Wyniki wyszukiwania - Biblioteka Nauki

1

APPLICATION OF ION PAIR RP–HPLC METHOD IN PHARMACEUTICAL QUALITY CONTROL DISSOLUTION TESTING FOR SIMULTANEOUS ESTIMATION OF COMBINED TABLET DOSAGE FORMS WITH ACETYLSALICYLIC ACID AND GLYCINE

100%

Kowalska M. K. , Wozniak M. , Kijek M. , Krawczyk M. , Janas S.

Acta Poloniae Pharmaceutica - Drug Research

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2018

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tom 75

|

nr 3

EN

The aim of the paper was to present the possibility of applying the novel method (RP-HPLC ion pair method) for the simultaneous dissolution determination of combined tablet dosage form containing acetylsalicylic acid and glycine in pharmaceutical industry. The samples were gradient eluted using a Pursuit XS Ultra C18 column (150x3.0 mm, with a particle size of 2.8µm) with variable composition of mobile phase A (1-heptanesulfonic acid sodium salt aqueous solution (2.8 g/L), pH 2.2 ± 0.05 adjusted with orthophosphoric acid) and phase B (methanol). The detection was carried out at 210 nm with a consist flow rate of 0.4 mL min−1. The method was validated by determining precision (repeatability and intermediate precision), accuracy, specificity, linearity, range, system suitability, robustness and stability in accordance with ICH guidelines. The method was accurate, precise and linear within the range of 0.03 – 0.18 mg mL−1 for acetylsalicylic acid and 0.016 – 0.096 mg mL−1 for glycine. The method is simple, convenient and suitable for analyzing acetylsalicylic acid and glycine in pharmaceutical formulations. The method could also be used for routine assay determination after small modification of sample preparation.

2

Chalcopyrite leaching by amino acid solutions in the presence of hydrogen peroxide

100%

Nurtazina N. , Uvarov N. , Azhigulova R. , Tyapkin P.

Physicochemical Problems of Mineral Processing

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2022

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tom Vol. 58, iss. 6

art. no. 157067

EN

It is demonstrated that amino acids such as glycine, betaine, and lysine may be applied as selective copper leaching agents in the process of hydrochemical oxidation of chalcopyrite at atmospheric pressure and in the temperature range 25÷65 °C. The advantage of the proposed method is its relative environmental friendliness. Solid samples of the initial mineral and leached chalcopyrite residues were analyzed by X-ray diffraction analysis, and Mössbauer and Raman spectroscopy. The results of the atomic absorption analysis showed that copper's extraction efficiency increased when the experiment's duration was raised and when the process temperature was higher. The leaching ability of amino acids was evaluated by the specific leaching rate of chalcopyrite in these reagents. Amino acid leaching was thought to be mainly due to the complexation of copper (II) glycinates, copper (II) betainates and copper (II) lysinates. This reaction can be enhanced by adding hydrogen peroxide to the system as an oxidant. It was determined that glycine was more effective as a leaching agent than betaine and lysine. Based on experimental data, it was assumed that the most possible mechanism is selective copper leaching due to the formation of chalcopyrite-based solid solution Cu1-XFeS2.

3

Experimental and computational investigation with Hirshfeld surface analysis of bis(glycine) strontium dichloride trihydrate

100%

Radhakrishnan A. , Muppudathi A. L. , Jeyaperumal K. S.

Materials Science Poland

|

2020

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tom Vol. 38, No. 4

545--552

EN

Good-quality semiorganic single crystals of bis(glycine) strontium dichloride trihydrate (GSC) were grown by slow evaporation technique. The lattice parameters of the grown crystal were verified through single crystal X-ray diffraction. Besides, the crystallinity of the material was analyzed with powder X-ray diffraction. The fingerprint of functional groups of this material was analyzed by FT-IR technique. The UV transparency cutoff wavelength of GSC was found to be 240 nm and the crystal exhibited 80 % transmission in the entire visible region. All intermolecular and intramolecular interactions of the grown crystal were interpreted by Hirshfeld surface analysis, and the strength of the interactions was graphically illustrated by fingerprint graphs. The intramolecular charge transfers of the crystal were assessed through frontier molecular orbital analysis.

4

Differences in the structures of the elongation factors (EF-2) isolated from guerin epithelioma and rat liver

86%

Sredzinska K. , Gajko A. , Galasinski W.

Bulletin of the Polish Academy of Sciences. Biological Sciences

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1991

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tom 39

|

nr 2

5

Synthesis and Characterization of Two Novel Inorganic-Organic Hybrid Materials Based on Polyoxotungstoborate: [L-C2H5NO2-H]3[H2BW12O40]ź5H2O and [CH4N2O-H]2[H3BW12O40]ź5H2O (C2H5NO2 = Glycine; CH4N2O = Urea)

86%

Alizadeh M. H. , Eshtiagh-Hosseini H. , Mirzaei M. , Hosseini-Nejad M.

Polish Journal of Chemistry

|

2009

|

tom Vol. 83, nr 9

1583-1589

EN

Two novel hy drated in or ganic-or ganic hy brids, namely [L-C2H5NO2-H]3[H2BW12O40]ź ź5H2O (1) and [CH4N2O-H]2[H3BW12O40]ź5H2O (2), where C2H5NO2 and CH4N2O are glycine and urea, respectively, have been synthesized and characterized by CHN microanalysis, IR, UV, and 1H NMR spectroscopies. According to the obtained results, molecular structure of 1 consists of tungstoborate anions linked to glycinium cations via van der Waals interactions and hydrogen bonding. Three [L-C2H5NO2-H]+ moieties encompass each [H2BW12O40]3- and, almost certainly, the same is true for 2. The O atoms of polyoxometalates and water, as well as the N atoms of L-glycine and urea are in volved in hydrogen bonding. Characteristic UV bands of the Keggin anion, alfa-H5[BW12O40]ź ź19H2O, are observed at 257 nm, as would be expected.

6

Evaluation of solid dispersions containing magnesium levulinate salts with selected carriers

86%

Marcoin W. , Szulc-Musiol B.

Journal of Elementology

|

2011

|

tom 16

|

nr 4

EN

Among the methods applied to ensure optimal pharmaceutical availability of a drug is the incorporation of solid dispersions, i.e. combinations containing a therapeutic substance and a carrier deprived of its pharmacological activity. While manufacturing solid dispersions, special attention must be paid to carriers with a polymeric structure and hydrophilic properties, e.g. polyvinylpyrrolidone (PVP) and also phosphatidylcholine (PC). The aim of this study has been to evaluate the influence of the carriers PVP and PC 45 on pharmacokinetic parameters of Mg2+ absorption from Mg(Lev)2, Mg(LevGly), Mg(LevArg) as well as from solid dispersions containing these salts. The o/w partition coefficient was determined and the log P value calculated for pure salts and for solid dispersions containing the salts during this study. The process of Mg2+ absorption was examined in vitro on a model of the rat’s small intestine. Our analysis of the results indicates that addition of PVP or PC 45 to solid dispersions (containing magnesium levulinate salts) significantly improves the degree of Mg2+ ion absorption. It has been found that addition of PVP and PC 45 to solid dispersions with magnesium levulinate salts significantly influences the rate of Mg2+ absorption from the formulations. Moreover, the results indicate that additional ligand (glycine or arginine) in the structure of magnesium levulinate triggers the effect consisting in depressed lipophilicity for these compounds. Using the PVP or PC 45 carriers for making solid dispersions containing magnesium levulinate and derivatives with glycine or arginine ligands is quite a promising solution for attaining improved pharmaceutical availability of drugs.

PL

Jedną z metod osiągnięcia optymalnej dostępności farmaceutycznej leku jest zastosowanie stałych rozproszeń, układów zawierających substancję leczniczą i nośnik, który jest pozbawiony własnego działania farmakologicznego. Przy wytwarzaniu stałych rozproszeń na szczególną uwagę zasługują nośniki o budowie polimerowej i właściwościach hydrofilowych. Należą do nich m.in. poliwinylopirolidon (PVP), a także fosfatydylocholina. Celem badań była ocena wpływu wybranych nośników: poliwinylopirolidonu (PVP) i roztworu fosfatydylocholiny (PC 45) na poprawę parametrów farmakokinetycznych procesu wchłaniania jonów Mg2+ z soli lewulinianu magnezowego Mg(Lev)2, Mg(LevGly), Mg(LevArg) oraz ze stałych rozproszeń zawierających te sole. W badaniach wyznaczono współczynnik podziału o/w i wyliczono wartość log P dla czystych soli oraz dla stałych rozproszeń zawierających te sole. Badania procesu wchłaniania jonów Mg2+ przeprowadzono metodą in vitro na modelu jelita cienkiego szczura. Wykazano, że dodatek PVP lub PC 45 do stałych rozproszeń zawierających sole lewulinianu magnezowego znacząco wpływa na poprawę stopnia wchłaniania. Na podstawie tych badań stwierdzono, że dodatek PVP lub PC 45 do stałych rozproszeń z solami lewulinianu magnezowego istotnie (p=0.01) wpływa na szybkość procesu wchłaniania jonów Mg2+ z otrzymanych formulacji. Ponadto wyniki badań wskazują, że dodatkowy ligand (glicyna, arginina) w strukturze cząsteczki lewulinianu magnezowego wywołuje efekt zmniejszenia lipofilowości dla tych związków. Zastosowanie nośników PVP lub PC 45 do wytwarzania stałych rozproszeń zawierających lewulinian magnezowy i pochodne z ligandami glicyny lub argininy jest obiecujące w poprawie dostępności farmaceutycznej.

7

Effect of fuel type on the combustion reaction behavior, phase structure and morphology of Ni0.5Co0.5Fe2O4 nanoparticles

86%

Sedghi A. , Salehkooh E. A. , Chadorbafzade M.

Materials Science Poland

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2020

|

tom Vol. 38, No. 2

341--349

EN

Nickel-cobalt ferrite spinels are ferrimagnetic ceramic materials that possess a great potential for application in high-density magnetic media, recording, color imaging, ferrofluids, and high-frequency devices. A change of their structure from micro- to nano- improves their properties drastically, therefore many methods have been investigated to fabricate nanopowder of these spinels. Gel combustion method is one of them. In this research, Ni0.5Co0.5Fe2O4nanoparticles were fabricated via gel combustion method using metallic nitrates as an oxidant and citric acid, glycine and urea as fuels and the effects of fuel type on the reaction behavior, structure and morphology of Ni0.5Co0.5Fe2O4nanoparticles were investigated. The reaction behavior was studied by thermal analysis method (TGA-DTA), crystallite size of powders was characterized by X-ray diffraction (XRD) and their morphology was studied by FE-SEM. The results revealed that the reaction was initiated in urea, glycine and citric at 219 °C, 197 °C, 212 °C, respectively. Samples fabricated from glycine and citric acid had a pure spinel structure but the others fabricated with urea fuel had iron oxide impurity. The crystallite size of nickel cobalt ferrite nanoparticles was in the range of 58 nm to 64 nm and the nanoparticles were agglomerated.

8

Influence of glycine and arginine ligands on some of physicochemical properties of magnesium aspartate

86%

Marcoin W. , Duda H.

Journal of Elementology

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2006

|

tom 11

|

nr 1

EN

Hydrate complexes of magnesium aspartate, magnesium aspartate glycinate, magnesium aspartate arginate have been synthesized and characterized by the elemental and spectral analysis. The formulae of the magnesium complexes were Mg(C4H6O4N) • 4H2O, Mg(C6H10O5N2) • 5H2O, and Mg(C10H19O5N5) • 7H2O. The main thermal process: dehydration of the complexes, was studied using the thermoanalytical methods: differential thermal analysis (DTA), thermogravimetric analysis (TG), and differential scanning calorimemtry (DSC) measurements. The influence of additional ligands (glycinate or arginate) introduced to the structure of magnesium aspartate on the physicochemical properties of the newly synthesized compounds was analysed.

PL

Metodą analizy elementarnej i spektralnej scharakteryzowano syntezowane hydraty kompleksów asparaginianu magnezowego, glicynianoasparaginianu magnezowego, arginiano-asparaginianu magnezowego, Kompleksy magnezowe o wzorach : Mg(C4H6O4N) • 4H2O, Mg(C6H10O5N2) • 5H2O, and Mg(C10H19O5N5) • 7H2O. Zastosowano metody termoanalityczne: różnicową termiczną analizę (DTA), termograwimetryczną analizę (TG), skaningową kalorymetrię różnicową (DSC) do badania głównego procesu termicznego: dehydratacji badanych kompleksów. Potwierdzono wpływ wprowadzonych do struktury asparaginianu magnezowego dodatkowych ligandów glicyny lub argininy na fizykochemiczne właściwości nowo syntezowanych związków.

9

Estimation of absorption of magnesium nicotinate and its derivatives with selected amino acids

72%

Marcoin W. , Szulc-Musiol B.

Journal of Elementology

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2009

|

tom 14

|

nr 2

313-321

EN

Preparation of solid dispersions is a popular pharmaceutical technology designed to improve the solubility and absorption characteristics of drugs. Solubilizing and moisturizing of carriers show influence on therapeutic substances; although dissolution of molecular dispersion of particles of the therapeutic substance in a neutral carrier is of utmost importance. This paper present the results of the research on influence of modification the structure of magnesium nicotinate Mg(Nic) with ligands, glycine and arginine, on the absorption process of Mg2+ions in vitro. The absorption area was the small intestine of a rat. It was found that structural changes with an additional arginine or glycine ligand affect the absorption process of Mg2+ions. Moreover, the effect of hydrophilic carriers on the partition coefficient (log P) for the system of n-octanol and phosphate buffer was investigated for the solid dispersions containing the examined magnesium salts. Phosphatidylcholine (PC-45) and polyvinylpirrolidone (PVP K-30) were used as carriers for solid dispersions with of magnesium salts. It was confirmed that using auxiliary substances PC-45 and PVP changes significantly (p<0.05) P values, corresponding to increasing hydrophobic properties of solid dispersions of the examined salts. It was found that modification of the structure of magnesium nicotinate by amino acids such as arginine or glycine positively influences the absorption process Mg2+ ions. The research carried out on properties of the solid dispersions containing magnesium salts and phospatidylcholine (PC-45) or magnesium salts and polyvinylpirrolidone (PVP K30) showed positive influence of these auxiliary substances.

PL

Wytwarzanie stałych dyspersji jest popularną metodą technologiczną stosowaną w celu poprawy rozpuszczalności i wchłaniania leków. Właściwości solubilizujące oraz zwilżające nośników mają wpływ na proces rozpuszczania substancji leczniczych. W pracy przedstawiono badania wpływu modyfikacji struktury nikotynianu magnezowego Mg(Nik) aminokwasami (argininą lub glicyną) na proces wchłaniania jonów Mg2+in vitro. Powierzchnię absorpcji stanowiło jelito cienkie szczura. Stwierdzono, że dodatkowy ligand argininy lub glicyny w strukturze nikotynanu magnezu wpływa na zmianę parametrów procesu wchłaniania jonów Mg2+. Ponadto badano wpływ nośników hydrofilowych na współczynnik podziału o/w układu n-oktanol/bufor fosforanowy wybranych soli magnezowych stałych rozproszeń. Do sporządzenia stałych rozproszeń z badanymi solami magnezowymi zastosowano fosfatydylocholinę 45% (PC-45) i polivinylopirolidon (PVP K-30). Stwierdzono, że zastosowanie substancji pomocniczych PC-45, PVP znacząco (p<0.05) wpływa na zmianę wartości log P, a zatem wzrasta hydrofobowość stałych rozproszeń badanych soli. Wykazano, że modyfikacja struktury nikotynianu magnezu argininą lub glicyną wpływa na poprawę absorpcji jonów magnezowych. Badania właściwości stałych rozproszeń zawierających sole magnezowe – fosfatydylocholinę (PC-45) lub sole magnezowe – poliwinylopirolidon (PVP K-30) wykazały pozytywny wpływ zastosowanych substancji pomocniczych.

10

Zmiana nasilenia objawów pozytywnych, negatywnych oraz psychopatologii ogólnej (PANSS) u chorych na schizofrenię po 6 tygodniach augmentacji terapii lekami przeciwpsychotycznymi – glicyną lub donepezilem

72%

Rabe-Jabłońska J. , Strzelecki D.

Psychiatria i Psychologia Kliniczna

|

2005

|

tom 5

|

nr 4

178-189

EN

In aetiopathogenesis of schizophrenia the key role is played by dopaminergic, but also serotoninergic, glutamatergic systems as well as cholinergic neurons. Donepezil is a mixed inhibitor of acetylcholinesterase, selectively inhibiting acetylcholinesterase. A review of the studies, in which donepezil was used for augmentation of antipsychotic treatment does not provide explicit information on the effects of such procedures within a change of scores on PANSS. Pursuant to the assumptions of hypoglutamatergic hypothesis of schizophrenia, the transmission was stimulated within this system. To its stimulation through NMDA receptor among others glycine was used, i.e. prevalent amino acid of the simplest structure, the basic transmitter of glycinergic neurons counted among class I – neurotransmitters, additionally functioning as a coagonist and modulator, also within the glutamatergic system. In 2005 a meta-analysis of studies appeared, from which it results that glycine and D-serine significantly decrease the severity of negative symptoms. The study was aimed at establishing whether or not adjunctive glycine or donepezil applied for 6 weeks with antipsychotic treatment statistically significantly affect a change in the severity of positive symptoms, negative symptoms, general psychopathology in patients at a stable period of the disease. Subjected to the study was a group of 62 patients aged 18-55 years, suffering from paranoidal schizophrenia (DSM-IV) at the mental condition stabilised for at least half a year, without a change in the type and dose of antipsychotic drug at that time. The following methods were used: 1) confirmation of stabilisation of the mental condition and stable pharmacotherapy for the required period according to analysis of medical documentation, interview and evaluation of the current status; 2) augmentation of the hitherto applied antipsychotic treatment by adding donepezil or glycine and 3) evaluation of the severity of negative symptoms, positive symptoms and general psychopathology (PANSS) before and after 6 week augmentation by donepezil or glycine and occurrence of adverse symptoms. Results: Statistically significant differences were obtained after 6 weeks in a group treated with antipsychotic drugs and glycine (primarily within negative symptoms and general psychopathology, less within positive symptoms), whereas in the group additionally treated with donepezil no such differences were found.

PL

W etiopatogenezie schizofrenii kluczową rolę odgrywa układ dopaminergiczny, ale swój udział mają także układ serotoninergiczny i glutaminianergiczny oraz neurony cholinergiczne. Donepezil jest mieszanym inhibitorem acetylocholinesterazy selektywnie hamującym raczej acetylocholinesterazę. Przegląd badań, w których do augmentacji leczenia przeciwpsychotycznego stosowano donepezil, nie dostarcza jasnych informacji na temat efektów takiego postępowania w zakresie zmiany punktacji w podskalach PANSS. Zgodnie z założeniami hipoglutaminianergicznej hipotezy schizofrenii stymulowano transmisję w obrębie tego układu. Do jego pobudzenia poprzez receptor NMDA stosowano m.in. glicynę – aminokwas o najprostszej budowie i szerokim rozpowszechnieniu, podstawowy przekaźnik neuronów glicynergicznych, zaliczany do klasy I neurotransmiterów, pełniący ponadto funkcję koagonisty i modulatora, m.in. w obrębie układu glutaminianergicznego. W 2005 r. ukazała się metaanaliza badań, z której wynika, że glicyna i D-seryna istotnie zmniejszają nasilenie objawów negatywnych. Celem badania było ustalenie, czy dołączenie przez okres 6 tygodni glicyny lub donepezilu do dotychczasowego leczenia przeciwpsychotycznego w sposób istotny statystycznie wpływa na zmianę nasilenia objawów pozytywnych, negatywnych, ogólnej psychopatologii u pacjentów w stabilnym okresie choroby. Badaniu poddano grupę 62 osób w wieku 18-55 lat, chorych na schizofrenię paranoidalną (DSM-IV), w stanie psychicznym ustabilizowanym od co najmniej pół roku, bez zmiany w tym czasie rodzaju i dawki leku przeciwpsychotycznego. Zastosowano następujące metody: 1) potwierdzenie stabilizacji stanu psychicznego oraz stałej farmakoterapii przez wymagany okres na podstawie analizy dokumentacji medycznej, wywiadu i oceny aktualnego stanu; 2) augmentacja dotychczasowego leczenia przeciwpsychotycznego przez dodanie donepezilu lub glicyny oraz 3) ocena nasilenia objawów negatywnych, pozytywnych i psychopatologii ogólnej (PANSS) przed i po 6 tygodniach augmentacji donepezilem lub glicyną i występowania objawów niepożądanych. Wyniki: Istotne statystycznie różnice uzyskano po 6 tygodniach w grupie leczonych lekami przeciwpsychotycznymi oraz glicyną (przede wszystkim w zakresie objawów negatywnych i psychopatologii ogólnej, mniejsze w zakresie objawów pozytywnych), natomiast w grupie leczonej dodatkowo donepezilem nie stwierdzono takich różnic.

11

Dielectric, etching and Z-scan studies of glycine doped potassium thiourea chloride crystal

72%

Azhar S. M. , Anis M. , Hussaini S. S. , Kalainathan S. , Shirsat M. D. , Rabbani G.

Materials Science Poland

|

2016

|

tom Vol. 34, No. 4

800--805

EN

Glycine doped potassium thiourea chloride (PTC) crystal has been grown by slow solution evaporation technique. The dielectric studies have been employed to examine substantial improvement in dielectric constant and dielectric loss of glycine doped PTC crystal. The etching studies have been performed to investigate the surface quality of this crystal. The z-scan studies have been carried out at 632.8 nm to explore the third order nonlinear optical nature. The negative nonlinear refraction of glycine doped PTC crystal was found to be of 7.27 × 10-12cm2/W. The origin of high magnitude of third order nonlinear optical susceptibility and reverse saturable nonlinear absorption have been investigated. The obtained results were explored to discuss the nonlinear optical applications of PTC crystal.

12

Stability of Mn(II) Complexes with Acetic Acid Derivatives

72%

Pedras M. , John E.

Polish Journal of Chemistry

|

2007

|

tom Vol. 81, nr 10

1701-1706

EN

Composition and stability constants of Mn(II) complexes with acetic, glycolic (hydroxyacetic), methoxyacetic and phenylacetic acids, glycine (aminoacetic acid), and sarcosine (N-methylglycine) were determined, at a constant ionic strength = 0.1 KNO3 using the potentiometric method at 20 graduate C. Values of stability constants were found by Bjerrum graphical method and also numerically using Martell and Motekaitis program. The following logK1,graph. values of Mn(II) complexes were found: 2.21 for the complex with acetic acid, 2.45with glycolic acid, 2.10 with methoxyacetic acid, 2.48 with phenylacetic acid, 3.10 with glycine and 3.05 with sarcosine.

13

Nucleotide sequence of nuclear tRNAGly genes and tRNAGly pseudogenes from yellow lupin [Lupinus luteus]: Expression of the tRNAGly genes in vitro and in vivo

72%

Nuc P. , Nuc K. , Szweykowska-Kulinska Z. , Pawelkiewicz J.

Acta Biochimica Polonica

|

1997

|

tom 44

|

nr 2

EN

A nuclear DNA fragment (7.8 kb) from yellow lupin (L. luteus) was sequenced and shown to contain tRNA(Gly) (GGC) genes and tRNAGly (GGC) pseudogenes organized in three tandemly repeated units: of 2565 bp and 2564 bp, and one, truncated from its 3' end, of 1212 bp. Each unit contains an identical pair of a tRNA(Gly) gene and a pseudogene, both having the same polarity. The nucleotide sequence of the gene appears colinear to L. luteus cytoplasmic tRNA(Gly) (GGC) primary structure. All three genes are efficiently transcribed in HeLa-cell nuclear extract giving two primary transcripts. The main, longer primary transcripts have each an extremely long 3' trailer of about 100 nucleotides, the structure of which is specific only for tRNAGly genes and pseudogenes (80% homology) of the studied tandem (but not for other tRNA(Gly) genes of the yellow lupin genome) as it has been shown by Southern hybridization. This distinctive feature allowed to isolate putative tRNAGly precursor(s) encoded by at least one of the three tRNA(Gly) (GGC) genes from L. luteus seedlings.

14

A partial agonist at strychnine-insensitive glycine sites facilitates spatial learning in aged rats

72%

Popik P. , Rygielska Z.

Journal of Physiology and Pharmacology

|

1999

|

tom 50

|

nr 1

15

Synthesis and immunosuppressive activity of glycine containing linear analogs of cyclolinopeptide A

72%

Siemion I. Z. , Cebrat M. , Pedyczak A. , Zimecki M. , Wieczorek Z.

Archivum Immunologiae et Therapiae Experimentalis

|

1993

|

tom 41

|

nr 5-6

16

Modulation of calcium uptake by exogenous amino acids, in Phaseolus vulgaris seedlings

72%

Rana U. , Rai V. K.

Acta Physiologiae Plantarum

|

1996

|

tom 18

|

nr 2

17

The valproic acid-induced effects on kynurenine pathway correlate with the changes in the central and peripheral concentration of amino acids

58%

Maciejak P. , Szyndler J. , Turzynska D. , Sobolewska A. , Kolosowska K. , Lehner M. , Wislowska-Stanek A. , Skorzewska A. , Hamed A. , Plaznik A.

Acta Neurobiologiae Experimentalis

|

2013

|

tom 73

|

nr 1

EN

Despite its widespread use, the mechanisms of valproic acid (VPA) action are not fully understood. In the current study, we have examined the peripheral and central effects of VPA administration on the metabolic pathway of tryptophan (TRP): concentration of its centrally active metabolites, kynurenine (KYN) and kynurenic acid (KYNA). Moreover, the role of a displacement of TRP from serum albumin binding sites, and changes in the peripheral and central concentration of amino acid including glutamate (GLU), GABA, alanine (ALA), glutamine (GLTM), glycine (GLY), aspartate (ASP), were also studied. We found that VPA administration produced a progressive and strong increase in the central concentration of KYNA, KYN and TRP. Simultaneously, TRP concentration in plasma declined while the peripheral increase of KYNA in plasma was weaker and occurred earlier than in the hippocampus. We also observed that administration of ibuprofen to rats, a prototypic drug used to study drug binding to serum albumin, strongly increased the amount of a free serum and hippocampal TRP concentration, to a degree similar to the effect of VPA. Moreover, we found that the most pronounced changes in the concentration of amino acids caused by administration of VPA include an increase of GLU and a decrease of ALA in the plasma as well as a decrease of ASP and an increase of GABA in the brain. The factor analysis revealed that the changes in the concentrations of TRP, determined both in the plasma and in the hippocampus grouped strongly with the changes in the plasma concentrations of GLU and the central concentration of ASP. Our results showed that administration of VPA strongly modifies the activity of the kynurenine pathway with significant changes in TRP, KYN and KYNA levels in the CNS. The reason for this may be a strong VPA-induced displacement of TRP from its binding sites to plasma albumin. It appears also that the changes in TRP evoked by VPA administration due to competition for transport into the brain, may result in a shift in the central and peripheral balance between branched-chain (BCAA) and aromatic amino acids (AAA). This may lead to a decrease in BCAA transport to the brain, leading to a deficit of BCAAs as a donor of amino groups to the process of GLU resynthesis from pyruvate. Changes in the BCAA/ AAA ratio, arising as a consequence of changes in the TRP level, could explain an observed increase in the plasma concentrations of GLU and a decrease in the ASP concentrations in the brain that occurred after administration of VPA. In sum, given the neuroprotective role of KYNA, the current study suggests that stimulation of the kynurenine pathway may also apply to the central and peripheral concentration of amino acids. The modification of the activity of the kynurenine pathway may at least in part contribute to the related antiepileptic and neuroprotective mechanisms of VPA action.

18

Wpływ osnowy polimerowej na piezooptykę nanokrystalitów γ-glicyny

58%

Oźga K. , Nabiałek M. , Szota M. , Rakus P. , Czaja P. , Dośpiał M. , Berdowski J. , Tylczynski Z.

Przetwórstwo Tworzyw

|

2011

|

tom [R.] 17, nr 6

483-487

PL

Ustalono główną rolę polarności osnów polimerowych na dyspersję zjawiska piezooptyki nanokrystalitów γ-glicyny wprowadzonych w osnowy polimerowe poli(metakrylanu metylu) (PMMA) oraz poliwęglanu (PC). Stwierdzono pojawienie się efektu piezooptycznego pod wpływem obróbki laserowej dwoma wiązkami świetlnymi o długości fali 1064 nm oraz 532 nm, generowanymi z jednego źródła laserowego YAG: Nd. Optymalne rozmiary nanokrystalitów γ-glicyny, dla których otrzymano odpowiednie wartości współczynników piezooptyczych wynosiły 50-80 nm (optymalna koncentracja 5,5 % w j. wag.). W pracy badano relaksacje oraz zależności spektralne odpowiednich współczynników tensora piezooptycznego.

EN

We have established a principal role of the polarity of polymer matrices on the piezooptical dispersion of the γ-glycine nanocrystallites embedded into the polymethymethacrylate (PMMA) and polycarbonate (PC) matrices. We have found that the optical treatment by bicolor two laser beams at 1064 nm and 532 nm which are originating from the same 10 ns Nd:YAG lasers, causing occurrence of the piezooptical effects. The optimal content of the γ-glycine nanocrystallites with respect to the magnitude of piezooptical coefficients with the sizes within the range 50-80 nm correspondence to the 5.5 % in weighting unit. We studied relaxation and spectral dependences of the corresponding coefficients of piezooptic tensor.

19

Zmiana parametrów elektrookulograficznych u chorych na schizofrenię leczonych glicyną. Wyniki prospektywnego badania otwartego

58%

Strzelecki D. , Rabe-Jabłońska J.

Psychiatria i Psychologia Kliniczna

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2009

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tom 9

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nr 4

223-232

EN

Glycine is a noncompetitive co-agonist of NMDA receptor, ionotropic receptor of glutamatergic brain system. Numerous studies indicated its advantageous effects on the primary negative symptoms of schizophrenia. The main research hypothesis assumes a correlation between negative symptoms of schizophrenia and eye movement abnormalities. The article is aimed at evaluation of a change within eye movements in result of glycine at a dose of 0.8 g/kg bm/day per os added to the hitherto applied treatment with antipsychotics. Material and methods: Twenty eight patients with schizophrenia with predominant negative symptoms completed a 6-week prospective open-label study, during which they were given glycine per os (no more than 60 g/24 h). At the beginning and at the end of the study the patients had their eye movements tested (eye pursuit tracking, saccadic and antisaccadic tasks) and the changes of schizophrenia symptoms was evaluated using PANSS. Results: After 6-weeks’ use of glycine, a significant decrease in the number of errors in antisaccadic task was observed (p<0.05). Moreover there is a correlation between an improvement of results in antisaccadic task (fewer errors) and amelioration of negative symptomatology in the examined group after use of glycine (p<0.05). A significant improvement of the gain at the object’s speed of 29°/s was also observed. Conclusions: Glycine in the applied dose may advantageously affect the eye movements, clearly disturbed in schizophrenia, which seems to confirm on the one hand the correlation of negative symptoms with oculomotor pathology, on the other hand – advantageous effects of glycine on negative symptoms expressed by a lower number of errors in antisaccadic task.

PL

Glicyna jest niekompetycyjnym koagonistą receptora NMDA, jonotropowego receptora układu glutaminianergicznego. W licznych badaniach wykazano jej korzystny wpływ na pierwotne objawy negatywne schizofrenii. Główna hipoteza badawcza zakłada związek między objawami negatywnymi schizofrenii a zaburzeniami ruchów gałek ocznych. Celem pracy była ocena zmiany w zakresie ruchów gałek ocznych wskutek dołączenia glicyny w dawce 0,8 g/kg m.c./dobę per os do dotychczasowego leczenia lekami przeciwpsychotycznymi. Materiał i metody: Dwudziestu ośmiu chorych na schizofrenię z dominującymi objawami negatywnymi ukończyło 6-tygodniowe prospektywne badanie typu otwartego, podczas którego podawano im doustnie glicynę (maksymalnie 60 g/dobę). Na początku i końcu badania wykonano pacjentom badania ruchów gałek ocznych (testy śledzenia, sakadowy i antysakadowy) oraz dokonano oceny nasilenia objawów schizofrenii przy pomocy PANSS. Wyniki: Po 6-tygodniowym okresie stosowania glicyny obserwowano istotne zmniejszenie liczby popełnianych błędów w teście antysakadowym (p<0,05). Ponadto odnotowano istnienie korelacji między poprawą wyników w teście antysakadowym a nasileniem objawów negatywnych w badanej grupie (p<0,05). Zaobserwowano istotną poprawę współczynnika nadążania przy prędkości obiektu 29°/s. Wnioski: Glicyna w zastosowanej dawce może korzystnie wpływać na ruchy gałek ocznych wyraźnie zaburzone w schizofrenii, co zdaje się potwierdzać z jednej strony powiązanie objawów negatywnych z patologią okoruchową, z drugiej zaś korzystne działanie glicyny na objawy negatywne wyrażone poprzez mniejszą liczbę błędów w teście antysakadowym.

20

Inhibition of glutamate: glyoxylate and serine: glyoxylate aminotransferases from rye seedlings [Secale cereale L.] by glyoxylate or glyoxylate in the presence of ammonium ion

58%

Paszkowski A.

Acta Physiologiae Plantarum

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1994

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tom 16

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nr 3