Mjerenje raspodjele m-ksilena u tkivima štakora plinskokromatografskom analizom para iznad uzorka (head space gas chromatography)

An automated head space-gas chromatography (HS-GC) method was developed and evaluated for reliability in measurement of m-xylene in rat tissues. For tissue samples spiked with m-xylene (n=2), the analytical precision was better than 12% relative standard deviation (RSD) over the concentration range of 0.1 to cca 100 µg/g for liver and kidney, 0.1 to 170 µg/g for brain, 1.2 to 250 µg/g for fat, and 0.006 to 50 µg/mL for blood. For rats sacrificed immediately after an acute exposure to 1100 ppm of m-xylene, the relative tissue m-xylene concentrations were in the ascending order as follows: brain ≤ blood ≤kidney ≤ liver « fat. A precision of < 13% RSD was generally obtained for duplicale tissue samples from exposed animals, with m-xylene concentrations of about 10 µg/g of tissue.Razvijena je automatizirana metoda plinska head space kromatografije (izvorno: KS-GC), pouzdanost koje je provjerena mjerenjem m-ksilena u tkivima štakora. Analitička preciznost za uzorke tkiva (n-2) kojima je dodan m-ksilensneii u raspunu koncentracija od 0,1 do gotovo 100 µg/g za jetru i bubreg, uu 0,1 do 170 µg/g za mozak, od 1,2 do 250 µg/g za masno tkivo te od 0,006 do 50 µg/g za krv, pokazala se boljom od 12-postotne relativne standardne devijacije (RS0). Relativne koncentracije m-ksilena u tkivu štakora žrtvovanih odmah nakon akutne izloženosti m-ksilenu od 1100 ppm kretale su se ovim uzlaznim slijedom: mozak ≤ krv ≤ bubrcg < jetra « masno tkivo. Sveukupna preciznost iznosila je < 13% USD u paralelnim uzorcima izloženih životinja kod koncentracije m-ksilena u tkivu od oko 10 µg/g

Contrasting biological potency of particulate matter collected at sites impacted by distinct industrial sources

Association of biological effects in A549 cells with metal content in size-fractionated particles. Cytotoxic potencies according to lactate dehydrogenase (LDH) release and resazurin reduction were regressed against total, water-soluble, and non-water-soluble metals. Pearson product–moment correlation coefficient r-values are presented. LDH release. A) Total metals. UFP, r = 0.77, p = 0.13; PM0.1–2.5, r = −0.55, p = 0.34; PM2.5–10, r = 0.32, p = 0.60; PM>10, r = −0.68, p = 0.21. B) Water-soluble metals. UFP, r = 0.51, p = 0.38; PM0.1–2.5, r = −0.64, p = 0.25; PM2.5–10, r = −0.35, p = 0.57; PM>10, r = −0.68, p = 0.20. C) Non-water-soluble metals. UFP, r = 0.75, p = 0.14; PM0.1–2.5, r = −0.46, p = 0.43; PM2.5–10, r = 0.36, p = 0.55; PM>10, r = −0.68, p = 0.21. Resazurin reduction. D) UFP, r = −0.19, p = 0.76; PM0.1–2.5, r = −0.63, p = 0.26; PM2.5–10, r = −0.60, p = 0.28; PM>10,r = 0.18, p = 0.78. Water-soluble metals. UFP, r = −0.20, p = 0.74; PM0.1–2.5, r = −0.41, p = 0.49; PM2.5–10, r = −0.09, p = 0.88; PM>10, r = 0.04, p = 0.95. Non-water-soluble metals. UFP, r = −0.12, p = 0.84; PM0.1–2.5, r = −0.65, p = 0.24; PM2.5–10, r = −0.62, p = 0.26; PM>10, r = 0.18, p = 0.77. (PDF 43 kb

Synthesis and Physicochemical Characterization of Mesoporous S

There exists a knowledge gap in understanding potential toxicity of mesoporous silica nanoparticles. A critical step in assessing toxicity of these particles is to have a wide size range with different chemistries and physicochemical properties. There are several challenges when synthesizing mesoporous silica nanoparticles over a wide range of sizes including (1) nonuniform synthesis protocols using the same starting materials, (2) the low material yield in a single batch synthesis (especially for particles below 60–70 nm), and (3) morphological instability during surfactant removal process and surface modifications. In this study, we synthesized a library of mesoporous silica nanoparticles with approximate particle sizes of 25, 70, 100, 170, and 600 nm. Surfaces of the silica nanoparticles were modified with hydrophilic-CH2–(CH2)2–COOH and relatively hydrophobic-CH2–(CH2)10–COOH functional groups. All silica nanoparticles were analysed for morphology, surface functionality, surface area/pore volume, surface organic content, and dispersion characteristics in liquid media. Our analysis revealed the synthesis of a spectrum of monodisperse bare and surface modified mesoporous silica nanoparticles with a narrow particle size distribution and devoid of cocontaminants critical for toxicity studies. Complete physicochemical characterization of these synthetic mesoporous silica nanoparticles will permit systematic toxicology studies for investigation of structure-activity relationships

Current Status and Future Perspectives of Mass Spectrometry Imaging

Mass spectrometry imaging is employed for mapping proteins, lipids and metabolites in biological tissues in a morphological context. Although initially developed as a tool for biomarker discovery by imaging the distribution of protein/peptide in tissue sections, the high sensitivity and molecular specificity of this technique have enabled its application to biomolecules, other than proteins, even in cells, latent finger prints and whole organisms. Relatively simple, with no requirement for labelling, homogenization, extraction or reconstitution, the technique has found a variety of applications in molecular biology, pathology, pharmacology and toxicology. By discriminating the spatial distribution of biomolecules in serial sections of tissues, biomarkers of lesions and the biological responses to stressors or diseases can be better understood in the context of structure and function. In this review, we have discussed the advances in the different aspects of mass spectrometry imaging processes, application towards different disciplines and relevance to the field of toxicology