Recently, it was described that neutral glycans can be distinguished from those containing sialic acid at the mercury electrode after modification with osmium(VI) N,N,N',N'-tetramethylethylenediamine (Os(VI)tem). Our work shows the possibility of studying glycans and glycoproteins at pyrolytic graphite electrodes depending on thepresence of sialic acid. Short glycans, glycans released from glycoproteins, and glycoproteins themselves yielded similar voltammetric responses after their modification by Os(VI)tem. Os(VI)tem modified glycans and glycoproteins produced acouple of cathodic and anodic peaks. Changing peak heights and potentials of glycans and glycoproteins pointed out the presence of sialic acid. These findings could be utilized to improve glycoprotein sensing by chemical modification.

• Klíčová slova
• Chemical modification of carbohydrates, Electrochemical analysis, N-acetyl neuraminic acid, Osmium(VI) complexes, Sialoglycoproteins,
• MeSH
• elektrochemické techniky * metody   MeSH
• elektrody MeSH
• glykoproteiny * chemie   analýza   MeSH
• grafit * chemie   MeSH
• kyselina N-acetylneuraminová * chemie   analýza   MeSH
• polysacharidy * chemie   analýza   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glykoproteiny * MeSH
• grafit * MeSH
• kyselina N-acetylneuraminová * MeSH
• polysacharidy * MeSH

Sialic acids are negatively charged carbohydrates that are components of saccharide chains covalently linked to macromolecules. Sialylated glycoproteins are important for most biological processes, including reproduction, where they are associated with spermatogenesis, sperm motility, immune responses, and fertilization. Changes in the glycoprotein profile or sialylation in glycoproteins are likely to affect the quality of ejaculate. The aim of this study was to determine differences in the degree of sialylation between normozoospermic ejaculates and ejaculates with a pathological spermiogram using two lectins, Sambucus nigra (SNA) and Maackia amurensis (MAL II/MAA) recognizing α-2,6 or α-2,3 linkage of Sia to galactosyl residues. Our results show a close relationship between seminal plasma (SP) sialoproteins and the presence of anti-sperm antibodies in the ejaculate, apoptotic spermatozoa, and ejaculate quality. Using mass spectrometry, we identified SP sialoproteins such as, semenogelins, glycodelin, prolactin-inducible protein, lactotransferrin, and clusterin that are associated with spermatozoa and contribute to the modulation of the immune response and sperm apoptosis. Our findings suggest a correlation between the degree of SP glycoprotein sialylation and the existence of possible pathological states of spermatozoa and reproductive organs. Glycoproteins sialylation represents a potential parameter reflecting the overall quality of ejaculate and could potentially be utilised in diagnostics.

• Klíčová slova
• Anti-sperm antibodies, Apoptosis, Ejaculate quality, Glycoprotein, Human,
• MeSH
• analýza spermatu metody   MeSH
• apoptóza MeSH
• ejakulace MeSH
• glykodelin metabolismus   MeSH
• glykoproteiny metabolismus   MeSH
• klusterin metabolismus   MeSH
• kyseliny sialové metabolismus   MeSH
• laktoferrin metabolismus   MeSH
• lektiny metabolismus   chemie   MeSH
• lidé MeSH
• motilita spermií MeSH
• proteiny semenné plazmy metabolismus   MeSH
• sekreční proteiny semenných váčků metabolismus   MeSH
• sperma * metabolismus   chemie   MeSH
• spermie * metabolismus   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• glykodelin MeSH
• glykoproteiny MeSH
• klusterin MeSH
• kyseliny sialové MeSH
• laktoferrin MeSH
• lektiny MeSH
• PAEP protein, human MeSH Prohlížeč
• proteiny semenné plazmy MeSH
• sekreční proteiny semenných váčků MeSH
• seminal vesicle-specific antigen MeSH Prohlížeč

In the shadow of SARS-CoV-2, influenza seems to be an innocent virus, although new zoonotic influenza viruses evolved by mutations may lead to severe pandemics. According to WHO, there is an urgent need for better antiviral drugs. Blocking viral hemagglutinin with multivalent N-acetylneuraminic acid derivatives is a promising approach to prevent influenza infection. Moreover, dual inhibition of both hemagglutinin and neuraminidase may result in a more powerful effect. Since both viral glycoproteins can bind to neuraminic acid, we have prepared three series of amphiphilic self-assembling 2-thio-neuraminic acid derivatives constituting aggregates in aqueous medium to take advantage of their multivalent effect. One of the series was prepared by the azide-alkyne click reaction, and the other two by the thio-click reaction to yield neuraminic acid derivatives containing lipophilic tails of different sizes and an enzymatically stable thioglycosidic bond. Two of the three bis-octyl derivatives produced proved to be active against influenza viruses, while all three octyl derivatives bound to hemagglutinin and neuraminidase from H1N1 and H3N2 influenza types.

• Klíčová slova
• aggregates, hemagglutinin, influenza, neuraminidase, sialic acid,
• MeSH
• chřipka lidská * farmakoterapie   MeSH
• hemaglutininové glykoproteiny viru chřipky metabolismus   MeSH
• hemaglutininy farmakologie   MeSH
• kyselina N-acetylneuraminová farmakologie   metabolismus   MeSH
• kyseliny neuraminové MeSH
• lidé MeSH
• neuraminidasa metabolismus   MeSH
• virus chřipky A, podtyp H1N1 * MeSH
• virus chřipky A, podtyp H3N2 MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• hemaglutininové glykoproteiny viru chřipky MeSH
• hemaglutininy MeSH
• kyselina N-acetylneuraminová MeSH
• kyseliny neuraminové MeSH
• neuraminidasa MeSH

BackgroundTimely treatment with neuraminidase inhibitors (NAI) can reduce severe outcomes in influenza patients.AimWe assessed the impact of antiviral treatment on in-hospital deaths of laboratory-confirmed influenza patients in 11 European Union countries from 2010/11 to 2019/20.MethodsCase-based surveillance data from hospitalised patients with known age, sex, outcome, ward, vaccination status, timing of antiviral treatment, and hospitalisation were obtained. A mixed effect logistic regression model using country as random intercept was applied to estimate the adjusted odds ratio (aOR) for in-hospital death in patients treated with NAIs vs not treated.ResultsOf 19,937 patients, 31% received NAIs within 48 hours of hospital admission. Older age (60-79 years aOR 3.0, 95% CI: 2.4-3.8; 80 years 8.3 (6.6-10.5)) and intensive care unit admission (3.8, 95% CI: 3.4-4.2) increased risk of dying, while early hospital admission after symptom onset decreased risk (aOR 0.91, 95% CI: 0.90-0.93). NAI treatment initiation within 48 hours and up to 7 days reduced risk of dying (0-48 hours aOR 0.51, 95% CI: 0.45-0.59; 3-4 days 0.59 (0.51-0.67); 5-7 days 0.64 (0.56-0.74)), in particular in patients 40 years and older (e.g. treatment within 48 hours: 40-59 years aOR 0.43, 95% CI: 0.28-0.66; 60-79 years 0.50 (0.39-0.63); ≥80 years 0.51 (0.42-0.63)).ConclusionNAI treatment given within 48 hours and possibly up to 7 days after symptom onset reduced risk of in-hospital death. NAI treatment should be considered in older patients to prevent severe outcomes.

• Klíčová slova
• EU, Influenza, antiviral treatment, clinic, epidemiology, fatal outcome, hospital, influenza virus, risk factors, surveillance,
• MeSH
• antivirové látky terapeutické užití   MeSH
• chřipka lidská * farmakoterapie   epidemiologie   MeSH
• guanidiny terapeutické užití   MeSH
• inhibitory enzymů terapeutické užití   MeSH
• lidé MeSH
• mortalita v nemocnicích MeSH
• neuraminidasa MeSH
• oseltamivir * terapeutické užití   MeSH
• senioři MeSH
• výsledek terapie MeSH
• zanamivir terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antivirové látky MeSH
• guanidiny MeSH
• inhibitory enzymů MeSH
• neuraminidasa MeSH
• oseltamivir * MeSH
• zanamivir MeSH

Saccharides form one of the major constituents of biological macromolecules in living organisms. Many biological processes including protein folding, stability, immune response and receptor activation are regulated by glycosylation. In this work, we optimized a capillary electrophoresis method with capacitively coupled contactless conductivity detection for the separation of eight monosaccharides commonly found in glycoproteins, namely D-glucose, D-galactose, D-mannose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-fucose, N-acetylneuraminic acid, and D-xylose. A highly alkaline solution of 50 mM sodium hydroxide, 22.5 mM disodium phosphate, and 0.2 mM CTAB (pH 12.4) was used as a background electrolyte in a 10 µm id capillary. To achieve baseline separation of all analytes, a counter-directional pressure of -270 kPa was applied during the separation. The limits of detection of our method were below 7 µg/ml (i.e., 1.5 pg or 1 mg/g protein) and the limits of quantification were below 22 µg/ml (i.e., 5 pg or 3 mg/g protein). As a proof of concept of our methodology, we performed an analysis of monosaccharides released from fetuin glycoprotein by acid hydrolysis. The results show that, when combined with an appropriate pre-concentration technique, the developed method can be used as a monosaccharide profiling tool in glycoproteomics and complement the routinely used LC-MS/MS analysis.

• Klíčová slova
• capillary electrophoresis, contactless conductivity detection, glycoproteins, hydrolysis, monosaccharides,
• MeSH
• acetylgalaktosamin MeSH
• acetylglukosamin MeSH
• cetrimonium MeSH
• chromatografie kapalinová MeSH
• elektroforéza kapilární metody   MeSH
• elektrolyty chemie   MeSH
• fetuiny MeSH
• fosfáty MeSH
• fukosa MeSH
• galaktosa MeSH
• glukosa MeSH
• glykoproteiny chemie   MeSH
• hydroxid sodný MeSH
• kyselina N-acetylneuraminová * MeSH
• mannosa MeSH
• monosacharidy * analýza   MeSH
• tandemová hmotnostní spektrometrie MeSH
• xylosa MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetylgalaktosamin MeSH
• acetylglukosamin MeSH
• cetrimonium MeSH
• elektrolyty MeSH
• fetuiny MeSH
• fosfáty MeSH
• fukosa MeSH
• galaktosa MeSH
• glukosa MeSH
• glykoproteiny MeSH
• hydroxid sodný MeSH
• kyselina N-acetylneuraminová * MeSH
• mannosa MeSH
• monosacharidy * MeSH
• xylosa MeSH

Alterations in oligosaccharides and types of sialic acid (SA) attachments have been associated with different pathological states. Matrix-assisted laser desorption mass spectrometry (MS) is commonly used for glycosylation studies. However, native sialylated glycans are suppressed or not detected during MS experiments. Consequently, different approaches have been employed to neutralize the negative charge of the carboxyl group. In this study, we present the advantage of phenylhydrazine (PHN) labeling for the detection and efficient discrimination of SA linkages when this derivatization follows alkyl esterification. As expected, PHN-labeled sialylated oligosaccharides with the 2,6-linkage type can be easily recognized according to the additional shift in mass corresponding to the presence of a methyl or ethyl group. Surprisingly, oligosaccharides with the 2,3-linked SA residue instead of a lactone were detected carrying the second PHN unit. This was beneficial as no further processing after esterification was needed to stabilize the lactone form. Moreover, during tandem mass experiments, all modified glycans produced favorable fragmentation patterns with a coherent recognition of SA linkages. Although both types of esterification, herein called the EST-PHN approach, provided comparable results, methylation exhibited marginally higher linkage specificity than ethyl esterification. The simplicity and effectiveness of the methodology are demonstrated on the model compound, sialyllactose, and its applicability for biological studies is presented on N-glycan profiling in the sera of lung cancer patients.

• MeSH
• esterifikace MeSH
• fenylhydraziny chemie   MeSH
• kyselina N-acetylneuraminová chemie   MeSH
• laktony MeSH
• lidé MeSH
• nádory plic * diagnóza   MeSH
• oligosacharidy * chemie   MeSH
• polysacharidy chemie   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fenylhydraziny MeSH
• kyselina N-acetylneuraminová MeSH
• laktony MeSH
• oligosacharidy * MeSH
• polysacharidy MeSH

The composition of a sample solvent has a crucial impact on separations in hydrophilic interaction liquid chromatography (HILIC). In this short communication, we studied the effect of an organic modifier in the sample solvent on the solubility of different tryptic glycopeptides of hemopexin and haptoglobin proteins. The results showed that the solubility of glycopeptides in solvents with a high acetonitrile content depends on the type of attached N-glycan. We observed lower solubility in larger glycans attached to the same peptide backbone, and we demonstrated that glycopeptides containing sialic acids precipitate more readily than those without sialic acid. Therefore, the sample solvent composition in HILIC must be carefully optimized for accurate quantitative data collection and for adequate separation.

• Klíčová slova
• Glycopeptides, Hydrophilic interaction liquid chromatography, Solubility,
• MeSH
• acetonitrily chemie   MeSH
• glykopeptidy analýza   chemie   izolace a purifikace   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kyselina N-acetylneuraminová chemie   MeSH
• polysacharidy chemie   MeSH
• rozpouštědla chemie   MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetonitrile MeSH Prohlížeč
• acetonitrily MeSH
• glykopeptidy MeSH
• kyselina N-acetylneuraminová MeSH
• polysacharidy MeSH
• rozpouštědla MeSH

Altered glycosylation is a universal feature of cancer cells and certain glycans are well-known markers of tumor progression. In this work we studied two glycan isomers, 2,3-sialyllactose (3-SL) and 2,6-sialyllactose (6-SL), frequently appearing in glycoproteins connected with cancer. A combination of square wave voltammetry and glycan modification with osmium(VI) N,N,N',N'-tetramethylethylenediamine (Os(VI)tem) allowed to distinguish between these regioisomers, since the 6-SL molecule can bind three Os(VI), while the 3-SL only two Os(VI) moieties, as experiments using capillary electrophoresis, inductively coupled plasma mass spectrometry and thin layer chromatography showed. A similar pattern of Os(VI)-modification was found for isomers of sialyl-N-acetyllactosamine and sialylgalactose. Covalent adducts of Os(VI)tem with glycans yielded three reduction voltammetric peaks. The ratio of peak I/peak II heights depends on the content of individual regioisomer in the sample. Our proposed approach allows the determination of isomer percentage representation in the mixture after one voltammogram recording. These results show a new appropriate method for the discrimination of glycan isomers containing terminal sialic acid important for distinguishing between cancerous and non-cancerous origin of biomarkers.

• Klíčová slova
• Chemical modification of carbohydrates, Glycan isomers, Mercury electrodes, Osmium(VI) complexes, Square wave voltammetry,
• MeSH
• elektrochemické techniky * MeSH
• komplexní sloučeniny chemie   MeSH
• kyseliny sialové analýza   chemie   MeSH
• laktosa analogy a deriváty   analýza   chemie   MeSH
• lidé MeSH
• osmium chemie   MeSH
• stereoizomerie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• komplexní sloučeniny MeSH
• kyseliny sialové MeSH
• laktosa MeSH
• N-acetylneuraminoyllactose MeSH Prohlížeč
• osmium MeSH

Sialic acid (SA), a family of acetylated derivatives of neuraminic acid, an acute phase reactant by itself. It usually occurs as a terminal component at the non-reducing end of carbohydrate chains of glycoproteins and glycolipids. SA participates in multiple physiological functions, such as cell-to-cell interactions, cell migration and proliferation. Diabetes mellitus (DM) is a chronic metabolic disorder characterized by rise in blood glucose level. Periodontitis is a chronic inflammatory disease of the periodontal tissue, leading to destruction of bone surrounding the tooth and ultimately tooth loss. There is a two way relationship between diabetes mellitus and periodontitis. Periodontitis is the sixth complication of diabetes along with retinopathy, nephropathy, neuropathy, macrovascular disease, and altered wound healing. Inflammatory mediators like interleukin-6 and tumor necrosis factor-alpha produced during periodontal inflammation can interfere with the actions of insulin receptors and worsen the glycemic control of diabetic patients. Periodontitis is a major cause of tooth loss, affecting over 300 million people and bacteria associated with periodontitis are also linked with systemic problems like endocarditis, atherosclerosis. Recent work has highlighted a major role for the host sugar sialic acid in the biofilm physiology and host-pathogen interactions of T. forsithya, a key periodontal pathogen. There exists a need for a biomarker, for early detection of disease evolution and more robust therapy efficacy measurements. Serum sialic acids were estimated in Indian population by diphenylamine method and Thiobarbituric acid method. The average values were 68 ± 2.6 mg percent by DPA method and 56 ± 5 mg percent by TBA (thiobarbituric acid assay) method. Age and sex showed no influence on serum sialic acid level. Objectives of the present study was to compare (TSSA) level in healthy subjects, subjects with (CMP) with and without (NIDDM) and its effect on non-surgical periodontal therapy. In the present study, the participants were divided into three groups: Group A, B and C. Group A consists of systemically healthy subjects, Group B consists of subjects with (CMP) while Group C consists of subjects with (CMP) with (NIDDM) and results of this study indicated that, at baseline, there were significant differences between Group A, B and Group C with respect to all the clinical parameters, including (GI), (OHI-S), (PPD), (CAL), (TSSA) and (HbA1c) levels. Thus (TSSA) level could be considered as novel biomarker in the progression of periodontal disease and diabetic status. Periodontitis could be considered as a potential, modifiable, and independent risk factor for the development of diabetes. Early detection of elevated (TSSA) level may help in interpreting the progression of periodontitis, risk of development of diabetes mellitus in future and also to prevent complications.

• Klíčová slova
• acute phase proteins, biomarker, chronic periodontitis, diabetes mellitus, non-surgicalperiodontal therapy, total serum sialic acid,
• MeSH
• biologické markery krev   MeSH
• diabetes mellitus 2. typu krev   komplikace   MeSH
• dospělí MeSH
• komplikace diabetu krev   MeSH
• kyselina N-acetylneuraminová krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• parodontitida krev   komplikace   terapie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologické markery MeSH
• kyselina N-acetylneuraminová MeSH

In recent decades, it has become clear that most of human proteins are glycosylated and that protein glycosylation plays an important role in health and diseases. At present, simple, fast and inexpensive methods are sought for clinical applications and particularly for improved diagnostics of various diseases, including cancer. We propose a label- and reagent-free electrochemical method based on chronopotentiometric stripping (CPS) analysis and a hanging mercury drop electrode for the detection of interaction of sialylated protein biomarker a prostate specific antigen (PSA) with two important lectins: Sambucus nigra agglutinin (SNA) and Maackia amurensis agglutinin (MAA). Incubation of PSA-modified electrode with specific SNA lectin resulted in an increase of CPS peak H of the complex as compared to this peak of individual PSA. By adjusting polarization current and temperature, PSA-MAA interaction can be either eliminated or distinguished from the more abundant PSA-SNA complex. CPS data were in a good agreement with the data obtained by complementary methods, namely surface plasmon resonance and fluorescent lectin microarray. It can be anticipated that CPS will find application in glycomics and proteomics.

• Klíčová slova
• A prostate specific antigen, Chronopotentiometric analysis, Lectin-glycoprotein interaction, Mercury electrode, Sialylated glycan isomers,
• MeSH
• aglutininy metabolismus   MeSH
• bez černý chemie   MeSH
• elektrická vodivost * MeSH
• elektrochemie MeSH
• kyselina N-acetylneuraminová metabolismus   MeSH
• Maackia chemie   MeSH
• prostatický specifický antigen chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aglutininy MeSH
• kyselina N-acetylneuraminová MeSH
• prostatický specifický antigen MeSH