Povećana isporuka etopozida u Daltonov limfom u miševa pomoću micela s polisorbatom 20

The study evaluates the possibility of enhancing uptake of etoposide (topoisomerase II inhibitor) by tumor when delivered through Polysorbate 20 micelles. The micelle formation was ascertained by determining the critical micellar concentration (CMC) with a du Nouy ring tensiometer and by size measurement using dynamic light scattering. Addition of 5% ethanol decreased the CMC of Polysorbate 20 (from 5.0 x 10-5 to 4.54 x 10-5 mol L-1). Etoposide (ET) and etoposide loaded Polysorbate 20 micelles (EPM) were radiolabeled with 99mTc by the reduction method using stannous chloride. Labeling parameters were optimized to obtain high labeling efficiency. The diethylenetriamine pentaacetic acid and cysteine challenge tests showed very low transchelation of 99mTc-ET and 99mTc-EPM complexes indicating their in vitro stability. The complexes also exhibited serum stability assessed by ascending thin layer chromatography. Subcutaneous injection of EPM resulted in significantly higher tumor uptake (~ 100 folds compared to ET 6 h post injection) (p < 0.001) and prolonged tumor retention. Tumor uptake was also confirmed by gamma imaging studies. EPM exhibited relatively high brain concentrations (~7 fold 24 h post injection) compared to ET, suggesting the potential use of EPM in the treatment of brain malignancies.U radu je proučavan ulazak etopozida (inhibitora topoizomeraze II) u tumorsko tkivo iz micela s polisorbatom 20. Oblikovanje micela je potvrđeno određivanjem kritične micelarne koncentracije (CMC) pomoću du Nouy kružnog tenziometra i mjerenjem veličine čestica metodom rasapa svjetlosti. Dodatak 5% etanola smanjuje CMC polisorbata 20 (od 5,0 x 10-5 do 4,54 x 10-5 mol L-1). Etoposid (ET) i micele etoposida s polisorbatom 20 (EPM) obilježene su radioizotopom 99mTc redukcijom pomoću kositrova klorida. Parameteri markiranja su optimirani. Testovi s dietilentriamin pentaoctenom kiselinom i cisteinom pokazali su vrlo nisko transkeliranje 99mTc-ET i 99mTc-EPM kompleksa, što ukazuje na njihovu stabilnost u uvjetima in vitro. Uzlaznom tankoslojnom kromatografijom dokazana je i stabilnost kompleksa u serumu. Nakon subkutane primjene EPM isporuka etopozida u tumorsko tkivo bila je značajno veća (~ 100 puta u odnosu na ET 6 h poslije injiciranja) (p < 0,001), a dokazano je i produljeno zadržavanje EPM u tumoru. Ulazak u tumor je potvrđen i gama analizom slike. EPM je postigao relativno visoku koncentraciju u mozgu u usporedbi s ET (~ 7 puta veću 24 h poslije injiciranja), zbog čega bi se potencijalno mogao upotrijebiti u terapiji malignih tumora mozga

Steady State Voltage Stability Enhancement Using Shunt and Series FACTS Devices

It is specifically important to focus on voltage stability analysis of the power system to avoid worst case scenarios such as voltage collapse. The purpose of this thesis is to identify methods for enhancing the steady-state voltage stability using FACTS devices and determining their impact on real and reactive power losses, improvement of bus voltage magnitude, and transmission line loadability. To achieve this, FACTS devices such as Static VAR Compensator (SVC), Static Synchronous Compensator (STATCOM), and Thyristor Controlled Series Capacitor (TCSC) are used in the test system as three separate test cases. The results obtained assist in drawing conclusions on the effectiveness of each FACTS devices at generator, load and swing buses, on lines between two load buses, and between a load bus and a generator bus, in terms of metrics such as voltage magnitude profile, PV curves, and active and reactive power losses

Overview of Environmental Control and Life Support Systems in Human Space Missions

This review explores the essential role of Environmental Control and Life Support Systems (ECLSS) in supporting human space missions, particularly those targeting the Moon, Mars, and beyond Earth’s orbit. It presents a detailed analysis of ECLSS subsystems including atmosphere regulation, water reclamation, thermal control, waste handling, and fire safety. Emphasis is placed on the adaptation of these systems to diverse extraterrestrial environments, challenges encountered in extended missions, and recent advancements such as autonomous management and bioregenerative life support. The review concludes with prospects that integrate synthetic biology and artificial intelligence for sustainable space habitation

AV Nodal Reentrant Tachycardia Causing Inappropriate ICD Shocks In A Patient With Arrhythmogenic RV Dysplasia

We report a patient with an implantable cardioverter defibrillator (ICD) for arrhythmogenic right ventricular dysplasia (ARVD) who received inappropriate shocks for atrioventricular node reentry tachycardia (AVRNT). Patient had multiple shocks for tachycardia with EGM characteristics of very short VA interval and CL of 300 msec. An electrophysiologic (EP) study reproducibly induced typical AVNRT with similar features. The slow AV nodal pathway ablation resolved the ICD shocks. Despite increasingly sophisticated discrimination algorithms available in modern ICDs, the ability to differentiate SVT from VT can be challenging. Our patient received inappropriate shocks for AVNRT. When device interrogation alone is not conclusive, an EP study may be necessary to determine the appropriate therapeutic course

Povećana isporuka etopozida u Daltonov limfom u miševa pomoću micela s polisorbatom 20

The study evaluates the possibility of enhancing uptake of etoposide (topoisomerase II inhibitor) by tumor when delivered through Polysorbate 20 micelles. The micelle formation was ascertained by determining the critical micellar concentration (CMC) with a du Nouy ring tensiometer and by size measurement using dynamic light scattering. Addition of 5% ethanol decreased the CMC of Polysorbate 20 (from 5.0 x 10-5 to 4.54 x 10-5 mol L-1). Etoposide (ET) and etoposide loaded Polysorbate 20 micelles (EPM) were radiolabeled with 99mTc by the reduction method using stannous chloride. Labeling parameters were optimized to obtain high labeling efficiency. The diethylenetriamine pentaacetic acid and cysteine challenge tests showed very low transchelation of 99mTc-ET and 99mTc-EPM complexes indicating their in vitro stability. The complexes also exhibited serum stability assessed by ascending thin layer chromatography. Subcutaneous injection of EPM resulted in significantly higher tumor uptake (~ 100 folds compared to ET 6 h post injection) (p < 0.001) and prolonged tumor retention. Tumor uptake was also confirmed by gamma imaging studies. EPM exhibited relatively high brain concentrations (~7 fold 24 h post injection) compared to ET, suggesting the potential use of EPM in the treatment of brain malignancies.U radu je proučavan ulazak etopozida (inhibitora topoizomeraze II) u tumorsko tkivo iz micela s polisorbatom 20. Oblikovanje micela je potvrđeno određivanjem kritične micelarne koncentracije (CMC) pomoću du Nouy kružnog tenziometra i mjerenjem veličine čestica metodom rasapa svjetlosti. Dodatak 5% etanola smanjuje CMC polisorbata 20 (od 5,0 x 10-5 do 4,54 x 10-5 mol L-1). Etoposid (ET) i micele etoposida s polisorbatom 20 (EPM) obilježene su radioizotopom 99mTc redukcijom pomoću kositrova klorida. Parameteri markiranja su optimirani. Testovi s dietilentriamin pentaoctenom kiselinom i cisteinom pokazali su vrlo nisko transkeliranje 99mTc-ET i 99mTc-EPM kompleksa, što ukazuje na njihovu stabilnost u uvjetima in vitro. Uzlaznom tankoslojnom kromatografijom dokazana je i stabilnost kompleksa u serumu. Nakon subkutane primjene EPM isporuka etopozida u tumorsko tkivo bila je značajno veća (~ 100 puta u odnosu na ET 6 h poslije injiciranja) (p < 0,001), a dokazano je i produljeno zadržavanje EPM u tumoru. Ulazak u tumor je potvrđen i gama analizom slike. EPM je postigao relativno visoku koncentraciju u mozgu u usporedbi s ET (~ 7 puta veću 24 h poslije injiciranja), zbog čega bi se potencijalno mogao upotrijebiti u terapiji malignih tumora mozga

A Validated Stability-Indicating RP-UPLC Method for Simultaneous Determination of Desloratadine and Sodium Benzoate in Oral Liquid Pharmaceutical Formulations

A novel, sensitive and selective stability-indicating gradient reverse phase ultra performance liquid chromatographic method was developed and validated for the quantitative determination of desloratadine and sodium benzoate in pharmaceutical oral liquid formulation. The chromatographic separation was achieved on Acquity BEH C8 (100 mm × 2.1 mm) 1.7 μm column by using mobile phase containing a gradient mixture of solvent A (0.05 M KH2PO4 and 0.07 M triethylamine, pH 3.0) and B (50:25:25 v/v/v mixture of acetonitrile, methanol and water) at flow rate of 0.4 mL/min. Column temperature was maintained at 40°C and detection was carried out at a wavelength of 272 nm. The described method shows excellent linearity over a range of 0.254 μg/mL to 76.194 μg/mL for desloratadine and 1.006 μg/mL to 301.67 μg/mL for sodium benzoate. The correlation coefficient for desloratadine and sodium benzoate was more than 0.999. To establish stability-indicating capability of the method, drug product was subjected to the stress conditions of acid, base, oxidative, hydrolytic, thermal and photolytic degradation. The degradation products were well resolved from desloratadine and sodium benzoate. The developed method was validated as per international ICH guidelines with respect to specificity, linearity, LOD, LOQ, accuracy, precision and robustness