Analytical techniques for cyanide in blood and published blood cyanide concentrations from healthy subjects and fire victims

Hydrogen cyanide can be produced by the pyrolysis of man-made polymers. Cyanide has been measured in the blood of healthy adults as well as the blood of fire survivors and fatalities. In healthy subjects the blood cyanide concentration of smokers is higher than that of non-smokers. Fire survivors and fatalities have been found to have higher cyanide levels than of control groups and the levels from fire fatalities are often higher than survivors. Blood concentrations quoted as normal, toxic or fatal are highly variable in the literature. Many studies have been performed to measure the blood cyanide levels in control subjects as well as those who have been exposed to fire but the values found differ. The values for control subjects can vary from none detected to 19 μmol dm⁻³ while those for fire survivors range from not detected to 150 μmol dm⁻³ and fatalities range from not detected to 284 μmol dm⁻³. Analytical techniques and published data are critically reviewed.Many of the existing antidotes for cyanide poisoning are highly toxic themselves and should ideally be administered at doses proportional to the amount of cyanide a patient has received to avoid compounding damage done by cyanide intoxication. For this reason, a rapid, accurate bedside assay of blood cyanide concentration that differentiates between bound and free cyanide would represent a leap forward in the clinical management of cyanide poisoning.     

NO in Viral Infections: Role and Development of Antiviral Therapies

Nitric oxide is a ubiquitous signaling radical that influences critical body functions. Its importance in the cardiovascular system and the innate immune response to bacterial and viral infections has been extensively investigated. The overproduction of NO is an early component of viral infections, including those affecting the respiratory tract. The production of high levels of NO is due to the overexpression of NO biosynthesis by inducible NO synthase (iNOS), which is involved in viral clearance. The development of NO-based antiviral therapies, particularly gaseous NO inhalation and NO-donors, has proven to be an excellent antiviral therapeutic strategy. The aim of this review is to systematically examine the multiple research studies that have been carried out to elucidate the role of NO in viral infections and to comprehensively describe the NO-based antiviral strategies that have been developed thus far. Particular attention has been paid to the potential mechanisms of NO and its clinical use in the prevention and therapy of COVID-19.     

低浓度含铅细颗粒物暴露大鼠体内生物转运研究

食品接触性塑料制品、可再生资源、汽车尾气中含有低浓度铅.铅等重金属体内蓄积严重影响机体健康,但机体长期暴露于铅环境的代谢依然未知.以低剂量含铅细颗粒物暴露为场景,探讨其在大鼠体内的生物转运及体内分布.通过比较每日吸入染毒(7.05±0.83)μg/m3及经口染毒0.42μg/d,连续染毒28 d.结果显示含铅细颗粒物入...     

Simultaneous measurements of indoor radon and thoron and inhalation dose assessment in Douala City,Cameroon

ABSTRACT

Radon, thoron and associated progeny measurements have been carried out in 71 dwellings of Douala city, Cameroon. The radon–thoron discriminative detectors (RADUET) were used to estimate the radon and thoron concentration, while thoron progeny monitors measured equilibrium equivalent thoron concentration (EETC). Radon, thoron and thoron progeny concentrations vary from 31?±?1 to 436?±?12 Bq?m^–3, 4?±?7 to 246?±?5 Bq?m^–3, and 1.5?±?0.9 to 13.1?±?9.4 Bq?m^–3. The mean value of the equilibrium factor for thoron is estimated at 0.11?±?0.16. The annual effective dose due to exposure to indoor radon and progeny ranges from 0.6 to 9?mSv?a^–1 with an average value of 2.6?±?0.1?mSv?a^–1. The effective dose due to the exposure to thoron and progeny vary from 0.3 to 2.9?mSv?a^–1 with an average value of 1.0?±?0.4?mSv?a^–1. The contribution of thoron and its progeny to the total inhalation dose ranges from 7 to 60?% with an average value of 26?%; thus their contributions should not be neglected in the inhalation dose assessment.     

柠檬醛长时程嗅觉吸入的脑功能活动MEMRI研究

本文使用设计的嗅觉吸入装置使大鼠吸入挥发性柠檬醛或无气味空气，之后使用锰增强磁共振成像（MEMRI）的方法，观察长时程（24 h）吸入柠檬醛之后，大鼠脑功能活动变化情况．基于体素分析和感兴趣区（ROI）分析结果显示，与对照组相比，长时程吸入柠檬醛组大鼠伏隔核中心部（AcbC）、嗅小球层（GL）等脑区功能活动增强；而该组大鼠视皮层（VC）、听觉皮层（AC）、压后皮层（RSC）等脑区锰累积显著减少．且长时程吸入柠檬醛之后，大鼠脑区GL与关联的脑区功能相关性显著增强．从而表明MEMRI可用于长时程嗅觉吸入刺激的脑功能研究，并极具应用前景．     

Airborne Nanostructured Particles and Occupational Health

Nanotechnology is leading to the development in many field, of new materials and devices in many fields that demonstrate nanostructure-dependent properties. However, concern has been expressed that these same properties may present unique challenges to addressing potential health impact. Airborne particles associated with engineered nanomaterials are of particular concern, as they can readily enter the body through inhalation. Research into the potential occupational health risks associated with inhaling engineered nanostructured particles is just beginning. However, there is a large body of data on occupational and environmental aerosols, which is applicable to developing an initial assessment of potential risk and risk reduction strategies. Epidemiological and pathological studies of occupational and environmental exposures to airborne particles and fibers provide information on the aerosol-related lung diseases and conditions that have been observed in humans. Toxicological studies provide information on the specific disease mechanisms, dose–response relationships, and the particle characteristics that influence toxicity, including the size, surface area, chemistry or reactivity, solubility, and shape. Potential health risk will depend on the magnitude and nature of exposures to airborne nanostructured particles, and on the release, dispersion, transformation and control of materials in the workplace. Aerosol control methods have not been well-characterized for nanometer diameter particles, although theory and limited experimental data indicate that conventional ventilation, engineering control and filtration approaches should be applicable in many situations. Current information supports the development of preliminary guiding principles on working with engineered nanomaterials. However critical research questions remain to be answered before the potential health risk of airborne nanostructured particles in the workplace can be fully addressed. Disclaimer The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health     

Determination of diphenylamine in contaminated air of agricultural buildings using active sampling on solid sorbents

This paper reports the results of a study carried out with solid sorbents in order to establish the optimum procedure for sampling and determination of diphenylamine (DPA), the most widely used post-harvest chemical in apples, in the indoor air of apple storage buildings. Different sorbents (Amberlite XAD-2, Amberlite XAD-4, Supelpak 2, Florisil, and the octadecyl silica bonded sorbent, C-18) were evaluated for their capacity to efficiently retain DPA under different air sampling and storage conditions, whereas a desorption study of all sorbents tested was also performed to optimise a simple extraction procedure using low volumes of organic solvents. In general all sorbents produced acceptable results for DPA air sampling whereas DPA was recovered easily by the use of low volumes of both ethyl acetate and acetone from all sorbents studied thus making DPA a suitable analyte to be used in methods of indoor air analysis for multi-organic pollutants. However, the best results (analytical features, recovery results, and stability results during storage) were obtained by the use of Supelpak 2 as a sorbent for DPA active sampling. Limits of Quantification (LOQs) for the GC-NPD system ranged from 1.0 to 2.0?µg?m^?3 for 120 and 60?L air sampled, respectively. The developed air sampling procedure and analytical methodology was applied with success in the field to measure DPA residues in indoor air of two apple storage plants in Greece and results were further used to calculate the occupational inhalation exposure to DPA and consequently risk characterisation. Since DPA was detected in indoor air (at concentrations ranged from 1.6 to 580?µg?m^?3), there is no zero occupational risk for workers. However, the inhalation exposure of workers to DPA estimated in this study is far below the Acceptable Operator Exposure Level recently reviewed by the European Union and far below the critical exposure level for haematotoxicity systemic effect observed in carcinogenicity studies in rats for long-term inhalation exposure to DPA.     

A baseline inhalation toxicity model for narcosis in mammals

This paper presents the results of an analysis of the rodent inhalation literature and the development of a quantitative structure–activity relationships (QSAR) model for 4-hour LC50 as baseline toxicity to complement the baseline toxicity model for aquatic animals. We used the same literature review criteria developed for the ECOTOX database which selects only primary references with explicit experimental methods to form a high-quality database. Our literature review focused on the primary references reporting a 4-hour exposure for a single species of rodent in which the chemical had been clearly tested as a vapour and for which the exposure concentrations were not ambiguous. An expert system was used to remove reactive chemicals, receptor-mediated toxicants, and any test that produced symptoms inconsistent with non-polar narcosis. The QSAR model derived for narcosis in rodents was log LC50 = 0.69 × log VP + 1.54 which had an r ² of 0.91, which is significantly better than the baseline toxicity model for aquatic animals. This simple model suggests that there is no intrinsic barrier to estimating baseline toxicity for in vivo endpoints in mammalian or terrestrial toxicology.     

静脉滴注加雾化吸入沐舒坦治疗新生儿肺炎的效果观察

目的观察静脉滴注加雾化吸入沐舒坦治疗新生儿肺炎的临床应用效果。方法随机抽选于深圳市第二人民医院接受治疗的84例肺炎患儿,将其平均分成观察组与对照组(每组42例),分别给予两组患儿静脉滴注加雾化吸入沐舒坦与静脉滴注沐舒坦的方案进行治疗。结果观察组的血气指标改善程度大于对照组;观察组的各项临床症状消退时间与住院时间明显短于对照组的对应值;观察组的治疗总有效率为97.62%,明显高于对照组的85.71%,组间数据差异均具有统计学意义(P0.05)。结论给予新生儿肺炎幼儿实施静脉滴注加雾化吸入沐舒坦治疗方案,不仅能明显改善患儿的血气指标,缩短其症状消退时间与住院时间,也能显著提高患儿的治疗效果,降低不良反应的发生概率。