المؤلفون: Pipatpolkai, Tanadet, Usher, S. G., Vedovato, N., Ashcroft, F. M., Stansfeld, P. J.

المصدر: Journal of Physiology. 600(20):4503-4519

مصطلحات موضوعية: ATP-sensitive potassium channel, molecular dynamics, phosphatidylinositol 4, 5-bisphosphate, Adenosine Triphosphate, Amino Acids, Humans, Infant, Newborn, Phosphatidylinositol 4, 5-Diphosphate, Phosphatidylinositols, Potassium, Potassium Channels, Inwardly Rectifying, adenosine triphosphate sensitive potassium, amino acid, arginine, lysine, 5 bisphosphate, potassium channel, unclassified drug, inwardly rectifying potassium channel, phosphatidylinositol, amino acid substitution, Article, binding affinity, binding competition, binding site, controlled study, diabetes mellitus, electrophysiology, fluorometry, gene mutation, human, hydrogen bond, mutational analysis, patch clamp technique, prediction, protein binding, protein protein interaction, spectrofluorometry, wild type, metabolism, newborn, physiology

الوصف: Abstract: ATP-sensitive potassium (KATP) channels couple the intracellular ATP concentration to insulin secretion. KATP channel activity is inhibited by ATP binding to the Kir6.2 tetramer and activated by phosphatidylinositol 4,5-bisphosphate (PIP2). Here, we use molecular dynamics simulation, electrophysiology and fluorescence spectroscopy to show that ATP and PIP2 occupy different binding pockets that share a single amino acid residue, K39. When both ligands are present, simulations suggest that K39 shows a greater preference to co-ordinate with PIP2 than with ATP. They also predict that a neonatal diabetes mutation at K39 (K39R) increases the number of hydrogen bonds formed between K39 and PIP2, potentially accounting for the reduced ATP inhibition observed in electrophysiological experiments. Our work suggests that PIP2 and ATP interact allosterically to regulate KATP channel activity. (Figure presented.). Key points: The KATP channel is activated by the binding of phosphatidylinositol 4,5-bisphosphate (PIP2) lipids and inactivated by the binding of ATP. K39 has the potential to bind to both PIP2 and ATP. A mutation to this residue (K39R) results in neonatal diabetes. This study uses patch-clamp fluorometry, electrophysiology and molecular dynamics simulation. We show that PIP2 competes with ATP for K39, and this reduces channel inhibition by ATP. We show that K39R increases channel affinity to PIP2 by increasing the number of hydrogen bonds with PIP2, when compared with the wild-type K39. This therefore decreases KATP channel inhibition by ATP.

وصف الملف: print

الوصول الحر: https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-327277Test
https://doi.org/10.1113/JP283345Test

المؤلفون: Ahmed Saleh, Nermin Victor, Amira Elkosasy

المصدر: Archives of Pharmaceutical Sciences Ain Shams University, Vol 6, Iss 2, Pp 253-263 (2022)

مصطلحات موضوعية: baricitinib, covid-19, spectrofluorometry, eco-scale, gapi, Therapeutics. Pharmacology, RM1-950

الوصف: FDA approved Baricitinib for the treatment of COVID-19 for hospitalized patients. So far, there is no previously published spectrofluorometric method for the analysis of Baricitinib. To this purpose, a first spectrofluorometric method with environmentally friendly approach for the determination of baricitinib in its pure and tablet dosage form has been developed and validated. The spectrum of BCT in methanol shows λex at 224 nm and λem at 414 nm. Calibration graph was found to be linear (r= 0.9998) over the concentration range of (0.500-1.000 μg/mL). The proposed method was validated with percentage recovery of 100.32 % ± 1.284 and relative standard deviation of less than 2.00 demonstrated the accuracy and precision of the method. The method was found to have a LOD of 0.102 μg and a LOQ of 0.309 μg⁄mL respectively. The study established showed that the proposed method can be adopted in the routine analysis since there is no specific monograph available in official pharmacopoeia up to this date for determination of Baricitinib.

وصف الملف: electronic resource

العلاقة: https://aps.journals.ekb.eg/article_287097.htmlTest; https://doaj.org/toc/2356-8380Test; https://doaj.org/toc/2356-8399Test

الوصول الحر: https://doaj.org/article/c2f10d40789e434b8b15e8610b7763c0Test

المؤلفون: Amr A. Abd-Elghany, A. M. M. Yousef

المصدر: International Journal of Biomedicine, Vol 12, Iss 4, Pp 560-566 (2022)

مصطلحات موضوعية: electroendocytosis, asymmetric bipolar electrical impulses, receptor-mediated endocytosis, spectrofluorometry, u251mg cells, Medicine

الوصف: Electric and electromagnetic pulses have been shown to enhance the endocytosis rate, with all-or-nothing responses beyond a field strength threshold and linear responses as a function of field strength and treatment duration utilizing bipolar symmetrical and monopolar pulses, respectively. Malignant glioma (MG) is resistant to chemotherapy. The present study looked for a new electrical impulse that can aid electrochemotherapy to deliver anticancer drugs while using less electrical energy. Bipolar asymmetric electric pulses were applied to U251MG cells suspended in physiologically conductive media in the presence of molecular probes, including Bleomycin. The delivered electric pulses with a pulse duration range of 180-500 µs and a frequency range of 100-400 Hz had a low field intensity ranging from 1.5 V/cm to 7.3 V/cm. Spectrophotometric and spectrofluorometric measurements were used to investigate the impact of these variables on cancer cell survival and the molecular probe uptake induced by the electric pulses. An all-or-nothing response was observed above a specified threshold of electric field intensity of 4 V/cm. This threshold was unaffected by changes in repetition frequency or pulse duration. It was not a temperature effect that caused the molecular probe uptake to increase. When bipolar asymmetric electric pulses were applied just before electroporation, the effectiveness of the cytotoxic impact of bleomycin was increased from 80%, when employing electroporation pulses alone, to 100%.

وصف الملف: electronic resource

العلاقة: http://www.ijbm.org/articles/i48/ijbm_12Test(4)_oa6.pdf; https://doaj.org/toc/2158-0510Test; https://doaj.org/toc/2158-0529Test

الوصول الحر: https://doaj.org/article/6455d5ee7de9429fa9411ac9ed527759Test

المؤلفون: Safronov, N. E., Kostova, I. P., Palafox, M. A., Belskaya, N. P.

المصدر: International Journal of Molecular Sciences

مصطلحات موضوعية: 1,2,3-TRIAZOLES, CARBOXYLIC ACID, DIMER, FLUORESCENCE, PKA, TDDFT, 1,2,3 TRIAZOLE 4 CARBOXYLIC ACID, ANION, CARBOXYLIC ACID DERIVATIVE, DIMETHYL SULFOXIDE, DIOXANE, METHANOL, SODIUM, UNCLASSIFIED DRUG, WATER, SODIUM CHLORIDE, SOLVENT, TRIAZOLE DERIVATIVE, ARTICLE, CARBON NUCLEAR MAGNETIC RESONANCE, CHEMICAL STRUCTURE, CONTROLLED STUDY, DENSITY FUNCTIONAL THEORY, IONIZATION, MOLECULAR INTERACTION, NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY, PROTON NUCLEAR MAGNETIC RESONANCE, QUANTUM CHEMISTRY, SPECTROFLUOROMETRY, ULTRAVIOLET VISIBLE SPECTROSCOPY

الوصف: The peculiarities of the optical properties of 2-aryl-1,2,3-triazole acids and their sodium salts were investigated in different solvents (1,4-dioxane, dimethyl sulfoxide DMSO, methanol MeOH) and in mixtures with water. The results were discussed in terms of the molecular structure formed by inter- and intramolecular noncovalent interactions (NCIs) and their ability to ionize in anions. Theoretical calculations using the Time-Dependent Density Functional Theory (TDDFT) were carried out in different solvents to support the results. In polar and nonpolar solvents (DMSO, 1,4-dioxane), fluorescence was provided by strong neutral associates. Protic MeOH can weaken the acid molecules’ association, forming other fluorescent species. The fluorescent species in water exhibited similar optical characteristics to those of triazole salts; therefore, their anionic character can be assumed. Experimental 1H and 13C-NMR spectra were compared to their corresponding calculated spectra using the Gauge-Independent Atomic Orbital (GIAO) method and several relationships were established. All these findings showed that the obtained photophysical properties of the 2-aryl-1,2,3-triazole acids noticeably depend on the environment and, therefore, are good candidates as sensors for the identification of analytes with labile protons. © 2023 by the authors. ; BG-RRP-2.004-0004-C01 ; The administrative support received by the European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria, project No. BG-RRP-2.004-0004-C01 is greatly acknowledged.

وصف الملف: application/pdf

العلاقة: Safronov, NE, Kostova, IP, Palafox, MA & Belskaya, NP 2023, 'Combined NMR Spectroscopy and Quantum-Chemical Calculations in Fluorescent 1,2,3-Triazole-4-carboxylic Acids Fine Structures Analysis', International Journal of Molecular Sciences, Том. 24, № 10, 8947. https://doi.org/10.3390/ijms24108947Test; Safronov, N. E., Kostova, I. P., Palafox, M. A., & Belskaya, N. P. (2023). Combined NMR Spectroscopy and Quantum-Chemical Calculations in Fluorescent 1,2,3-Triazole-4-carboxylic Acids Fine Structures Analysis. International Journal of Molecular Sciences, 24(10), [8947]. https://doi.org/10.3390/ijms24108947Test; Final; All Open Access, Gold, Green; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85160376599&doi=10.3390%2fijms24108947&partnerID=40&md5=c71224dcfc837a512239ec8a77fdb623Test; https://www.mdpi.com/1422-0067/24/10/8947/pdf?version=1684400993Test; http://elar.urfu.ru/handle/10995/130516Test; 85160376599; 000998011100001

الإتاحة: https://doi.org/10.3390/ijms24108947Test
http://elar.urfu.ru/handle/10995/130516Test
https://www.mdpi.com/1422-0067/24/10/8947/pdf?version=1684400993Test

المؤلفون: Gour, N., Kshtriya, V., Khatun, S., Bandyopadhyay, S., Ghosh, R., Koshti, B., Singh, R., Haque, A., Bhatia, D., Joshi, K. B., Boukhvalov, D. W., Nath, S., Rengan, A. K.

المصدر: Chemistry – An Asian Journal ; Chemistry - An Asian Journal

مصطلحات موضوعية: ANTICANCER PROPERTIES, CELL IMAGING, CHARGE TRANSFER, COMPUTATIONAL MODELING, FLUORESCENT DYE, SELF-ASSEMBLY, CELL CULTURE, CELLS, COMPUTATION THEORY, COMPUTERIZED TOMOGRAPHY, FLUORESCENCE, SELF ASSEMBLY, BIOLOGICAL EVALUATION, CELL VIABILITY, COLOR CHANGING, COMPUTATIONAL MODELLING, FLUORESCENT DYES, PHOTOPHYSICAL PROPERTIES, PHOTOPHYSICAL STUDIES, SELF-ASSEMBLING, SOLVENT, ANIMAL, CELL LINE, CELL SURVIVAL, MOUSE, PROCEDURES, SPECTROFLUOROMETRY, ANIMALS, MICE, SOLVENTS

الوصف: We report the photophysical properties, self-assembly and biological evaluation of an isothiazolanthrone-based dye, 7-amino-6H-anthra[9,1-cd]isothiazol-6-one (AAT), which reveals anticancer properties and can be potentially used as dye for monitoring cell viability. The solvent-dependent photophysical studies suggest that the emission of AAT is sensitive to environment polarity due to which interesting changes in the colored emission may be observed owing to the charge transfer (CT) processes. AAT also self-assembles to tree-like branched morphologies and produce, a greenish emission inside the cells when imaged after short interval (15 mins) of incubation while a red fluorescence could be noted after 24 h. Interestingly, AAT also produce differential emission inside mouse normal cells as compared to its cancer cell lines since it possess anticancer activity. The experimental observations were also validated theoretically via computational modeling. © 2023 Wiley-VCH GmbH. ; Indian Council of Medical Research, ICMR: 45/13/2020‐/BIO/BMS; Science and Engineering Research Board, SERB: EMR/2016/003186, SPG/2021/000521; Ministry of Education and Science of the Russian Federation, Minobrnauka: FEUZ‐2023‐0013 ; NG, greatly acknowledge support from the SERB research grants (EMR/2016/003186; SPG/2021/000521) for funding. VK is grateful to ICMR, India for providing financial support under the Senior Research Fellowship No. 45/13/2020‐/BIO/BMS. BK thanks SHODH fellowship for funding and Indrashil University for infrastructure support. RS thanks CSIR‐UGC for the pre‐doctoral senior research fellowship. KBJ acknowledges Sophisticated Instrument Centre (SIC)‐Dr. Harisingh Gour Central University Sagar, India for AFM facility. DWB acknowledged support Ministry of Science and Higher Education of the Russian Federation (through the basic part of the government mandate, Project No. FEUZ‐2023‐0013) and Jiangsu Innovative and Entrepreneurial Talents Project. NG thanks Dr. Abhijit Patra, Mr. Subhadeep Das and Mr. Subhankar Kundu, ...

وصف الملف: application/pdf

العلاقة: Gour, N, Kshtriya, V, Khatun, S, Bandyopadhyay, S, Ghosh, R, Koshti, B, Singh, R, Haque, A, Bhatia, D, Joshi, KB, Boukhvalov, DW, Nath, S & Rengan, AK 2023, 'An Isothiazolanthrone‐Based Self‐Assembling Anticancer Color‐Changing Dye for Concurrent Imaging and Monitoring of Cell Viability', Chemistry - An Asian Journal, Том. 18, № 9, e202300044. https://doi.org/10.1002/asia.202300044Test; Gour, N., Kshtriya, V., Khatun, S., Bandyopadhyay, S., Ghosh, R., Koshti, B., Singh, R., Haque, A., Bhatia, D., Joshi, K. B., Boukhvalov, D. W., Nath, S., & Rengan, A. K. (2023). An Isothiazolanthrone‐Based Self‐Assembling Anticancer Color‐Changing Dye for Concurrent Imaging and Monitoring of Cell Viability. Chemistry - An Asian Journal, 18(9), [e202300044]. https://doi.org/10.1002/asia.202300044Test; Final; All Open Access, Green; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85151455872&doi=10.1002%2fasia.202300044&partnerID=40&md5=d82c9296a0a8534ce2c01e42b6b155aaTest; https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c755ad567dfe0f83ec6324/original/self-assembly-and-photophysical-studies-of-an-unusual-red-colored-dye-which-show-green-fluorescence-in-cell-imaging.pdfTest; http://elar.urfu.ru/handle/10995/130362Test; 85151455872

الإتاحة: https://doi.org/10.1002/asia.202300044Test
http://elar.urfu.ru/handle/10995/130362Test
https://chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c755ad567dfe0f83ec6324/original/self-assembly-and-photophysical-studies-of-an-unusual-red-colored-dye-which-show-green-fluorescence-in-cell-imaging.pdfTest

المؤلفون: V. V. Garkavenko, P. M. Balashova, L. A. Shapiro, V. V. Salmin, В. В. Гарькавенко, П. М. Балашова, Л. А. Шапиро, В. В. Салмин

المصدر: National Journal glaucoma; Том 22, № 4 (2023); 15-25 ; Национальный журнал Глаукома; Том 22, № 4 (2023); 15-25 ; 2311-6862 ; 2078-4104

مصطلحات موضوعية: ишемия зоны лимба, prostaglandin analogs, spectrofluorometry, limbal stem cell deficiency, limbal ischemia, аналоги простагландинов, спектрофлуориметрия, дефицит лимбальных стволовых клеток

الوصف: PURPOSE. Comparative assessment of the spectrofluorimetric parameters of the limbus area in patients with primary open-angle glaucoma (POAG) receiving various molecules of prostaglandin analogues topically.METHODS. The study included 129 patients (129 eyes) with newly diagnosed primary open-angle glaucoma who were randomized into four groups depending on the prostaglandin analogue they used for one month. The control group consisted of patients who were prescribed a non-selective beta-blocker (timolol). Patients underwent a comprehensive ophthalmological examination and spectrofluorimetric study of the limbus area.RESULTS. In all studied groups, the achieved hypotensive effect after one month of instillations was 30.6–34.5% of the baseline intraocular pressure (IOP) level. Stabilization of glaucomatous optic neuropathy was determined in all study groups regardless of the stage of POAG with varying degrees of significance. The most pronounced ischemic effect on the limbus area was recorded in patients with moderate POAG using travoprost (increase in fluorescence intensity of 0.14; p=0.018), advanced POAG — using bimatoprost (increase in fluorescence intensity of 0.141; p<0.0001). Latanoprost had a lesser effect on ischemia of the limbal area — increase in fluorescence intensity of 0.124 (p=0.043) and 0.104 (p<0.001) in moderate and advanced stages, respectively. In the control group in all examined patients the difference in fluorescence indices was insignificant, which may indicate a minimal effect of timolol on ischemia of the limbus area.CONCLUSION. Spectrofluorometric indicators of the limbal area reflect the ischemic effect of all molecules within the prostaglandin analogue class, while the use of beta-blockers causes a minimal effect on ischemia. The use of any prostaglandin analogues in patients with advanced POAG leads to more pronounced ischemia of the limbal area than in eyes with moderate stage, which suggests a greater tendency to scarring of the filtering bleb after hypotensive interventions. ...

وصف الملف: application/pdf

العلاقة: https://www.glaucomajournal.ru/jour/article/view/425/435Test; https://www.glaucomajournal.ru/jour/article/downloadSuppFile/425/135Test; Katsanos A., Riva I., Bozkurt B., Holló G. et al. A new look at the safety and tolerability of prostaglandin analogue eyedrops in glaucoma and ocular hypertension. Expert Opinion on Drug Safety 2022; 21(4):525-539. https://doi.org/10.1080/14740338.2022.1996560Test; Алексеев И. Б., Волкова А. В., Алексеева Л. И. Особенности терапии глаукомы аналогами простагландинов в современных реалиях. РМЖ Клиническая офтальмология 2022; 22(3):175-180. https://doi.org/10.32364/2311-7729-2022-22-3-175-180Test; Петров С.Ю., Волжанин А.В., Кравчик М.В. и др. Влияние тафлупроста на суточные колебания офтальмотонуса при первичной открытоугольной глаукоме. Национальный журнал глаукома 2018; 17(4):91-96. https://doi.org/10.25700Test/ NJG.2018.04.08; Астахов Ю.С., Нечипоренко П.А. Аналоги простагландинов: прошлое, настоящее и будущее. Офтальмологические ведомости 2017; 10(1):40-52. https://doi.org/10.17816/OV10140-52Test; Еричев В.П. Простагландины в офтальмологии. Вестник офтальмологии 2022; 138(1):107-114. https://doi.org/10.17116/oftalma2022138011107Test; Thelen U. Treatment of Primary Open-Angle Glaucoma and Ocular Hypertension with Preservative-Free Tafluprost-Timolol Fixed-Dose Combination versus Preservative-Free Latanoprost-Timolol Fixed-Dose Combination Therapy: Real-World Experience. Journal of Ophthalmology and Research 2022; 5(1):24-28. https://doi.org/10.26502/fjor.2644-00240054Test; Казанова С.Ю. Побочные эффекты аналогов простагландинов, используемых в офтальмологической практике. Российский офтальмологический журнал 2021; 14(2):85-89. https://doi.org/10.21516/2072-0076-2021-14-2-85-89Test; Hornubia F., Garcia-Sanhez J., Polo V., Martı´nez de la Casaet J. M. et al. Conjunctival hyperaemia with the use of latanoprost versus other prostaglandin analogues in patients with ocular hypertension or glaucoma: a meta-analysis of randomised clinical trials. Br J Ophthalmol 2009; 93(3):316-321. https://doi.org/10.1136/bjo.2007.135111Test; Shen S.R., Fleming G.P., Jain Sh.G., Roberts C.J. A Review of Corneal Biomechanics and Scleral Stiffness in Topical Prostaglandin Analog Therapy for Glaucoma. Current Eye Research 2022:1-10. https://doi.org/10.1080/02713683.2022.2099903Test; Steensberg A.T., Müllertz O.O., Virgili G, Azuara-Blanco A. et al. Evaluation of generic versus original prostaglandin analogues in the treatment of glaucoma: a systematic review and meta-analysis. Ophthalmology Glaucoma 2020; 3(1):51-59. https://doi.org/10.1016/j.ogla.2019.10.002Test. Epub 2019 Nov 2; Lin L., Zhao Y.J., Chew P.T.K., Sng Ch. C.A., etal. Comparative efficacy and tolerability of topical prostaglandin analogues for primary open-angle glaucoma and ocular hypertension. Annals of Pharmacotherapy 2014; 48(12):1585-1593. https://doi.org/10.1177/1060028014548569Test; European Glaucoma Society. Terminology and guidelines for glaucoma. 4th edition ed: Savona, Italy, PubliComm; 2014. 72.; Ishida A., Miki T., Naito T., Ichioka Sh. et al. Surgical Results of Trabeculectomy among Groups Stratified by Prostaglandin-Associated Periorbitopathy Severity. Ophthalmology 2022. https://doi.org/10.1016/j.ophtha.2022.10.024Test; Lin Z., He H., Zhou T., Liu X. et al. A mouse model of limbal stem cell deficiency induced by topical medication with the preservative benzalkonium chloride. Investigative ophthalmology & visual science 2013; 54(9):6314-6325. https://doi.org/10.1167/iovs.12-10725Test; Mastropasqua R., Agnifili L., Fasanella V., Curcio C. et al. Corneoscleral limbus in glaucoma patients: in vivo confocal microscopy and immunocytological study. Investigative ophthalmology & visual science 2015; 56(3):2050-2058. https://doi.org/10.1167/iovs.14-15890Test; Güçlü H., Çınar A.K., Çınar A.C., Akaray İ. et al. Corneal epithelium and limbal region alterations due to glaucoma medications evaluated by anterior segment optic coherence tomography: a case-control study. Cutaneous and Ocular Toxicology 2021; 40(2):85-94. https://doi.org/10.1080/15569527.2021.1902341Test; Нероев В.В., Гарькавенко В.В., Салмин В.В. Спектрофлуориметрическое исследование зоны лимба у пациентов с первичной открытоугольной глаукомой. Российский офтальмологический журнал 2021; 14(4):60-64. https://doi.org/10.21516/2072-0076-2021-14-4-60-64Test; Vladimirova E.S., Salmin V.V., Salmina A.B., et al. Fluorescence diagnosis of the status of the human lens in vivo. Journal of Applied Spectroscopy 2012; 79(1):126-130. https://doi.org/10.20333/25000136-2014-1-39-43Test; Salmin V.V., Lazarenko V.I., Salmina A.B., Hovalyg M.Sh., Vladimirova E.S. Diagnostics of the cornea pathology by the laser-fluorescence spectroscopy method. Journal of Applied Spectroscopy 2012; 4:646-650. https://doi.org/10.1007/s10812-012-9649-4Test; Владимирова Е.С., Салмин В.В., Салмина А.Б. Флуоресцентная диагностика состояния хрусталика человека in vivo. Журнал прикладной спектроскопии 2012; 79(1):136-140.; Salmin V., Gar’kavenko V., Levchenko J. et al. UVA-induced autofluorescence spectroscopy in ophthalmology. In: Asia Communications and Photonics Conference 2014; OSA Technical Digest (online), paper ATh3A.203. https://doi.org/10.1364/ACPC.2014.ATh3A.203Test; Нероев В.В., Гарькавенко В.В., Шапиро Л.А., Салмин В.В. Оценка состояния электрогенеза сетчатки при ультрафиолетовом спектрофлуориметрическом исследовании глаза. Российский офтальмологический журнал 2020; 13(2):41-44. https://doi.org/10.21516/2072-0076-2020-13-2-41-44Test; Гарькавенко В.В., Салмин В.В., Лазаренко В.И. и др. Определение тактики хирургии катаракты на основании данных спектрофлуориметрического исследования хрусталика. Российский офтальмологический журнал 2017; 10(4):16-19. https://doi.org/10.21516/2072-0076-2017-10-4-16-19Test; https://www.glaucomajournal.ru/jour/article/view/425Test

الإتاحة: https://doi.org/10.53432/2078-4104-2023-22-4-15-25Test
https://doi.org/10.1080/14740338.2022.1996560Test
https://doi.org/10.32364/2311-7729-2022-22-3-175-180Test
https://doi.org/10.17816/OV10140-52Test
https://doi.org/10.17116/oftalma2022138011107Test
https://doi.org/10.26502/fjor.2644-00240054Test
https://doi.org/10.21516/2072-0076-2021-14-2-85-89Test
https://doi.org/10.1136/bjo.2007.135111Test
https://doi.org/10.1080/02713683.2022.2099903Test
https://doi.org/10.1016/j.ogla.2019.10.002Test

المؤلفون: Butina, Karen, Lantz, L., Choong, Ferdinand X., Tomac, Ana, Shirani, H., Löffler, Susanne, Nilsson, Karin Peter R., Richter-Dahlfors, Agneta

المصدر: ChemBioChem. 23(11)

مصطلحات موضوعية: bacterial detection, fluorescence microscopy, fluorescence spectroscopy, optotracers, real-time monitoring, adult, area under the curve, article, bacterium detection, conformation, cross correlation, fluorescence intensity, nonhuman, quantitative analysis, spectrofluorometry, Staphylococcus aureus, bacterium, fluorescence resonance energy transfer, Bacteria

الوصف: Optotracers are conformation-sensitive fluorescent tracer molecules that detect peptide- and carbohydrate-based biopolymers. Their binding to bacterial cell walls allows selective detection and visualisation of Staphylococcus aureus (S. aureus). Here, we investigated the structural properties providing optimal detection of S. aureus. We quantified spectral shifts and fluorescence intensity in mixes of bacteria and optotracers, using automatic peak analysis, cross-correlation, and area-under-curve analysis. We found that the length of the conjugated backbone and the number of charged groups, but not their distribution, are important factors for selective detection of S. aureus. The photophysical properties of optotracers were greatly improved by incorporating a donor-acceptor-donor (D-A-D)-type motif in the conjugated backbone. With significantly reduced background and binding-induced on-switch of fluorescence, these optotracers enabled real-time recordings of S. aureus growth. Collectively, this demonstrates that chemical structure and photophysics are key tunable characteristics in the development of optotracers for selective detection of bacterial species.

وصف الملف: print

الوصول الحر: https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-322569Test
https://doi.org/10.1002/cbic.202100684Test

المؤلفون: Heba Samir Elama, Shereen M. shalan, Yasser El-Shabrawy, Manal I. Eid, Abdallah M. Zeid

المصدر: Royal Society Open Science, Vol 9, Iss 7 (2022)

مصطلحات موضوعية: tadalafil, alfuzosin, lower urinary tract symptoms, spectrofluorometry, biological samples, Science

الوصف: A facile, accurate, eco-friendly and sensitive spectrofluorometric method was evolved to assay alfuzosin hydrochloride (AFH) and tadalafil (TDF) in different matrices. Such a co-administered combination is clinically used for the treatment of lower urinary tract symptoms. Both compounds are characterized by their native fluorescence spectra upon excitation at specific wavelengths. Their characteristic fluorescence spectra were used for sensitive assay of the studied analytes in tablets and human biological samples. The assay principle is based on first-order synchronous spectrofluorometric scan using Δλ = 60 nm in which AFH peaks were recorded at 366 nm. Meanwhile, TDF measurements were recorded at 293 nm in the same scans without overlap with AFH spectra. Recent analytical chemistry trends were implemented to lessen occupational and environmental perils, using ethanol as a diluting solvent for method optimization and application. Linearity ranges were 5.0–90.0 and 10.0–100.0 ng ml−1 for AFH and TDF, respectively in their raw materials with average % recoveries of 100.44% and 99.73% in raw materials, 100.15% and 100.20% in spiked plasma, and 97.14% and 99.99% in spiked urine. The proposed method was successfully applied to Prostetrol and Starkoprex commercial tablets with no interference with common tablet additives.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2054-5703Test

الوصول الحر: https://doaj.org/article/d65c18dc3e0a430b9bf90833cf731c2cTest

المؤلفون: Ahmed K. Alyan, Rasha S. Hanafi, Mohamed Z. Gad

المصدر: Journal of Advanced Research, Vol 27, Iss , Pp 1-10 (2021)

مصطلحات موضوعية: Point-of-care testing, Spectrofluorometry, Hydrogen sulphide, Biomarker, Human plasma, Myocardial infarction, Medicine (General), R5-920, Science (General), Q1-390

الوصف: Introduction: Hydrogen sulphide (H2S) is one of the gasotransmitters that was reported to have a cardioprotective effect at its physiological levels in blood. Previous determinations of H2S levels in cardiovascular disease (CVD) patients suffered from diversity of analytical methods, different targeted chemical forms of the gas, and multitude of matrices assessed.Objectives: In this study, a comparative biological sample preparation study is detailed for optimum selective determination of the unionized form of H2S in blood of CVD patients using a new in-house POCT portable spectrofluorometer together with a Reagent-Analyser system.Methods: Dansyl azide was synthesized to react with hydrogen sulfide in biological matrix to produce the fluorescent dansyl amide. Fluorescence was measured at λex 340 nm and λem 517 nm in the new in-house POCT portable spectrofluorometer. The method was validated according to ICH guidelines. Several blood sample treatments and reaction protocols were compared to achieve maximum fluorescence yield.Results: The H2S Analyser was verified in comparison to a benchtop spectrofluorometer where linearity was confirmed in the range of 3–300 μM, LOD being 1 μM, at λex 340 nm and λem 517 nm. Sample treatment involving blood centrifugation followed by addition of reagent on plasma produced maximum fluorescence yield. Analysis of blood samples of myocardial infarction (MI) patients and controls showed elevated levels of H2S in MI patients (28 μM ± 1.111) vs. controls (23 μM ± 1.036) at p = 0.0015.Conclusion: The study is novel in being a POCT approach for selective determination of H2S molecular form in plasma after simple optimized sample treatment. The study confirms that MI is associated with H2S elevated levels up to 10 hours from emergence of symptoms.

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2090123219301882Test; https://doaj.org/toc/2090-1232Test

الوصول الحر: https://doaj.org/article/efcbc16443f54067a3c263df910f9895Test

المؤلفون: T. A. Yatsenko, S. M. Kharchenko

المصدر: Biotechnologia Acta, Vol 13, Iss 6, Pp 50-57 (2020)

مصطلحات موضوعية: plasminogen, rabbit polyclonal antibodies, affinity chromatography, elisa, western blotting, fitc-coupling, flow cytometry, spectrofluorometry., Biotechnology, TP248.13-248.65

الوصف: The plasminogen/plasmin system plays a crucial role in fibrinolysis and regulation of cell functions in a wide range of normal and pathological processes. Investigation of plasminogen/plasmin functions requires the availability of well-characterized and effective molecular tools, such as antibodies. In the present work, the isolation and characterization of rabbit polyclonal antibodies against human plasminogen are described and approaches for the identification of plasminogen and its fragments using the purified antibodies are demonstrated. For the antibodies isolation, standard animal immunization and blood collection procedures, serum isolation, protein salting out and affinity chromatography were performed. For the antibodies characterization and application, the following methods were used: enzyme linked immunoassay (ELISA), Western blotting, FITC-protein conjugation, flow cytometry and spectrofluorometry. The obtained polyclonal rabbit anti-human plasminogen antibodies interacted with human Glu- and Lys-plasminogen, kringles 1-3 and 1-4 of plasminogen, mini-plasminogen, the heavy and light chain of plasmin. We propose the application of anti-plasminogen antibodies for the direct ELISA, Western blot analysis, and for flow cytometry and spectrofluorometric analysis of plasminogen binding with cells. The obtained anti-plasminogen antibodies are promising tools for the investigation of plasminogen/plasmin system functions, either fibrinolytic or signaling.

وصف الملف: electronic resource

العلاقة: http://biotechnology.kiev.ua/images/storage/6_2020/yatsenko_6_2020.pdfTest; https://doaj.org/toc/2410-7751Test; https://doaj.org/toc/2410-776XTest

الوصول الحر: https://doaj.org/article/fc9543fce49d4ffea838469e71411416Test