状,每周称重1次。每周末测定各组红、白细胞数及血红蛋白含量,白细胞分类计数,观察血细胞形态结构变化特点并显微摄影。结果与对照组比较,100mg/L染硼组固始鸡的临床症状和剖检无明显变化;第1～3周平均体重,第2周红细胞数,第4周红、白细胞数,第3、6周嗜碱性粒细胞比例,第1、4、6周淋巴细胞比例和第4周单核细胞比例均低于对照组,且差异有统计学意义(P<0.05或P<0.01);第1～3周各种血细胞形态结构受到轻微损伤。高剂量染硼组(硼添加量≥200mg/L),固始鸡的临床症状和剖检变化随硼添加剂量增大而趋于明显;各周体重,红、白细胞数和血红蛋白含量均降低,部分指标差异有统计学意义(P<0.05或P<0.01);各种白细胞比例变化较明显,其中淋巴细胞和嗜碱性粒细胞比例与对照组比较,部分指标有统计学意义(P<0.0...     

Daily boron intake from the American diet

Interest in boron as a naturally occurring trace element nutrient from the food supply is increasing. Mounting evidence suggests that boron is essential to human beings. This study explores the major food and beverage contributors of boron and estimates of daily boron intake from the American diet. Previous estimates in the literature of dietary boron consumption are based on limited foods and population segments. In this study we provide a more comprehensive assessment of boron consumption by the US population. A boron nutrient database of 1,944 individual foods was developed. These foods represent 95.3% by weight of all foods consumed in the US Department of Agriculture 1989-1991 Continuing Survey of Food Intakes by Individuals (1989-1991 CSFII). The Boron Nutrient Database (version 1.0) was then linked to the 3-day food records of 11,009 respondents to the 1989-1991 CSFII to generate the average daily boron intake for each person. The weighted 5th percentile, median, mean, and 95th percentile boron intakes, respectively, are 0.43, 1.02, 1.17 and 2.42 mg/day for men; 0.33, 0.83, 0.96 and 1.94 mg/day for women; and 0.40, 0.86, 1.01 and 2.18 mg/day for pregnant women. For vegetarian adults, these intakes are 0.46, 1.30, 1.47 and 2.74 mg/day for men and 0.33, 1.00, 1.29 and 4.18 mg/day for women. The top 2 boron contributors, coffee and milk, are low in boron, yet they make up 12% of the total boron intake by virtue of the volume consumed. Among the top 50 boron contributors, peanut butter, wine, raisins, peanuts, and other nuts are high in boron. As more data become available on daily boron requirements, the results of this study may be used to assess whether Americans' daily intake of boron is adequate.     

Effect of bevacizumab treatment on p-boronophenylalanine distribution in murine tumor

Previous studies have demonstrated that angiogenesis inhibitors can enhance tumor inhibitory effects of chemo- and radiotherapy via their action on tumor vessels. Here, we studied the effect of the angiogenesis inhibitor, bevacizumab (Avastin), on boron distribution in a murine tumor model. The human head and neck squamous cell carcinoma cell line was used for inoculation into mice. Boron-10 concentrations in tissues were measured by prompt γ-ray spectrometry (PGA). Hoechst 33342 perfusion and p-boronophenylalanine (BPA) distribution were determined by immunofluorescence staining. Our results revealed enhanced tumor blood perfusion and BPA accumulation in tumors after Avastin treatment, suggesting that combination of angiogenesis inhibition with treatment with boron compound administration may improve the efficacy of boron neutron capture therapy (BNCT) by modifying tumor vessels. In addition, our results also demonstrated the usefulness of immunofluorescence staining for investigating boron compound distribution at the cellular level.     

Cell-shaped silicon-on-insulator microdosimeters: characterization and response to <Superscript>239</Superscript>PuBe irradiations

This work tested the feasibility of a silicon-on-insulator microdosimeter, which mimics the size and shape of specific cells within the human body, to determine dose equivalent from neutron irradiation. The microdosimeters were analyzed in terms of their basic diode characteristics, i.e., leakage current as a function of bias voltage. Lineal energy spectra were acquired using two different converter layers placed atop the microdosimeter: a tissue-substitute converter made from high-density polyethylene, and a boron converter consisting of epoxy coated with boron powder. The spectra were then converted into absorbed dose and dose equivalent. Experimental results were compared to Monte Carlo simulations of the neutron irradiations, revealing good agreement. Uncertainty in the dose equivalent determinations was 7.5% when using the cell-shaped microdosimeter with the tissue-substitute converter and 13.1% when using the boron converter. This work confirmed that the SOI approach to cell-mimicking microdosimetry is feasible.     

Boron concentrations in milk from mothers of exclusively breast-fed healthy full-term infants are stable during the first four months of lactation

Because boron is a bioactive element that satisfies several of the criteria for essentiality in humans, the aim of the present work was to determine the profile of boron metabolism in human milk during the first 4 mo of lactation. The concentration of boron and other minerals was determined in archived milk collected (1980-84) 1 time/mo for 4 mo from lactating mothers of full-term, exclusively breast-fed infants living in Houston, TX. A linear model (treating month as a continuous variable) indicated that B concentrations were stable (P = 0.14) between mo 1 [3.88 +/- 0.6 mumol (42 +/- 6.5 microg)/L milk] and 4 [3.24 +/- 0.6 micromol (35 +/- 6.5 microg)/L milk, mean +/- SEM]. Mg concentrations increased slightly over time (1.18 +/- 0.09 to 1.36 +/- 0.09 mmol/L, P < 0.0001), whereas Ca concentrations decreased slightly (7.01 +/- 0.29 to 6.68 +/- 0.29 mmol/L milk, P < 0.02) and Zn decreased substantially (0.04 +/- 0.004 to 0.02 +/- 0.004 mmol/L milk, P < 0.0001). Similarities in findings reported here and earlier (from samples collected in St. John's, Newfoundland) provide further evidence that boron may be metabolically regulated. Future investigations of boron regulatory mechanisms should focus on metabolism of bone as the major storage site of B and kidney excretion, the major excretory route for B.     

Boron concentrations in milk from mothers of full-term and premature infants

BACKGROUND: Boron is a bioactive element that satisfies several of the criteria for essentiality in humans. OBJECTIVE: The objective was to establish the profile of boron metabolism in human milk. DESIGN: Lactating mothers of premature (PRT; n = 10, <2000 g birth weight, <37 wk gestation) and full-term (FT; n = 10, >2500 g, 39-41 wk gestation) infants living in St John's, Canada, collected milk samples once a week for 12 wk. Samples were analyzed for boron, copper, iron, selenium, and zinc by atomic emission or absorption spectrometry after wet-ash digestion with nitric acid and hydrogen peroxide in polytetrafluoroethylene tubes. RESULTS: A mixed-model analysis of variance indicated that boron concentrations were stable in full-term (30 and 28 mug/L milk; P = 0.5) but not in preterm (37 and 27 mug/L; P = 0.01) milk between weeks 1 and 12, respectively. As expected, there were reductions in the concentrations of copper (FT: 651 to 360 mug/L, P < 0.0001; PRT: 542 to 425, P = 0.05), iron (FT: 355 to 225 mug/L, P = 0.0003; PRT: 406 to 287, P = 0.002), selenium (FT: 26.9 to 18.6 mug/L, P < 0.0001; PRT: 28.7 to 20.4, P < 0.0001), and zinc (FT: 4060 to 1190 mug/L, P < 0.0001; PRT: 5970 to 1270, P < 0.0001) over time. CONCLUSIONS: The stable milk boron concentrations over time suggest that boron may be under homeostatic control. The patterns of change in copper, iron, selenium, and zinc concentrations in milk differ from those of boron. Further research is needed to elucidate the mechanism of milk boron secretion.