Maximum Label Research Articles

The Optimization Method for Synthesis of 99mTc-Rutin as Potential Radiotracer in The Development of Cancer Drugs From Flavonoid

Based on the Basic Health Research Data of Ministry of Health's of Indonesia in 2013, mortality rates from malignant and tumor malignancies in Indonesia are still high with prevalence of cancer is about 1.4%. Chemotherapy is still the primary choice in cancer modality that uses chemotherapeutic drugs to eradicate and inhibit the growth of cancer cells; however the cost this treatment is extremely high. Therefore, patient tends to seek alternative treatment such as consuming traditional herbal medicine for cancer treatment. Rutin is one of the attractive phytochemicals flavonoids because of its antioxidant activities. However, as traditional herbal medicine, its effectiveness is not yet been fully established due to the lack of scientific information. A radiotracer can be defined as a specific radiolabeled molecule that monitors the in vivo behaviour of a functional molecule, and can be used to provide biological information in a living system. Hence, to provide pharmacological information of rutin for cancer treatment, we synthesized radiolabeled flavonoid 99mTc-rutin as radiotracer. The aim of the present study is to develop 99mTc-rutin under varying conditions of rutin quantity, reducing agent concentration and incubation time. Labeling studies were performed by changing the selected parameters one by one and optimum labeling conditions were determined. After observing the conditions for maximum labeling efficiency, 99mTc-rutin was obtained with preparation of 700 μg of rutin with addition of 20 μg of SnCl2.2H2O as reductor and 1-3 mCi 99mTcO4- without any incubation. Radiochemical yield of 99mTc-rutin was determined with radio thin layer chromatography which was found 99.28 ± 0.14% and stable up to 4 hour. From the result of this study, the successfully labeled 99mTc-rutin can be used as a reference for following preclinical study. Furthermore radiolabeled 99mTc-rutin is expected as tools in research and development of rutin as cancer drugs from natural product to obtain detailed information its efficacy.Keywords: radiotracer, 99mTc-rutin, cancer, labeled compounds

On the strength of some trees

Let G be a graph of order p. A numbering f of G is a labeling that assigns distinct elements of the set 1,2,…,p to the vertices of G, where each edge uv of G is labeled fu+fv. The strength strfG of a numbering f:VG→1,2,…,p of G is defined by strfG=maxfu+fvuv∈EG,that is, strfG is the maximum edge label of G, and the strength strG of a graph G itself is strG=minstrfGf is a numbering of G.The strengths strT and strTn,k are determined for caterpillars T and k-level complete n-ary trees Tn,k. The strength strG is also given for graphs G obtained by taking the corona of certain graphs and an arbitrary number of isolated vertices. The work of this paper suggests an open problem on the strength of trees.

C-Fos mapping and EEG characteristics of multiple mice brain regions in pentylenetetrazol-induced seizure mice model

ABSTRACTPurpose: To confirm different local brain activities characterized in pentylenetetrazol (PTZ)-induced seizure model.Methods: we induced seizure response by a single dose of PTZ injection (45 mg/kg, i.p.). Local activity was recorded in different brain regions by EEG in time and c-Fos staining at different time points (0.5 h, 1 h, 2 h, 4 h) after PTZ treatment.Results: EEG recordings showed distinctive features of activation in different brain areas. With the aggravation of behavioral manifestations of seizures, the frequency and amplitude of the discharges on EEG were increasing gradually. The epileptic response on EEG immediately ended after reaching the maximum stage of seizures, followed by a short period of suppression. The labeling of c-Fos was enhanced in the medial prefrontal cortex, the piriform cortex, the amygdala, hippocampal CA1, CA3 and dentate gyrus, but inapparent in the striatum. The most potent changes in c-Fos were observed in cortex, amygdala nuclei, and dentate gyrus. EEG and c-Fos immunolabeling in neuronal activation showed discrepancies in the striatum. For each brain region, the maximum c-Fos labeling was observed at 2 h after injection and diminished at 4 h. The level of c-Fos immunoreactivity was even lower than the control group, which was accompanied by increased labeling of parvalbumin neurons (PVNs).Conclusions: These findings validated PTZ-induced seizure as a seizure model with a specific spatial-temporal profile. Neuronal activity was enhanced and then subsequently inhibited during seizure evolution.Abbreviations: AEDs: anti-epileptic drugs; AF: Alexa Fluor; CA1: Cornu Ammonis area 1; CA3: Cornu Ammonis area 3; DAB, 3: 3P-diaminobenzidine; DAPI: 4‘,6-diamidino-2-phenylindole; DG: dentate gyrus; EEG: electroencephalogram; GABA: gamma-aminobutyric acid; IEG: immediate early gene; mPFC: medial prefrontal cortex; NAc: nucleus accumbens; PB: phosphate buffer; PBS: phosphate buffered saline; PBST: phosphate buffered saline with Tween; PFA, paraformaldehyde; PTZ: pentylenetetrazol; PVN: parvalbumin neuron; ROI: regions of interest; SE: status epilepticus.

Reading the labels: mineral doses in food supplements

Introduction: Food Supplements (FS), used regularly by many adults, can add significant amounts of nutrients and other ingredients, such as minerals, to the diet. Although the Recommended Daily Allowance (RDA) for most nutrients is mainly provided by diet, mineral supplements (MS) are one of the largest growing category of FS used. Given the high prevalence of MS use among consumers and their potential for drug interactions [1], as well as adverse effects of excess consumption, special attention should be given to the Label Recommended Daily Dose (LRDD). As intake increases above the Tolerable Upper Intake Level (UL), the potential risk of experiencing adverse effects may rise [2].The aim of this study was to evaluate if LRDD of MS are in conformity with the RDA defined by European Union Directive [3]. Materials and methods: A total of 210 FS sold in Portuguese pharmacies, supermarkets, health shops and on internet were examined for LRDD of 14 minerals (Ca, Cl, Cr, Cu, Fe, F, I, K, Mg, Mn, Mo, P, Se and Zn). Selection criteria: oral solid pharmaceutical forms for adults, containing any of the 14 minerals, as stated in the label, regardless of the purpose of its use. Results: 56% of FS labels presented LRDD of at least one mineral > RDA and 6% of FS indicated LRDD > RDA, for 7 or more minerals. For most minerals (excluding Cl, F and K), Maximum Label Recommended Daily Dose (MLRDD) is much higher than RDA, with some FS mentioning doses of Se and Zn above UL defined by EFSA [2] (Table 1). Discussion and conclusions: It is noteworthy that some minerals can be harmful in large doses with risk of oral and systemic manifestations: e.g. excess of Zn may promote hypocupremia, anemia, gait and balance disorders and paresthesias; excess of Se can cause alopecia, hair and nail brittleness and garlic odor to breath. This study revealed that, for most minerals, the majority of FS labels recommended daily doses above RDA and some even above UL. Therefore, it is crucial to review doses of minerals present in FS ensuring the safety of these products.

Combined Toxicity of Insecticides and Fungicides Applied to California Almond Orchards to Honey Bee Larvae and Adults.

Beekeepers providing pollination services for California almond orchards have reported observing dead or malformed brood during and immediately after almond bloom—effects that they attribute to pesticide exposure. The objective of this study was to test commonly used insecticides and fungicides during almond bloom on honey bee larval development in a laboratory bioassay. In vitro rearing of worker honey bee larvae was performed to test the effect of three insecticides (chlorantraniliprole, diflubenzuron, and methoxyfenozide) and three fungicides (propiconazole, iprodione, and a mixture of boscalid-pyraclostrobin), applied alone or in insecticide-fungicide combinations, on larval development. Young worker larvae were fed diets contaminated with active ingredients at concentration ratios simulating a tank-mix at the maximum label rate. Overall, larvae receiving insecticide and insecticide-fungicide combinations were less likely to survive to adulthood when compared to the control or fungicide-only treatments. The insecticide chlorantraniliprole increased larval mortality when combined with the fungicides propiconazole or iprodione, but not alone; the chlorantraniliprole-propiconazole combination was also found to be highly toxic to adult workers treated topically. Diflubenzuron generally increased larval mortality, but no synergistic effect was observed when combined with fungicides. Neither methoxyfenozide nor any methoxyfenozide-fungicide combination increased mortality. Exposure to insecticides applied during almond bloom has the potential to harm honey bees and this effect may, in certain instances, be more damaging when insecticides are applied in combination with fungicides.

Residual toxicity of insecticides used against the Asian citrus psyllid and resistance management strategies with thiamethoxam and abamectin

The Asian citrus psyllid (ACP) is the key pest of citrus due to its role as vector of huanglongbing. ACP control mostly relies on frequent insecticide applications therefore increasing selection for insecticide resistance. Optimization of field application rates and rotation of insecticide modes of action (MoA) would minimize this risk. Baseline toxicity responses of ACP to commonly used insecticides provide a basis for defining application field rates and are thus needed to track potential development of resistance. Residual toxicities of 12 insecticides were evaluated through quantal response bioassays. The development of ACP resistance in response to monthly applications of two insecticides with different MoAs, abamectin and thiamethoxam, applied separately, in rotation or as mixtures was also tested. Highest residual toxicities were found for the abamectin + thiamethoxam mixture. In general, nymphs were more sensitive than adults to residues. Nymphs were 10 and 28 times more sensitive than adults to residues of thiamethoxam and imidacloprid, respectively. We found a wide range among ratios of maximum label field concentrations and estimated LC90s. Highest label rates for malathion and dimethoate were more than 30 times greater than LC90s, in contrast to abamectin, zeta-cypermethrin and fenpyroximate which were 4–7 times lower. Abamectin appeared to synergize the mixture of it with thiamethoxam. We observed resistance to both active ingredients, especially abamectin, after 8 months of sequential applications of both insecticides individually or in mixture. Rapid resistance development of the mixture relative to rotation was attributed to loss of the synergetic effect of abamectin on thiamethoxam.

Optimization of the spatial modulation function of vessel‐encoded pseudo‐continuous arterial spin labeling and its application to dynamic angiography

In vessel-encoded pseudo-continuous arterial spin labeling (ve-pCASL), vessel-selective labeling is achieved by modulation of the inversion efficiency across space. However, the spatial transition between the labeling and control conditions is rather gradual, which can cause partial labeling of vessels, reducing SNR-efficiency and necessitating complex postprocessing to decode the vessel-selective signals. The purpose of this study is to optimize the pCASL labeling parameters to obtain a sharper spatial inversion profile of the labeling and thereby minimizing the risk of partial labeling of untargeted arteries. Bloch simulations were performed to investigate how the inversion profile was influenced by the pCASL labeling parameters: the maximum (Gmax ) and mean (Gmean ) labeling gradient were varied for ve-pCASL with unipolar and bipolar gradients. The findings in the simulation study were subsequently confirmed in an in vivo volunteer study. Moreover, conventional and optimized settings were compared for 4D-MRA using four-cycle Hadamard ve-pCASL; the visualization of arteries and the presence of the partial labeling were assessed by an expert observer. When using unipolar gradient, lower Gmean resulted in a steeper spatial transition, whereas the width of the control region was broader for higher Gmax . The in vivo study confirmed these findings. When using bipolar gradients, the control region was always very narrow. Qualitative comparison of the 4D-MRA demonstrated lower occurrence of partial labeling when using the optimized gradient parameters. The shape of the ve-pCASL inversion profile can be optimized by changing Gmean and Gmax to reduce partial labeling of untargeted arteries.

Standardized Operational Evaluations of Catch Basin Larvicides from Seven Mosquito Control Programs in the Midwestern United States During 2017.

During June to September 2017, 7 mosquito control programs in the midwestern United States evaluated a total of 9 catch basin larvicide formulations using similar protocols. Treated basins were monitored among study sites to observe when larvicides failed to control mosquitoes in 25% or more basins within a site. Overall, when monitoring occurred within the maximum label duration of the larvicides, sites treated with a single larvicide tablet or briquet surpassed the 25% fail threshold more often than pellet and granular larvicide formulations. In 438 of the study basins, the depth from sump bottom to catch basin lid was measured. In basins that were deeper than 5 ft (1.5 m), larvicides failed to control mosquitoes significantly more often than those 5 ft or shallower.

Radiolabeling and Bio-distribution study of ICD-85 with Technetium-99m as a cancer treatment agent in mice

ICD-85 is a combination of three poly-peptides, ranging from 10,000 to 30,000 Dalton, derived from the venoms of an Iranian brown snake (Agkistrodon halys) and a yellow scorpion (Hemiscorpius lepturus) . Labeling of this ICD-85 was successfully achieved with 99m Tc, through direct method using SnF 2 as reducing agent. Labeled ICD-85 was injected into mice to determine the excretion pathway. The results show that the maximum labeling yield (>75%) was obtained by using 30 μg of ICD-85 in phosphate buffer (60 μl, pH 7.1) at room temperature. Bio-distribution studies with radiolabeled ICD-85 shows moderate clearance of the complex from blood. The improvement of the immunotherapeutic treatment of cancer requires a better knowledge of the biological actions of the ICD-85 since tissue distribution studies are very important for clinical purpose.

Effect of Travel Speed on Dispersion of Aqualuer 20-20 Sprayed by a Truck-Mounted Ultra-Low-Volume Sprayer Against Caged Aedes aegypti1.

The effect of travel speed of a truck-mounted ultra-low-volume (ULV) sprayer on its application efficacy was studied at St. Johns County Fairground, Elkton, FL, during summer 2015. The efficacy was assessed by spray deposition, droplet size spectrum, and 24-h mortality of caged adult Aedes aegypti, using 2 rows of sampling locations, 15 m apart and spread up to 122 m from the spray. Each location had a bioassay cage and an impinger droplet sampler, 1 m apart from each other, at 1.5 m off the ground. Aqualuer® 20-20 (20.6% permethrin AI and 20% piperonyl butoxide) was applied at the maximum label rate, travelling at 8, 16, and 32 km/h. Three replications were completed on 3 days at least a week apart, with 1 replication of each travel speed per day. On each application day the travel speeds were rotated. Overall, a travel speed of 32 km/h achieved the highest efficacy of Aqualuer® 20-20, followed by 16 km/h, and then 8 km/h, in an open field. In general, droplet size, deposition, and mosquito mortality increased with increasing travel speed. The increased travel speed will also enhance the work rate of a sprayer and operator, thus reducing the cost of ULV applications.

Application Efficacy of Vectobac WDG Against Larval Aedes aegypti Using Thermal Fog Technology.

The effectiveness of thermal fog application of Bacillus thuringiensis israelensis (Vectobac® WDG) against larval Aedes aegypti was evaluated in open and forest canopied environments in northeastern Florida, using a handheld IGEBA® TF34 thermal fogger (with water conversion kit). The product was applied at the maximum label rate of 1 kg/ha to linear transects, in each environment, containing empty 0.5-liter cups. After application, late-2nd to early-3rd instars of Ae. aegypti were added to each cup. Complete larval mortality occurred 48 h after treatment, 8 m away from the spray line in the open field while 63.4% larval mortality was achieved at this same distance in the forest canopy at 72 h posttreatment. Operational efficacy was then evaluated in an urban tropical environment in Key West, FL. In this study, empty plastic cups were placed in cryptic areas of a commercial lobster and crab trap yard. The 0.1-ha area was treated with Vectobac WDG at the maximum label rate using the same equipment. Aedes aegypti larval mortality from treated cups was >99% at 24 h posttreatment, whereas complete mortality was achieved at 48 h after application.

Sensitivity and Likelihood of Residual Herbicide Carryover to Cover Crops

AbstractResearch was conducted to evaluate the sensitivity of cover crops to a low rate of soil-applied herbicides and investigate the likelihood of herbicide carryover to fall-seeded cover crops following an irrigated corn crop. In the sensitivity study, herbicides were applied at a 1/16×rate (to simulate four half-lives) 1 d after cover crop planting, whereas for the carryover study residual herbicides were applied at a 2×rate at the maximum label corn height or growth stage and cover crops sown immediately after corn harvest. In the sensitivity experiment, atrazine, diuron, fluridone, fomesafen, metribuzin, pyrithiobac, and sulfentrazone reduced emergence of the leguminous cover crops Austrian winterpea, crimson clover, and hairy vetch. However, reduced biomass production of leguminous cover crops in the spring was only observed for atrazine, fluridone, and pyrithiobac. For rapeseed, atrazine, flumioxazin, fluridone, pyrithiobac, pyroxasulfone, sulfentrazone, and tembotrione reduced emergence, but biomass production was reduced only by atrazine and fluridone. Conversely, wheat, cereal rye, barley, oats, and triticale were not affected by soil-applied herbicides. Barley was the only cereal cover crop that showed biomass reduction due to the application of flumioxazin, fluridone, mesotrione,S-metalochlor, and sulfentrazone. In the carryover study, with the exception of crimson clover, Austrian winterpea, cereal rye, hairy vetch, rapeseed, and wheat showed no negative affect on biomass production following a 2×rate of postemergence-applied residual herbicide in corn.

L(3,2,1)-Labeling of the Jahangir Graph

An L(3,2,1)-labeling is a simplified model for the channel assignment problem. It is a natural generalization of the widely studied L(2,1)-labeling. An L(3,2,1)-labeling of a graph G is a function f from the vertex set V(G) to the set of positive integers such that for any two vertices x,y, if d(x,y) = 1, then │f(x) ─ f(y)│≥ 3; if d(x,y) = 2, then f(x) ─ f(y)│≥ 2; if d(x,y) = 3,then │f(x) ─ f(y)│≥ 1. The L(3,2,1)-labeling number K3(G) of G is the smallest positive integer k such that G has an L(3,2,1)-labeling with k as the maximum label. In this paper we determine the L(3,2,1)-labeling number of the Jahangir graph J4,m.

L(2,1)-Edge-Labelings of the Edge-Path-Replacement of a Graph

Two edges [Formula: see text] and [Formula: see text] in a graph [Formula: see text] are said to be adjacent if they have a vertex in common, and distance two apart if they are nonadjacent but both are adjacent to a common edge. An [Formula: see text]-edge-labeling of a graph [Formula: see text] is an assignment of nonnegative integers, called labels, to the edges of [Formula: see text] such that the difference between labels of any two adjacent edges is at least [Formula: see text], and the labels of any two edges that are distance two apart are different. The span of an [Formula: see text]-edge-labeling of a graph [Formula: see text] is the difference between the maximum and minimum labels. The minimum span over all [Formula: see text]-edge-labelings of a graph [Formula: see text] is called the [Formula: see text]-edge-labeling number of [Formula: see text], denoted by [Formula: see text]. For [Formula: see text], the edge-path-replacement of a graph [Formula: see text], denoted by [Formula: see text], is a graph obtained by replacing each edge of [Formula: see text] with a path [Formula: see text] on [Formula: see text] vertices. This paper investigates the [Formula: see text]-edge-labeling number of the edge-path-replacement [Formula: see text] of a graph [Formula: see text] for [Formula: see text]. We get the following main results: [Formula: see text] Let [Formula: see text] be a graph with maximum degree [Formula: see text] and [Formula: see text] be an integer not less than [Formula: see text], then [Formula: see text] if [Formula: see text] is odd, and otherwise [Formula: see text]. [Formula: see text] Let [Formula: see text] be a graph with maximum degree [Formula: see text]. Then [Formula: see text] when [Formula: see text] is even, and [Formula: see text] when [Formula: see text] is odd.

IRIS super-resolution microscopy enables to image multiple protein distributions in a single cell

Cellular phenomena such as cell division and migration are regulated by various proteins. To study the complex cellular systems, super-resolution microscopy that can visualize protein distribution with a resolution of 20-100 nm is useful. But the conventional super-resolution microscopy has a limitation in the number of observable targets due to the number of usable fluorescent dyes (generally two or three). Also the super-resolution microscopy reveals the uneven labeling pattern of antibodies and fluorescent proteins on the target distribution with the high resolution. This means that imaging of the accurate distribution of targets is very difficult with the conventional labeling method. To solve the two problems, we recently have developed a multitarget super-resolution microscopy called image reconstruction by integrating exchangeable single-molecule localization (IRIS) (Kiuchi et al., Nature Methods, 12: 743-746, 2015). In IRIS, exchangeable probes that repeatedly associate with and dissociate from their targets are used for labeling, instead of antibodies and fluorescent proteins. The localization of the binding probe is determined as the central position of the fluorescent speckle with high accuracy. Integration of the positions produces the high resolution image of the target distribution. Washing out the probes and adding new probes one after another allow for the sequential imaging of multiple targets within a single specimen. In addition, the repeated associations of the probes enable to increase the labeling efficiency in the target distribution unlimitedly. To verify the IRIS method, we imaged actin filaments using Lifeact that repeatedly associates with and dissociates from actin filaments. The super-resolved image demonstrated that the labeling density of Lifeact readily reached 60 times the maximum labeling density attainable with antibody binding. For multitarget IRIS imaging, we screened 18 IRIS exchangeable probes out of 46 fragments of 15 cytoskeleton- or focal adhesion-associated proteins. IRIS using these probes discerned the area-specific proximity of actin filaments, microtubules, intermediate filaments and focal adhesions within a single cell (Fig. 1). Thus IRIS approach overcomes the limitation on labeling efficiency and enables to image the multiple target distributions with high fidelity.

Effect of Nozzle Orientation on Dispersion of Aqualuer 20-20 Sprayed by a Truck-Mounted Ultra-Low Volume Sprayer Against Caged Aedes aegypti.

Inconsistencies in efficacy of ultra-low volume (ULV) ground applications in the literature are linked to the lack of adjustments in sprayer parameters. To investigate the effect of nozzle orientation of a truck-mounted ULV sprayer on application efficacy, a study was conducted at St. Johns County Fairground, Elkton, FL, during the summer of 2014. The efficacy was assessed by mortality of caged adult Aedes aegypti, spray deposition, and droplet size spectrum up to 122 m from the spray line. Aqualuer 20-20 (20.6% permethrin active ingredient [AI] and 20% piperonyl butoxide [PBO]) was applied at the maximum label rate with the nozzle pointed 45° upward, horizontal (0°), or 30° downward. Mortality was recorded after 24 h, deposition was determined with fluorometry, and droplets were measured with DropVision. Overall, horizontal nozzle angle spraying Aqualuer 20-20 achieved the highest efficacy followed by a 30° downward angle, while a 45° angle showed the least efficacy in open field tests. The mortality data showed complete mortality from a 0° nozzle up to 122 m from the spray line except for 1 location at 122 m in 1 replication. The mortality from a 30° downward orientation was lower beyond 30 m from the spray line, while the mortality from a 45° upward orientation was low close to the spray line and beyond 30 m. Horizontal orientation had higher deposition than other orientations, but the differences were not significant. There was also no significant difference in droplet spectrum from all orientations.

Comparative study on radiolabeling and biodistribution of core-shell silver/polymeric nanoparticles-based theranostics for tumor targeting

A simple and rapid method for radiolabeling of three types of Ag NPs has been performed using 125I isotope, with high labeling yields, >90% without disturbing the optical properties. All the factors affecting labeling yield were studied. In order to monitor the in-vivo tissue uptake of radiolabeled Ag NPs using γ-rays, Ag-based radioiodo-NPs with a maximum labeling yield were intravenously injected in normal and solid tumor bearing mice. The preliminary biodistribution study revealed that this new radioiodo-NPs have a high affinity to be localized in the tumor site for a long period of time. The reported highly efficient method provides new radiolabeled Ag-based NPs as tumor-specific agents for both diagnostic and therapeutic applications.

Factors influencing the toxicity of Headline® fungicides to terrestrial stage toads.

Amphibians are susceptible to exposure from contaminants via multiple pathways. Pyraclostrobin fungicides have been shown to be toxic to terrestrial amphibians at environmentally relevant concentrations; however, these studies did not account for factors that may influence exposure and effects, such as fungicide formulation, age of the individual, exposure route, and physiological state of the individual. We examined Headline® and Headline AMP® fungicide toxicity to adult Anaxyrus cognatus and Anaxyrus woodhousii by direct overspray, as well as acute toxicity of Headline AMP to juvenile A. cognatus through direct overspray, previously exposed soils, and diet. We also assessed effects of hydration state on fungicide toxicity in juvenile A. cognatus and sublethal effects of fungicide exposure on prey-orientation ability of juvenile A. cognatus. Neither formulation of Headline caused mortality of adult A. cognatus and A. woodhousii at up to 5 times the maximum label rate in North American corn (1052 and 879 mL formulation/ha for Headline AMP and Headline fungicides, respectively, corresponding to 1.52 and 2.2 μg pyraclostrobin/cm2 , respectively). Exposures of juvenile A. cognatus to Headline AMP via direct overspray and previously exposed soils (2 types) resulted in median lethal rate (LR50) values of 2.4, 3.34, and 3.61 μg pyraclostrobin/cm2 , respectively. Dietary Headline AMP exposure was not toxic, prey-orientations were not influenced by exposure, and effects were similar between dehydrated and hydrated treatments (LR50 = 2.4 and 2.3 μg pyraclostrobin/cm2 , respectively). These results, combined with exposure concentrations reported in previous studies, suggest that risk of acute mortality for amphibians in terrestrial environments is low and is dictated by body size and site-specific factors influencing exposure. Environ Toxicol Chem 2017;36:2679-2688. © 2017 SETAC.

Magnetic 99mTc- core-shell of polyethylene glycol/polyhydroxyethyl methacrylate based on Fe3O4 nanoparticles: Radiation synthesis, characterization and biodistribution study in tumor bearing mice

Magnetic nanoparticles (Fe3O4) coated with polyethylene glycol (PEG), (Fe3O4/PEG), were synthesized by chemical co-precipitation of Fe2+/Fe3+ salts by aqueous ammonia in PEG solution. Radiation polymerization of 2-hydroxyethyl methacrylate (HEMA) monomer solution onto Fe3O4/PEG was performed at different doses to synthesize (Fe3O4/PEG)-pHEMA, namely FPH, nanocomposites. Properties of FPH nanocomposites were characterized by FT-IR, XRD, SEM, TEM, DLS, ESR and TGA techniques. The XRD of FPH nanocomposites showed all the peaks of Fe3O4 nanoparticles. SEM was used to assess the surface morphology of FPH. TEM showed that the average diameter of FPH nanocomposites was in the range of 9–40nm. The thermal stability of FPH nanocomposites was higher than that of Fe3O4 and Fe3O4/PEG. Radio-labeling of (Fe3O4/PEG)-pHEMA nanocomposite irradiated at 10kGy (FPH10) with 99mTc was performed using stannous chloride as reducing agent. Factors affecting the labeling yield (%) such as the substrate amount, the amount of reducing agent, the pH of reaction medium, the reaction time and the reaction temperature were investigated. The maximum labeling yield was 93% using 0.25mg of FPH10 at pH 6 and 20min reaction time. The biodistribution study of 99mTc-FPH10 was examined on two groups of ascites and solid tumor bearing mice. The biodistribution results referred that 99mTc-FPH10 was rapidly uptake in tumor sites ascites or solid tumors. The results indicated that FPH nanocomposites could be potentially used for tumor imaging and therapy.

Radiolabeling, quality control, and biological characterization of177 Lu-labeled kanamycin.

Kanamycin is an antibiotic, isolated from Streptomyces kanamyceticus, which is used to treat serious bacterial infections. The fact that the present radioligand 99m Tc-kanamycin used for diagnosis is short-lived, raised a need to label and study kanamycin with one of the most important beta (β) radiation emitting isotope 177 Lu. Labeling yield of 177 Lu-kanamycin was confirmed by different chromatography techniques such as paper chromatography, TLC, HPLC. Several experiments were performed to optimize labeling with changing reaction conditions such as pH, temperature, amount of ligand, and reaction time. In vitro stability analysis was performed incubation with human serum. Electrophoresis analysis was also conducted to determine the charge on 177 Lu-kanamycin. The biodistribution and scintigraphy were performed in normal mice and rabbit, respectively, at different time intervals of postinjection. 177 Lu-kanamycin was prepared with very high yield (~100%), with excellent stability in vivo and in vitro (>99% 6hr postprep.), at pH 7. Maximum labeling was achieved at less reaction time (15min), with maximum conjugation of the ligand (12.5mg) with 177 Lu. Electrophoresis analysis showed net neutral charge. The radioligand showed rapid clearance from body in biodistribution and scintigraphy studies. The preparation 177 Lu-kanamycin could be used as a radio-pharmaceutical for infection imaging purpose, especially when transporting the radioligand to long-range distances.