Biodegradable Ultrasmall‐in‐Nano Gold Architectures: Mid‐Period In Vivo Distribution and Excretion Assessment

The persistence of metals in the body after the designed theranostic action has hampered the clinical translation of noble metal nanoparticles (NPs) to clinics. Therefore, the appealing behaviors of NPs for healthcare applications are still on the bench‐side. Here, quantitative evaluation in healthy murine models show that gold comprised in passion fruit‐like nanoarchitectures (NAs) are excreted daily over a 10 d period by both renal and biliary pathways after biodegradation to the building blocks. Furthermore, histological analyses confirm the absence of nephrotoxicity and the remarkable biocompatibility of NAs up to the higher tested amount of 150 mg kg^?1. These in vivo findings demonstrate that NAs are the first full‐inorganic disassembling nanoplatforms exhibiting a noticeable excretion rate from model organisms. Such results are a significant step in bringing noble metal nanotheranostics to the forefront of cancer treatments once again.     

Arsenic accumulation by arsenic-tolerant freshwater blue-green alga (Phormidium sp.)

Accumulation, biomethylation and excretion of arsenic by the arsenic-tolerant freshwater blue–green alga, Phormidium sp., which had been isolated from an arsenic-polluted environment, were investigated. The cellular growth curves were in fair agreement with a ‘logistic curve’ equation. The growth increased with an increase in the surrounding arsenic concentration up to 100 m?g g^?1. The cells survived even at 7000 m?g g^?1. The arsenic concentration of the cells increased with an increase of the surrounding arsenic concentration up to 7000 m?g g^?1. Phosphorus concentrations in the medium affected the growth and arsenic accumulation. No arsenic was accumulated by cells killed by ethanol. The arsenic was methylated to the extent of 3.2% of the total arsenic accumulated. When the cells were transferred into an arsenic-free medium, 85% of the arsenic accumulated was excreted; 58% of the excreted arsenic was in methylated form implying extensive methylation in the arsenic-free medium.     

Acute toxicity and rapid excretion in urine of tetramethylarsonium salts found in some marine animals

Acute toxicity in mice, and excretion in their urine, of tetramethylarsonium salts which are arsenic compounds found in some marine animals, were examined using synthetic tetramethylarsonium iodide. The oral, intraperitoneal and intravenous LD₅₀ values of tetramethylarsonium iodide [(CH₃)₄As⁺I^?] were determined to be 890, 175 and 82 mg kg^?1, respectively. When sublethal doses of tetramethylarsonium iodide were orally administered to mice, 53–58% of the arsenic administered was recovered in urine after 6 h and 65–81% after 72 h. High-performance liquid chromatography–inductively coupled plasma (HPLC–ICP) and fast atom bombardment mass spectrometric (FAB MS) analyses revealed that a tetramethylarsonium salt was the only arsenic compound excreted in urine. These results suggested that the major part of orally administered tetramethylarsonium iodide was absorbed from the gastrointestinal tract in mice and then rapidly excreted in urine without biotransformation.     

High resolution gas chromatography/mass spectrometric characterization of urinary metabolites of N,N-diethyl-m-toluamide (DEET) in man

Studies of the pharmacology and toxicology of the popular insect repellant, N,N-diethyl-m-toluamide (DEET), have largely been done in animal models using radioactive tracing without the structural elucidation of its metabolites. This paper describes a high resolution gas chromatography/mass spectrometry (GC/MS) technique and reports the results of the preliminary characterization of the metabolites of DEET in the urine of a 30-year-old man who had been exposed to DEET contained in a commercial product. The metabolites were extracted and separated with an OV-101 glass capillary column, 30 m × 0.3 mm, and mass spectrometric elucidations were carried out with both Electron Impact (EI) and Chemical Ionization-Methane (MCI) modes. Oxidation of the benzylic moiety and hydroxylation of the sidechain of DEET molecules appeared to be the predominate routes of metabolism in man. The artifacts were also proposed.     

Development of HPLC-MS/MS method for the simultaneous determination of metabolites of organophosphate pesticides,synthetic pyrethroids,herbicides and DEET in human urine

We developed an isotopic dilution high-performance liquid chromatography (HPLC)/tandem mass spectrometer (MS/MS) method to rapidly and accurately quantify nine metabolites of several classes of pesticide in 1 mL human urine specimens. The analytes covered in the method are two organophosphate (OP) pesticide metabolites: 3,5,6-trichloro-2-pyridinol (TCPy), 2-isopropyl-6-methyl-4-pyrimidinol (IMPY); three synthetic pyrethroid metabolites: 3-phenoxy benzoic acid (3-PBA), 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA) and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-1(1-cyclopropane) carboxylic acid (t-DCCA); three herbicide metabolites: 2,4-dichlorophenoxyacetic acid (DCPAA), 2,4,5-trichlorophenoxyacetic acid (TCPAA) and atrazine mercapturate; and one insect repellent: N,N-diethyl-meta-toluamide (DEET). The analytes are first deconjugated by incubating with acetate/β-glucuronidase buffer at 37°C for 17 h. The deconjugated analytes are extracted and concentrated from the urine matrix using solid-phase extraction cartridges, separated through C18 reversed phase HPLC, and analysed on MS/MS. The MS/MS was operated in positive and negative electrospray ionisation switch mode. Two ions from each analyte and one from each labelled internal standard are monitored for quantification and confirmation. The limit of detections (LODs) for all the analytes are in the low parts-per-trillion (0.05 ng/mL) except TCPy where it was 0.5 ng/mL) with a wide linear range (0.05 up to 40 ng/mL) and provides high accuracy (recoveries: 90–118%) and high precision (coefficient of variation <15%). The method accuracy was also verified by the analysis of proficiency testing urine samples. We analysed 101 urine samples for a recent California study cohort, and detection frequencies ranged from ~100% to 0%: 3-PBA (98%), IMPY (91%), TCPy, (89%), DCPAA (66%), 4-F-3-PBA (11%), TCPAA (0%).     

Electrodeless Piezoelectric Quartz Crystal Sensor for Determination of Total Urinary Reducing Sugar

A glucose-sensing system was developed in which an electrodeless piezoelectric quartz crystal was used to measure mass changes on the surface of a quartz plate during the reduction of Ag(NH₃)⁺₂ by glucose. A satisfactory correlation was obtained between the frequency shift and the glucose concentration in the range 1.0–25 mM, and the total reducing sugar in urine was determined. Treatment with 8 M nitric acid after each measurement was effective for cleaning the quartz surface, and the electrodeless piezoelectric quartz crystal sensor possessed excellent reproducibility and reusability during repeated use over 400 times. For the determination of total reducing sugar in urine (or blood), the present method can avoid the interferences occurring in a colorimetric method such as the color and turbidity of clinical specimens.     

Influence of Bacillus subtilis on the growth of calcium oxalate

The influence of the bacteria Bacillus subtilis (B. subtilis) on the nucleation, growth and aggregation of calcium oxalate (CaOx) crystals in aqueous solution has been studied. The crystals obtained were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X‐ray powder diffractometry. The results show that, in the presence of B. subtilis, quasi‐hexagonal calcium oxalate monohydrate (COM) crystals are obtained after 24 hours of reaction at a temperature of 30°C ± 1K. However, without the presence of the bacteria, irregular CaOx crystals were obtained which contain two crystal phases: COM and calcium oxalate dihydrate (COD). This suggests that B. subtilis may promote the crystallization of COM, the major component of urinary stone. The formation mechanism of CaOx crystals in the presence of B. subtilis is explored, indicating that the cell walls and extracellular proteins of the bacteria may act as templates to induce the nucleation, growth and aggregation of CaOx crystals. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

自身免疫性甲状腺疾病患者的尿碘与外周血sFas和sFasL的关系研究

为了解重庆地区自身免疫性甲状腺疾病（AITD）患者外周血sFas与sFasL的表达情况与尿碘的关系,探讨AITD发病的机制,采用病例对照研究,检测并分析各组人群外周血sFas和sFasL及尿碘的含量。结果表明,GD与HT组体内的碘营养状况高于对照组（P〈0．0001）,GD组的sFas含量高于对照组,GD和HT组的sFasL含量高于对照组,其差异具有统计学意义。外周血中sFas与sFasL之间存在负相关关系,随着尿碘含量的增高,sFas含量下降,sFasL含量升高。提示AITD患者体内存在高碘营养状况,高碘可能导致细胞的过度凋亡,从而诱发AITD。     

蛋白质-铬天青S体系的弹性光散射及其初步分析应用

在pH3.5左右的柠檬酸-NaOH介质中, 蛋白质与铬天青S可以通过以静电引力为主的分子间作用力结合生成大分子离子缔合物, 产生最大散射波长约为370nm的弹性光散射信号。基于这一现象可以测定低至0.02μg.mL^-^1的血清白蛋白, 工作曲线在0-1.0μg.mL^-^1范围内呈线性关系。这一新方法的灵敏度比Coomassie亮蓝法高50倍。用普通的荧光分光光度计测量了这一体系的散射光谱, 研究了pH, 离子强度和试剂浓度等实验条件对散射光强的影响, 考察了阳离子、阴离子和非离子表面活性剂以及氨基酸和常见金属离子对反应体系的作用。将这一方法用于测定尿中微量蛋白, 结果满意。     

用傅立叶红外光谱测定泌尿系结石中的草酸钙

对泌尿系结石的组成进行结构分析,为分析结石病的产生原因及预防复发提供参考,在临床诊断和治疗上具有重要意义.傅立叶红外光谱是研究泌尿系结石构造的一种较理想的分析手段.用红外光谱仪定量分析泌尿结石中草酸钙采用的内标法、吸光度比值法和一阶导数法进行了比较,建立的分析方法可以简便对草酸钙混合结石中一水草酸钙(COM)和二水草酸钙(COD)进行定量测定,分析结果可初步满足临床诊断的要求.