No abstract

Many groups have reported the adsorption or retention of 99m Tcradiopharmaceuticals on injection vials and disposable plastic syringes. Such an enormously high loss of radioactivity would result in poor images, radiation exposure, waste, and economic burdens. We therefore decided to investigate the extent of adsorption or retention of several 99m Tc-radiopharmaceuticals on injection vials, rubber stoppers, and plastic syringes. These radiopharmaceuticals are produced as lyophilized kits in our department and supplied to various hospitals practicing nuclear medicine in Pakistan. Methods: A vial containing lyophilized material was reconstituted with 3 mL of freshly eluted Na 99m TcO 4 . A 1-mL aliquot of the resulting solution was withdrawn into a syringe at 0.25, 0.5, 1, 3, and 5 h after preparation. All preparations were stored at room temperature (;22°C). After each withdrawal, the vial was reweighed and the activity remaining in the vial was measured using a radioisotope calibrator. The sample was reinjected into the vial. From the original weight and activity of solution in the vial, the initial activity per gram was calculated. From the weight and activity remaining in the vial after withdrawal of the sample, the activity per gram of the sample was calculated. From the difference between the initial activity per gram and the activity per gram of the sample, the percentage of 99m Tc adsorbed on the vial was calculated. All preparations were kept in the syringe for 15 min, and the activity was measured before and after the syringe was emptied. The needle and plunger of the syringe were separated, and activity in the needle and plunger was also measured. Results: The labeling efficiency of all radiopharmaceuticals used during these studies was more than 95%. In most cases, the activity of 99m Tc found on the rubber stopper was less than 1%. Adsorption of 99m Tc onto vials increased gradually with storage time. Adsorption was minimal at the initial stages, whereas maximum retention was noted after 5 h. Nearly 5% adsorption of activity was observed after 5 h of storage time on vials of sestamibi, mercaptoacetyltriglycine, dextran, ciprofloxacin, and dimercaptosuccinic acid (III and V). Retention of activity on needles ranged from 1% to 2% for all preparations studied. Plungers did not show any significant retention of radioactivity; in most cases, retention was less than 0.5%. The maximum retention of radioactivity on plastic syringe bodies was more than 3% for sestamibi, dimercaptosuccinic acid, dextran, pyrophosphate, and phytate. Conclusion: The results revealed that losses of radioactivity from 99m Tc-radiopharmaceuticals in these objects (glass vial, rubber stopper, plastic syringes, plungers, and needles) are not alarming in our setup.

<p></p><p>One of the main reasons of rapidly growing cases of COVID-19 pandemic is the unavailability of approved therapeutic agents. Therefore, it is urgently required to find out the best drug by all means. Aim of the current study is to test the anti-viral drug potential of many of the available olive and turmeric compounds that can be used as potential inhibitors against one of the target proteins of SARS-nCoV2 named Main protease (Mpro/3CLpro). Molecular docking of thirty olive and turmeric compounds with target protein was performed using Molecular Operating Environment (MOE) software, out of these 19 ligands were selected for redocking using PyRx to validate MOE results and to determine the best ligand-protein interaction energies. Molecular dynamics simulation was performed on best 7 docked complexes by NAMD/VMD to determine the stability of the ligand-protein complex. Out of the thirty drug agents, 6 ligands do not follow the Lipinski rule of drug likeliness by violating two or more rules while remaining 24 obey the rules and included for the downstream analysis. We found that Demethyloleoeuropein, Oleuropein, Rutin, Neuzhenide, Luteolin-7-rutinoside, Curcumin and Tetrehydrocurcumin gave best docking score and form much stable complexes during simulation. Our predictions suggest that these ligands have the potential inhibitory effects on Mpro of SARS-nCoV2, so, these herbal plants would be helpful in harnessing COVID-19 infection as home remedy with no serious known side effects. Further, in-vivo experimental studies are needed to validate the inhibitory properties of these compounds against the current and other target proteins in SARS-nCoV2.<b></b></p><br><p></p>