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Abstract  

Concentrations of uranium in several brands of di-calcium phosphate commercialized in Brazil were measured by means of a recently developed electrofission/SSNTD technique. These results, plus the alimentary habits of brazilian consumers, allowed to estimate the radiation exposure. Calculations of internally localized doses (hot spots) were worked out and some aspects of radiobiological effects and risks were addressed.

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Abstract  

For the purpose of studying the secretion of exogenous toxic metals into hair, relation between their concentrations in hair and those in organs, and the metal shift, Hg or Mn was orally administered to guinea pigs for protracted periods, the distributions of metals in hair and organs were examined by means of neutron activation analysis. It was found that the administration of Hg at high dose resulted in abnormally high Hg levels in hair from the 2nd dosing week and in organs after 25 week dosing, and in a reduced motor activity after 25 week administration. There occurred metal shifts in hair as well. Administration of Mn at high doses, on the other hand, showed no such biological influences, although a dose-dependent increase of Mn in hair was detected with time.

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In 1930, Bortels showed that molybdenum is necessary for nitrogen fixation in Acetobacter, and in 1939 Arnon and Stout reported that molyb denum is essential for life in higher plants. Nitrogenase is the nitrogen-fixing enzyme complex, while nitrate reductase requires molybdenum for its activity. Molybdenum occurs in the earth crust with an abundance of 1.0–1.4 mg/kg. The molybdenum content of the vegetation is determined by the amount of this element in the soil and its pH-value. The weathering soils of granite, porphyry, gneiss and Rotliegendes produce a molyb denum-rich vegetation. Significantly poorer in Mo is the vegetation on loess, diluvial sands, alluvial riverside soils and especially on Keuper and Muschelkalk weathering soils, which produce legumes and, e.g. cauliflower with molybdenum deficiency symptoms. The molybdenum content of the flora decreases with increasing age. Legumes store the highest molybdenum levels in the bulbs of their roots; on average, they accumulate more molybdenum than herbs and grasses do. The danger of molybdenum toxicity in plants is small.

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Abstract  

One formulation of14C labeled and another of99mTc labeled 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) were administered i.v. to tumor (glioma) bearing rats. The radiopharmacokinetics of14C-CCNU were followed up to 24 hours post injection. On a per organ basis the blood, liver, small bowel, kidney cortex and muscle contained most of the activity. Optimum tumor to organ ratios occurred at 4–12 hours. The99mTc-CCNU biodistribution was determined at 4 hours and compared to99mTc-NaTcO4. Tumor capsule to brain (29.5) and to muscle (10.59) ratios suggest99mTc-CCNU to be a potential tumor seeking agent.

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Acta Chromatographica
Authors: Aida Begic, Ana Djuric, Borko Gobeljic, Ivana Stevanovic, Vera Lukic, Ivan Stanojevic, Milica Ninkovic, Luciano Saso, Danilo Vojvodic, and Mirjana Djukic

The aim of our work was to optimize and apply simple high-performance liquid chromatography method with ultraviolet detection (HPLC—UV) for simultaneous determination of reduced (GSH) and oxidized (GSSG) glutathione in biological matrix (specifically, the rat liver tissue was used herein), since the ratio between oxidized and reduced glutathione forms (GSSG—GSH) has been recognized as an important biological marker of oxidatively depleted GSH in oxidative stress (OS)-associated diseases and poisonings. An isocratic chromatographic separation of GSH and GSSG (2.8 min and 6.3 min, respectively) was performed with the mobile phase consisted of sodium perchlorate solution (pH adjusted to 2.8) at flow rate of 1 mL min−1, detection set at 215 nm, and column temperature of 40 °C. The method offers short run time, linearity in the range of 0.01—200 μM concentration for both compounds (R 2 = 1), low limits of detection and quantification (GSH: 0.18 μM and 0.56 μM, GSSG: 0.52 μM and 1.58 μM, respectively), precision, accuracy (bias < 2%), and high reproducibility.

Through suitable sample handling, an overestimation of GSSG was prevented. High recovery (>99%) was achieved. The method was successfully applied for the analysis of GSH and GSSG in liver homogenates of Wistar rats intraperitoneally exposed to cadmium (Cd) (1 mg kg−1 CdCl2/21 days). Regardless of other Cd-mediated hepatotoxicity mechanisms, herein, we have exclusively interpreted/emphasized oxidative GSH depletion.

The presented method is acceptable for a routine analysis of GSH and GSSG in biological matrix, while the calculated ratio GSSG—GSH is considered as a valuable OS marker.

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Abstract  

The femur samples obtained from the general populations were dissected into five different parts: the distal end (DE), distal shaft (DS), middle shaft (MS), proximal shaft (PS) and proximal end (PE). The dissections were performed in the same manner as for the persons exposed to plutonium occupationally. The concentrations of plutonium in these sections were determined by a radiochemical procedure utilizing solvent extraction and alpha-spectrometry. The preliminary results indicate that the distribution of plutonium in the femur was nonuniform and was highest in the proximal end followed by distal end.

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Reliable determination of microbial or transgenic Cry toxins is an essential issue in food and feed analyses, and enzyme-linked immunosorbent assays (ELISAs) are the method of choice for quantifying these toxins currently in food and environmental analysis. Internal Quality Control (IQC) is an indispensable method to assess accuracy, precision, and reproducibility of analytical measurements. To assess the utility of the ELISA method, IQC was performed on EnviroLogix Cry1Ab/Cry1Ac QualiPlate ELISA with manufacturer supplied analytical standards. Applicability of negative and positive controls (C− and C+) was examined by Shewhart Control Charts for bias and Control Chart of the Range of Duplicates for precision. Linear regression (up to 5 ng ml−1 Cry1Ab concentration) of the commercial ELISA kit was compared to sigmoid calibration (up to 60 ng ml−1 Cry1Ab concentration). For immunoassay optimization process, possible matrix effects in different liquid and solid vertebrate tissues were examined by determination of the limit of detection values in these matrices.

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In this study pesticides with different chemical structures (dichlofluanid, endosulfan, simazine, tolyfluanid and triallate) were examined for their potential cytotoxic effect on proliferative activity of cell cultures of mammalian origin. Cell lines Madin-Darby Bovine Kidney (MDBK), Rabbit Kidney (RK13), Porcine Kidney (PK15), and semicontinual line of Bovine Embryonic Pulmonary Cells (BEPC) were used in the study. From these cell cultures cell proliferative activity was suppressed most intensively in PK15 culture by endosulfan (10 −1 −10 −6 M). The least effect on cell proliferation in all cell cultures tested, with the exception PK 15 (10 −1 −10 −2 M), was recorded after simazine exposure. On the basis of IC 50 values the cytotoxic effect was: dichlofluanid (IC 50 = 10 −3.94 M) > tolylfluanid (IC 50 = 10 −3.69 M) > endosulfan (IC 50 = 10 −3.24 M) > triallate (IC 50 = 10 −3.12 M) > simazine (IC 50 = 10 −1.78 M). The comparison of average IC 50 values of cell cultures revealed that the most sensitive cell lines were PK15 (IC 50 = 10 −3.27 M) and RK13 (IC 50 = 10 −3.21 M), whereas MDBK (IC 50 = 10 −2.55 M) and BEPC (IC 50 = 10 −2.52 M) were less sensitive to pesticide exposure.

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