Photodynamic sterilization of red cells and its effect on contaminating white cells: viability and mechanism of cell death

BACKGROUND: Phthalocyanines are useful sensitizers for photodynamic sterilization of red cell concentrates. Various lipid-enveloped viruses can be inactivated with only limited red cell damage. Because white cells are involved in the immunomodulatory effects of blood transfusions, the study of the effect of photodynamic treatment on these cells is imperative. STUDY DESIGN AND METHODS: White cell-enriched red cell suspensions were photodynamically treated with either the hydrophobic Pc4 (HOSiPcOSi-(CH3)2(CH2)3N(CH3)2) or water-soluble aluminum phthalocyanine tetrasulfonate (AIPCS4) under virucidal conditions. Viability of white cell subpopulations on Days 0, 1, and 4 after treatment was determined by fluorescence-activated cell sorting by flow cytometric analysis of propidium iodide uptake. Apoptosis induction was studied by DNA ladder formation and staining for an early marker of apoptosis (annexin V). RESULTS: Treatment with Pc4 causes a significant decrease in cell viability of all white cells, as shown by prodidium iodide uptake. Monocytes and granulocytes are the most sensitive, and lymphocytes are relatively more resistant. Some of the cells die by apoptosis, which is induced within 30 minutes after treatment. Treatment with AIPCS4 damages only monocytes; other cell populations are not affected. CONCLUSIONS: Physicochemical properties of the photosensitizers partly determine their effect on white cells. Differences in intracellular localization are likely to be responsible for the effects observed.     

Improved quantification of protein in vaccines containing aluminum hydroxide by simple modification of the Lowry method

Aluminum (Al) components in vaccines are known to act as adsorbents that interfere with accurate protein quantification by the Lowry method. Therefore, certain modifications based on the characteristics and compositions of the vaccine are required for determination of protein contents.We investigated the effects of an additional centrifugal separation and found that protein contents were overestimated by up to 238% without centrifugation through a collaborative study performed with hepatitis B vaccines containing Al. However, addition of a centrifugation step yielded protein concentrations that were similar to the actual values, with small coefficients of variation (CVs). Proficiency testing performed in 11 laboratories showed that four laboratories did not have satisfactory results for vaccines containing aluminum hydroxide, although all laboratories were proficient in protein analysis when samples did not contain aluminum hydroxide. Incomplete resuspension of aluminum hydroxide solution with alkaline copper solution was the major cause of insufficient proficiency in these laboratories.     

Developing Fused Deposition Modeling Additive Manufacturing Processing Strategies for Aluminum Alloy 7075: Sample Preparation and Metallographic Characterization

Currently, no commercial aluminum 7000 series filaments are available for making aluminum parts using fused deposition modeling (FDM)-based additive manufacturing (AM). The key technical challenge associated with the FDM of aluminum alloy parts is consolidating the loosely packed alloy powders in the brown-body, separated by thin layers of surface oxides and polymer binders, into a dense structure. Classical pressing and sintering-based powder metallurgy (P/M) technologies are employed in this study to assist the development of FDM processing strategies for making strong Al7075 AM parts. Relevant FDM processing strategies, including green-body/brown-body formation and the sintering processes, are examined. The microstructures of the P/M-prepared, FDM-like Al7075 specimens are analyzed and compared with commercially available FDM 17-4 steel specimens. We explored the polymer removal and sintering strategies to minimize the pores of FDM-Al7075-sintered parts. Furthermore, the mechanisms that govern the sintering process are discussed.     

2005年浙江省绍兴市食品中铅镉砷铝污染现状及分析

目的 了解浙江省绍兴市本地食品铅、镉、砷、铝污染状况.方法 参照建立全国食品污染物监测系统和全球食品污染物监测规划(GEMS/FOOD)中推荐监测项目,对绍兴本地食品原粮、果蔬、茶叶、畜禽产品、水产品、食用菌、酱腌制品7大类31种1523份食品等进行了铅、镉、砷的监测,对糕点、油条进行了铝的监测.结果 2005年绍兴市本地食品中铅、总砷、无机砷、镉、铝的检出率分别是65.69%、55.85%、16.04%、70.45%和100%.食品中铅的国际食品法典委员会(CAC)标准超标率为0.53%、CAC超标率(标化后)为0.16%,皮蛋铅超标较严重为10.00%;食品中镉的国标超标率(标化后)为1.08%、CAC超标率(标化后)为1.42%;食品中总砷的国标超标率(标化后)为7.37%,砷超标样品是猪肾和猪肝,超标率分别为34.00%和23.64%;食品中无机砷的国标超标率(标化后)为0.27%,CAC超标率(标化后)为0.56%;糕点、油条过量添加膨松剂问题较严重,糕点、油条铝的合格率仅为85.00%和10.00%.结论 要进一步加强食品安全监管力度,尤其是皮蛋生产企业、油条摊位点等的监督管理.     

肠外营养液中的铝污染

目的:介绍肠外营养液中的铝污染。方法:本文根据国内外文献,对肠外营养液中的铝污染进行了综述。结果:肠外营养液中的铝污染研究仍处于探索阶段,但已找到了两个主要来源,给予了一些解决措施。结论:重视肠外营养液中的铝污染,加强肠外营养液的安全使用。     

稳定剂对84消毒液有效氯含量的影响

目的观察稳定剂对临床使用中84消毒液有效氯的稳定效果,寻找有效的稳定剂。方法采用碘量法,对临床使用中84消毒液有效含氯量稳定性进行分析。结果碘酸钾对84消毒液的有效氯含量可起到稳定作用,在含有效氯1000 mg/L的84消毒液内加入碘酸钾15 mg/L,在室温下储存96 h仍可保持有效氯含量不下降。在含有效氯1000 mg/L的84消毒液内加入30 mg/L聚合氯化铝亦可以起到稳定作用,能保持在96 h有效氯不下降。在含有效氯1000 mg/L的84消毒液内加入聚乙烯基吡咯烷酮与碘酸钾复合物,对有效含氯量明显增强并且能保持稳定;将十六脂与聚乙烯基吡咯烷酮、碘酸钾经复配后加入到使用中84消毒液内,其稳定性明显增强。结论临床使用中的84消毒液可以通过加入合适的稳定剂,以增强有效氯的稳定性;碘酸钾、聚合氯化铝等可增强84消毒液稳定性。     

六味地黄方对慢性铝暴露痴呆大鼠记忆功能保护作用的研究

目的 研究六味地黄方对慢性铝暴露痴呆大鼠记忆功能的保护作用及其机制.方法 采用胃肠道慢性染铝的方法制备记忆功能障碍大鼠模型,用Morris水迷宫实验检测大鼠空间学习记忆能力,并通过对血浆中超氧化物歧化酶(SOD)、丙二醛(MDA)的测定,研究慢性铝暴露导致大鼠记忆功能损害及六味地黄方的干预机制.结果 与正常对照组相比,模型组大鼠学习记忆能力降低(P<0.01,P<0.05),血浆MDA水平增加而SOD活性减低(P<0.01,P<0.05).与慢性铝暴露模型组相比,六味地黄方能提高大鼠血浆中SOD活性,降低MDA含量,改善了慢性铝暴露大鼠学习记忆功能(P<0.01,P<0.05).结论 六味地黄方通过增加体内抗氧化酶的活性,降低慢性铝暴露导致的神经脂质过氧化反应,从而干预慢性铝暴露对大鼠记忆功能的损伤.     

Influence of the Type of Cement on the Action of the Admixture Containing Aluminum Powder

The study of the effect of cement type on the action of an admixture increasing the volume of concrete (containing aluminum powder), used in amounts of 0.5–1.5% of cement mass, was presented. The tests were carried out on cement mortars with Portland (CEM I) and ground granulated blast-furnace slag cement (CEM III). The following tests were carried out for the tested mortars: the air content in fresh mortars, compressive strength, flexural strength, increase in mortar volume, bulk density, pore structure evaluation (by the computer image analysis method) and changes in the concentration of OH⁻ ions during the hydration of used cements. Differences in the action of the tested admixture depending on the cement used were found. To induce the expansion of CEM III mortars, a smaller amount of admixture is required than in the case of CEM I cement. Using the admixture in amounts above 1% of the cement mass causes cracks of mortars with CEM III cement due to slow hydrogen evolution, which occurs after mortar plasticity is lost. The use of an aluminum-containing admixture reduces the strength properties of the cement mortars, the effect being stronger in the case of CEM III cement. The influence of the sample molding time on the admixture action was also found.