Geochemical fractionation and bioavailability of ²⁴¹Am, ⁶⁰Co and ¹³⁷Cs in Fluvisol soil after sharp temperature variation before the growing season

This paper deals with the influence of sharp temperature variations on the geochemical fractionation and bioavailability of 241Am, 60Co and 137Cs in Fluvisol soil. The study was performed using soil contaminated with aqueous solutions of 241Am, 60Co and 137Cs in the laboratory and stored for three years at temperatures within the range of 10–18 ºC and soil moisture from 20 to 30 wt %. Afterward the soil was divided into three equal parts and conditioned for one month at 10–18 ºC, −18 ºC and 40 ºC temperature regimes, respectively. The impact of the storage conditions on geochemical forms of the radionuclides was investigated using single extraction of exchangeable 137Cs with 1 M NH4NO3 and sequential extraction of 241Am and 60Co, and by gamma-spectrometric measurement. The influence of temperature rise up to 40 ºC over a period of one month on the transfer factors (TFs) of the radionuclides from the investigated soil to orchard grass (Dactylis glomerata L.) was evaluated. The results showed that deep freezing and a sharp temperature increase continuing for one month led to re-distribution of 241Amand 60Co between the soil phases and provoked an increase of the exchangeable 137Cs. Freezing led to a decrease of 241Am in the residual fraction and an increase of oxide-bound americium. The storage at frozen conditions led to decrease of oxide bounded 60Co and increased immobilization in the residual fraction. Conditioning at high temperature increased the migration ability of 241Amand 137Cs, while immobilization of 60Co was registered. Conditioning at a sharp temperature increase before the growing season led to higher values of the TFs of all the studied radionuclides. This effect was highest for 137Cs. The sharp temperature change of contaminated Fluvisol soil lasting one month was found to create a risk of increased migration and bioaccumulation of radionuclides

Examining The Effect Of The Online Radiological Consultation Platform StatDx

StatDx е онлайн платформа за бърза справка в полза на клиничните радиолози и образни диагностици. Състои се от редица свързани помежду си статии за диагнози и диференциални диагнози, позволяващи бързо и интуитивно търсене, сортиране и сравнение на нозологични единици и образни белези. Системата е снабдена с богат диапазон от изображения, включително схеми и образи от различните образни модалности, всички от които подробно анотирани. Тази система бе въведена за ползване в Клиниката по образна диагностика в УМБАЛ „Света Марина“ – Варна в началото на 2017 г. Над година след това бе проведено вътрешно анонимно проучване на индивидуалните мнения на ползващите я лекари – в това число 14 специалисти по образна диагностика и 8 специализанти. Добитите данни демонстрират преобладаващо позитивна оценка на платформата StatDx в клиниката.StatDx is an online consultation platform for clinical radiologists and diagnostic imaging specialists. It comprises a large database of interconnected articles on diagnoses and differential diagnoses, allowing for quick and intuitive searches, sorting, and comparison between varying disease entities and between their imaging characteristics. This system is richly illustrated with vast amounts of drawings, schematics and imaging studies, all of which comprehensively annotated. StatDx was introduced to the Department of Diagnostic Imaging at St. Marina University Hospital, Varna in early 2017. Over a year later an anonymous internal study was conducted among the physicians using this system – including 14 specialists in Radiology and 8 Radiology interns. The data acquired pointed at a predominantly positive assessment of StatDx at the Department

Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules

The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy.The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy

Silencing the majority of cerebellar granule cells uncovers their essential role in motor learning and consolidation.

Cerebellar granule cells (GCs) account for more than half of all neurons in the CNS of vertebrates. Theoretical work has suggested that the abundance of GCs is advantageous for sparse coding during memory formation. Here, we minimized the output of the majority of GCs by selectively eliminating their CaV2.1 (P/Q-type) Ca2+ channels, which mediate the bulk of their neurotransmitter release. This resulted in reduced GC output to Purkinje cells (PCs) and stellate cells (SCs) as well as in impaired long-term plasticity at GC-PC synapses. As a consequence modulation amplitude and regularity of simple spike (SS) output were affected. Surprisingly, the overall motor performance was intact, whereas demanding motor learning and memory consolidation tasks were compromised. Our findings indicate that a minority of functionally intact GCs is sufficient for the maintenance of basic motor performance, whereas acquisition and stabilization of sophisticated memories require higher numbers of normal GCs controlling PC firing

Purkinje cell-specific ablation of CaV2.1 Channels is sufficient to cause cerebellar ataxia in mice

The Cacna1a gene encodes the α1A subunit of voltage-gated CaV2.1 Ca2+ channels that are involved in neurotransmission at central synapses. CaV2.1-α1- knockout (α1KO) mice, which lack CaV2.1 channels in all neurons, have a very severe phenotype of cerebellar ataxia and dystonia, and usually die around postnatal day 20. This early lethality, combined with the wide expression of CaV2.1 channels throughout the cerebellar cortex and nuclei, prohibited determination of the contribution of particular cerebellar cell types to the development of the severe neurobiological phenotype in Cacna1a mutant mice. Here, we crossed conditional Cacna1a mice with transgenic mice expressing Cre recombinase, driven by the Purkinje cell-specific Pcp2 promoter, to specifically ablate the CaV2.1- α1A subunit and thereby CaV2.1 channels in Purkinje cells. Purkinje cell CaV2.1-α1A-knockout (PCα1KO) mice aged without difficulties, rescuing the lethal phenotype seen in α1KO mice. PCα1KO mice exhibited cerebellar ataxia starting around P12, much earlier than the first signs of progressive Purkinje cell loss, which appears in these mice between P30 and P45. Secondary cell loss was observed in the granular and molecular layers of the cerebellum and the volume of all individual cerebellar nuclei was reduced. In this mouse model with a cell type-specific ablation of CaV2.1 channels, we show that ablation of CaV2.1 channels restricted to Purkinje cells is sufficient to cause cerebellar ataxia. We demonstrate that spatial ablation of CaV2.1 channels may help in unraveling mechanisms of human disease

Neuromuscular synaptic transmission in aged ganglioside-deficient mice

Gangliosides are sialylated glycosphingolipids that are present in high density on neuronal membranes, especially at synapses, where they are assumed to play functional or modulating roles. Mice lacking GM2/GD2-synthase express only the simple gangliosides GD3 and GM3 and develop progressive motor behaviour deficits upon ageing, apparently due to failing complex ganglioside-dependent maintenance and/or repair processes or, alternatively, toxic GM3/GD3 accumulation. We investigated the function of neuromuscular junctions (NMJs) of aged (>9 month-old) GM2/GD2-synthase null-mutant mice, because synaptic dysfunction might develop with age and could potentially contribute to the late-onset motor phenotype. In addition, we studied NMJs of old mice lacking GD3-synthase (expressing only O- and a-series gangliosides), which do not show an overt neurological phenotype but may develop subclinical synaptic deficits. Detailed electrophysiological analyses showed subtle changes in presynaptic neurotransmitter release. Acetylcholine release at 40 Hz nerve stimulation at aged GM2/GD2-synthase null-mutant NMJs ran down slightly more pronounced than at wild-type NMJs, and spontaneous acetylcholine release rate at GD3-synthase null-mutant NMJs was somewhat higher than at wild-type, selectively at 25 degrees C bath temperature. Interestingly, we observed faster kinetics of postsynaptic electrophysiological responses at aged GD3-synthase null-mutant NMJs, not previously seen by us at NMJs of young GD3-synthase null-mutants or other types of (aged or young) ganglioside-deficient mice. These kinetic changes might reflect a change in postsynaptic acetylcholine receptor behaviour. Our data indicate that it is highly unlikely that transmission failure at NMJs contributes to the progressive motor defects of aged GM2/GD2-synthase null-mutants and that, despite some kinetic changes of synaptic signals, neuromuscular transmission remains successful in aged GD3-synthase null-mutant mice. Apparently, mutual redundancy of the different gangliosides in supporting presynaptic function, as observed previously by us in young mice, remains adequate upon ageing or, alternatively, gangliosides have only relatively little direct impact on neuromuscular synaptic function, even in aged mice. (C) 2009 Elsevier Inc. All rights reserve

A randomized, double-blind study of zinpentraxin alfa in patients with myelofibrosis who were previously treated with or ineligible for ruxolitinib:stage 2 of a phase II trial

Not available.</p

An approach to develop personalized radiopharmaceuticals by modifying 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG)

Background: A challenge for modern medicine is the development of clinical protocols for precise diagnosis and therapy. This study aimed to propose a simple method for modification of 2-[18F]FDG used routinely in hospitals in a way, appropriate for patients’ personalized radiopharmaceuticals approach. Material and methods: For the purposes of the presented study chemo selective method for indirect radiofluorination was applauded to custom synthesized aminooxy- and hydrazine-functionalized tetrazines for 18F-glycolation via oxime or hydrazone formation. 2-[18F]FDG produced with medical baby cyclotron in Nuclear Medicine Clinic at the University Hospital St. Marina-Varna, was used. Thin layer chromatography (TLC) and radio TLC were used to follow the progress of synthesis and to determine radio chemical yield (RCY). Results: The 2-[18F]FDG was modified with two bifunctional tetrazines aminooxy-acetic acid-6-(2-aminooxy-acetoxy)-[1,2,4,5] tetrazin-3-yl ester (Tz1) and {3-[4-(6-phenyl-[1,2,4,5]tetrazin-3-yl)-phenoxy]-propyl}-hydrazine (Tz2) via oxime and hydrazone formation. The radiolabeling was carried out as one-pot reaction with following parameters: temperature 70–75°C; catalyst p- diaminobenzene (Cat.); pH = 4.2; time 30 minutes; RCY = 70–99%. The radiolabeled tetrazines are appropriate for further bioorthogonal (pretargeting) strategy by click reactions with trans-cyclooctene conjugated bioactive molecules. The methodology is applicable to standard clinical conditions