Publications by authors named "Nawrocka E"

Some species of the Gentianaceae family are a valuable source of secondary metabolites. However, the phytochemical knowledge of some of these species remains insufficient. Therefore, this work focused on the isolation of the two main secondary metabolites in the methanolic extract from a cell suspension using preparative HPLC and the determination of their structure using UHPLC-DAD-IT-MS/MS and NMR methods.

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Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful tools in analytical chemistry. An important step in the analysis of NMR data is the assignment of resonance frequencies to the corresponding atoms in the molecule being investigated. The traditional approach considers the spectrum's characteristic parameters: chemical shift values, internuclear couplings, and peak intensities.

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H NMR spectroscopy is a powerful tool for analyzing mixtures including determining the concentrations of individual components. When signals from multiple compounds overlap, this task requires computational solutions. They are typically based on peak-picking and the comparison of obtained peak lists with libraries of individual components.

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We report a detailed NMR and NMR study of as synthesised obtained in a novel dry-synthesis method. A combination of 1D and 2D single- and triple-quantum techniques was used for the assignment of all observed signals. Minor side-products and reactants were detected in the product: , , , and two yet unknown salts containing 7-membered chain anions: and .

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The aim of this study was to compare medical and social sciences students' outcomes in terms of self-perceived stress, quality of life, and personality traits. We put particular emphasis on external and internal differences in students of specific fields-medicine, nursing, psychology, and pedagogy. In a survey, 1,783 students from Medical University of Gdańsk and University of Gdańsk participated in our study, of whom 1,223 were included in the final statistical analysis.

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Article Synopsis
  • * Traditional H NMR techniques have low resonance frequency dispersion, making it challenging to identify different metabolites effectively.
  • * The article highlights a new approach to analyzing H NMR spectra that focuses on temperature-induced changes in chemical shifts, which are consistent across metabolite mixtures and can be quickly measured using the Radon transform method.
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NMR spectroscopy offers unique benefits for ligand binding studies on isotopically labelled target proteins. These benefits include atomic resolution, direct distinction of binding sites and modes, a lowest detectable affinity limit, and function independent setup. Yet, retracing protein signal assignments from apo to holo states to derive exact dissociation constants and chemical shift perturbation amplitudes (for ligand docking and structure-based optimization) requires lengthy titration series of 2D heteronuclear correlation spectra at variable ligand concentration that may exceed the protein's lifetime and available spectrometer time.

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S-adenosylmethionine (SAM) is one of the most important enzyme substrates. It is vital for the function of various proteins, including large group of methyltransferases (MTs). Intriguingly, some bacterial and eukaryotic MTs, while catalysing the same reaction, possess significantly different topologies, with the former being a knotted one.

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Nuclear magnetic resonance spectroscopy (NMR) is a versatile tool of chemical analysis allowing one to determine structures of molecules with atomic resolution. Particularly informative are two-dimensional (2D) experiments that directly identify atoms coupled by chemical bonds or a through-space interaction. Thus, NMR could potentially be powerful tool to study reactions in situ and explain their mechanisms.

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Background: Pneumatosis cystoides intestinalis (PCI) is a rare disorder characterized by the presence of multiple gas collections in the subserosal or submucosal intestinal wall of the large or small intestine. We report two cases of PCI in the course of chronic graft-versus-host disease.

Case Report: A 5-year-old girl was treated for acute lymphoblastic leukemia.

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Background: Coronary artery calcifications (CACs) represent an important risk factor of coronary artery disease in the general population. The purpose of the study was to determine the amount of CAC, including calcium mass, in renal graft recipients early after transplantation.

Material/methods: Forty-nine patients aged 43.

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Unlabelled: The authors present a case of a 4-year old boy with a quickly growing tumor of the jaw. The CT examination revealed a destructive tumor in the body of the mandible involving soft tissues. A diagnosis of eosinophilic granuloma of the mandible was confirmed by a biopsy of the tumor.

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We report the solid-phase synthesis and some pharmacological properties of 12 position three modified analogues (peptides 1-12) of the potent non-selective antagonist of the antidiuretic (V2-receptor), vasopressor (V1a-receptor) responses to arginine vasopressin (AVP) and of the uterine contracting (OT-receptor) responses to oxytocin (OT), [1(-beta mercapto-beta,beta-pentamethylenepropionic acid)-2-O-ethyl-D-tyrosine 4-valine] arginine vasopressin [d(CH2)5D-Tyr(Et)2VAVP] (A) and two analogues of (B) (peptides 13,14), the 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid3 (Tic3) analogue of (A). Peptides 1-12 have the following substituents at position three in (A): (1) Pro; (2) Oic; (3) Atc; (4) D-Atc; (6) D-Phe; (7) Ile; (8) Leu; (9) Tyr; (10) Trp; (11) Hphe; (12) [HO]Tic; Peptide (13) is the Tyr-NH2(9) analogue of (B): Peptide (14) is the D-Cys(6) analogue of (B). All 14 new peptides were evaluated for agonistic and antagonistic activities in in vivo V2 and V1a assays and in vitro (no Mg2+)n oxytocic assays.

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We report the solid-phase synthesis and antagonistic potencies of 25 analogues (1-25) of [1-(beta-mercapto-beta,beta-pentamethylenepropionic acid),2-O-ethyl-D-tyrosine,4-valine]arginine-vasopressin (d(CH2)5D-Tyr(Et)2-VAVP) (A) and of the related Ile4 (D) and [D-Phe2,Ile4] (E) analogues, potent antagonists of the antidiuretic (V2-receptor) and of the vasopressor (V1a-receptor) responses to arginine-vasopressin (AVP). Six of these peptides (1, 13, 17, 19, 21, and 23) have the Pro-Arg-Gly-NH2 tripeptide side chain fully or partially replaced or extended by ethylenediamine (Eda). The remaining 19 peptides have L- or D-amino acids retrolinked to these six C-terminal Eda peptides.

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The performed studies covered the effect of tuftsin, tetrapeptide stimulating many components of immunological reactions, to histamine concentration in lungs, kidneys, liver, duodenum as well as in the blood of rabbits and guinea-pigs. Tuftsin was given intravenously in a single injection (0.5 mg/kg), and for guinea-pigs also in one-hour infusion (1.

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The performed studies dealt with the effect of tuftsin (tetrapeptide Thr-Lys-Pro-Arg), a stimulator of many components of immunological reactions, exerted on histamine concentration in lungs, kidneys, liver, duodenal wall and arterial blood of guinea-pigs. Tuftsin was given intraperitoneally, in a single dose (0.5 and 1.

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The C-terminal SP7-11 pentapeptide (Phe-Phe-Gly-Leu-Met-NH2) was found to suppress in vitro the immune response in a dose of 1-5 micrograms/ml. It produced also a distinct immunosuppression in vivo, by both per os and intraperitoneal, applications. In contrast, the N-terminal SP1-4 fragment (Arg-Pro-Lys-Pro) suppressed the response at a dose of 0.

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The N-terminal tetrapeptide of substance P (SP1-4) was found to produce analgesia, after the icv injection to the rat brain, which is lower in its intensity than that produced by tuftsin (Thr-Lys-Pro-Arg tetrapeptide). Among investigated tuftsin analogues Thr-Lys-Pro-Thr and Thr-Lys-Pro-Thr-Asp (partial sequences of S-protein of HB virus) were weakly active, Thr-Arg-Pro-Arg was inactive, and Thr-Lys-Pro-Gly-Arg produced a weak hyperalgesia 30 min after the icv injection. The obtained results were compared with those obtained previously in the phagocytosis stimulation test.

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The syntheses of HBV S-protein partial sequences: Thr-Lys-Pro-Thr (I), Thr-Lys-Pro-Thr-Asp (II), and Thr-Lys-Pro-Thr-Asp-Gly (III) and also of pentapeptide Thr-Lys-Pro-Gly-Arg (IV), are described. For the peptides II and III inhibitory activity against tuftsin was found. Peptide IV (an analogue of tuftsin-inhibitor Thr-Lys-Pro-Pro-Arg) demonstrated a tuftsin-like activity in the phagocytosis experiments.

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The analgesic potency of the C-terminal dipeptide of tuftsin (Pro-Arg) was found to be much stronger than that of the C-terminal of bradykinin dipeptide Phe-Arg. It was also found that the tripeptide fragment of bradykinin (Pro-Phe-Arg) and its D-Pro analog (D-Pro-Phe-Arg) are deprived of analgesic activity. The attempt to synthesize kyotorphin analogs containing fluorescence label (DMAPhe-Arg and D-DMAPhe-Arg; DMAPhe: 4'-dimethylamino-phenylalanine) resulted in inactive compounds.

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A variety of structural changes were made in the C-terminals of four potent antidiuretic (V2) antagonists. The parent analogs were all derivatives of [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid)]arginine-vasopressin, d(CH2)5AVP, namely d(CH2)5[D-Phe2,Ile4]AVP, d(CH2)5[D-Ile2,Ile4]AVP, d(CH2)5[D-Tyr(Et)2, Val4]AVP and d(CH2)5[D-Tyr(Et)2,Ile4]AVP. A number of amino acid amides were substituted for the C-terminal 9-glycinamide without reducing their V2-antagonistic potencies in rats.

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We report the solid-phase synthesis of 12 desGly and 12 desGly(NH2) analogues of arginine-vasopressin (AVP), two highly selective antidiuretic (V2) agonists, four vasopressor (V1) antagonists, and five V2/V1 antagonists. The parent AVP agonists are (1) AVP, (2) 1-deamino[8-D-arginine]vasopressin (dDAVP), and (3) its 4-valine analogue, dVDAVP. The parent V1 antagonists are (4) [1-(beta-mercapto-beta,beta-pentamethylenepropionic acid)] arginine-vasopressin (d(CH2)5AVP), (5) d(CH2)5VDAVP, (6) [1-deaminopenicillamine,4-valine,8-D-arginine]vasopressin (dPVDAVP), and (7) d(CH2)5[Tyr(Me)]AVP.

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Using an indirect immunofluorescent test with Hantaan 76-118 and Puumala strains as antigens, antibodies against haemorrhagic fever with renal syndrome viruses were found for the first time in human in Laos and Viet-Nam and confirmed the previously published results in Thailand. These results suggest the existence of an Hantaan-related virus in these countries.

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