OBJECTIVE: The monitoring of influenza virus resistance is a routine part of influenza virus surveillance conducted by the National Reference Laboratory for Influenza and Non-Influenza Respiratory Viral Diseases (NRL/INI) at the National Institute of Public Health (NIPH). The aim is to detect neuraminidase inhibitor (oseltamivir) resistance in patients diagnosed with influenza. MATERIAL AND METHODS: A total of 326 influenza virus isolates from tissue culture were included in the study. They were obtained from inpatient and outpatient nasopharyngeal swabs which were referred to the NRL/INI during the seasons 2013/2014 to 2019/2020 and turned out to be RTPCR (reverse transcription polymerase chain reaction) positive for RNA (ribonucleic acid) of influenza virus A or B. The MDCK (Madin-Darby canine kidney) tissue culture cells were used for virus isolation from nasopharyngeal swabs. Oseltamivir resistance was tested using the NA-Star Influenza Neuraminidase Inhibitor Resistance Detection Kit (Applied Biosystems, Foster City, CA). RESULTS: Nine of 326 positive specimens were oseltamivir resistant. Resistant strains showed IC50 values 100 times as high on average as those in oseltamivir sensitive strains. CONCLUSIONS: Monitoring influenza virus resistance is helpful in controlling reasonable prescription of antivirals and thus becomes an integral part of influenza virus surveillance. Antiviral resistance monitoring is necessary not only in hospitalized patients on antivirals but also in symptomatically treated outpatients as the detection of antiviral drug resistant strains in the latter group can suggest the emergence and/or spread of antiviral drug resistance in the population.
- Klíčová slova
- Mutation, influenza A and B, mutation, oseltamivir, resistance, surveillance,
- MeSH
- antivirové látky farmakologie terapeutické užití MeSH
- chřipka lidská * farmakoterapie MeSH
- lidé MeSH
- neuraminidasa genetika farmakologie terapeutické užití MeSH
- Orthomyxoviridae * MeSH
- oseltamivir farmakologie terapeutické užití MeSH
- psi MeSH
- virová léková rezistence MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- psi MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antivirové látky MeSH
- neuraminidasa MeSH
- oseltamivir MeSH
This study focuses on design, synthesis and in vitro evaluation of inhibitory potency of two series of sialylmimetic that target an exosite ("150-cavity") adjacent to the active site of influenza neuraminidases from A/California/07/2009 (H1N1) pandemic strain and A/chicken/Nakorn-Patom/Thailand/CU-K2-2004 (H5N1). The structure-activity analysis as well as 3-D structure of the complex of parental compound with the pandemic neuraminidase p09N1 revealed high flexibility of the 150-cavity towards various modification of the neuraminidase inhibitors. Furthermore, our comparison of two methods for inhibition constant determination performed at slightly different pH values suggest that the experimental conditions of the measurement could dramatically influence the outcome of the analysis in the compound-dependent manner. Therefore, previously reported Ki values determined at non-physiological pH should be carefully scrutinized.
- Klíčová slova
- Click chemistry, Crystal structure, Influenza neuraminidase, Oseltamivir,
- MeSH
- lidé MeSH
- neuraminidasa farmakologie terapeutické užití MeSH
- oseltamivir farmakologie terapeutické užití MeSH
- virus chřipky A, podtyp H1N1 patogenita MeSH
- virus chřipky A, podtyp H5N1 patogenita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- neuraminidasa MeSH
- oseltamivir MeSH
The total serum activity of gamma-glutamyl transpeptidase (GGT) was shown to increase with the growth of transplantable B16 and S91 melanomas in inbred mice. In an effort to define the source of the GGT shed into the bloodstream the physicochemical characteristics of the partially purified GGT isoforms from liver, serum and B16 melanoma were compared. The molecular weights of the serum and melanoma isoforms were identical (86 kDa) and differed from that of the liver isoform (69 kDa). In polyacrylamide gel electrophoresis the serum and melanoma isoforms had a similar mobility which exceeded that of the liver enzyme. Treatment of the enzyme preparations with neuraminidase removed the differences in the electrophoretic mobility of the three GGT isoforms studied. On ion exchange chromatography on a DEAE-Spheron 300 LC column the melanoma and serum isoforms had an affinity to the sorbent unlike the liver isoform. Our observations suggest that melanoma cells express a sialoform of GGT which is responsible for an increase in the total GGT serum activity. Biochemical and histochemical analyses did not reveal any increase in liver GGT production associated with melanoma development. Detection of the GGT isoform of tumour origin in sera ranks GGT among the specific melanoma markers.
- MeSH
- chromatografie iontoměničová MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- gama-glutamyltransferasa účinky léků izolace a purifikace metabolismus MeSH
- izoenzymy účinky léků izolace a purifikace metabolismus MeSH
- játra enzymologie MeSH
- kyselina N-acetylneuraminová metabolismus MeSH
- melanom experimentální krev enzymologie patologie MeSH
- molekulová hmotnost MeSH
- myši inbrední C57BL MeSH
- myši inbrední DBA MeSH
- myši MeSH
- neuraminidasa farmakologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- gama-glutamyltransferasa MeSH
- izoenzymy MeSH
- kyselina N-acetylneuraminová MeSH
- neuraminidasa MeSH
The effect of the removal of the influenza virus receptor (N-acetylneuraminic acid) from the erythrocyte membrane by neuraminidase (RDE = receptor destroying enzyme) on the biophysical properties of the cell membrane has been examined using a fluorescent polarization technique. Diphenylhexatriene (DPH) was used as a fluorescent probe for structural ordering in the core of the membrane. A statistically significant decrease in the steady state values of DPH anisotropy was observed in membranes treated with RDE as compared to control. The anisotropy decrease reflected a reduced ordering of the hydrocarbon region of the erythrocyte membrane as well as an increase of its fluidity. An increase of membrane fluidity evoked by the action of influenza virus neuraminidase may play a significant role in the process of influenza virus penetration into the susceptible cell by endocytosis.
- MeSH
- anizotropie MeSH
- erytrocytární membrána virologie MeSH
- fluidita membrány * MeSH
- neuraminidasa farmakologie MeSH
- virové receptory účinky léků fyziologie MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- neuraminidasa MeSH
- virové receptory MeSH
Three related alpha-protease inhibitors, PI2 I, PI3 C and PI4 C2, of blood serum of the pig (Sus scrofa) were isolated. PI2 I inhibited both trypsin and chymotrypsin; PI3 C and PI4 C2 strongly inhibited chymotrypsin, but did not significantly inhibit trypsin. By using SDS-PAGE, the three proteins were found to be composed of single polypeptide chains, and molecular weights were 63,000 for PI2 I, 58,000 for PI3 C and 64,000 for PI4 C2. All three proteins were shown to be glycoproteins. In PI3 C, eight sialic acid residues were found, and in PI4 C2 (similarly as in PI2 F) 10-11 residues were found. Amino acid composition as well as N-terminal sequences of the three proteins were very similar, indicating close homology. Comparison of these partial amino acid sequences with the cDNA-deduced amino acid sequence of pig alpha-antichymotrypsin (AACT; Buchman, 1989, GenBank, Accession No. M29508) revealed great similarities, the sequence of PI2 I being virtually identical with the pig AACT. On the basis of all available results, PI2 is proposed to be pig AACT, an orthologue of human AACT.
- MeSH
- alfa-1-antichymotrypsin krev chemie MeSH
- aminokyseliny analýza MeSH
- chymotrypsin antagonisté a inhibitory MeSH
- inhibitory proteas krev MeSH
- inhibitory trypsinu krev MeSH
- komplementární DNA chemie MeSH
- koncentrace vodíkových iontů MeSH
- krevní proteiny chemie MeSH
- molekulární sekvence - údaje MeSH
- molekulová hmotnost MeSH
- neuraminidasa farmakologie MeSH
- prasata MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
- Názvy látek
- alfa-1-antichymotrypsin MeSH
- aminokyseliny MeSH
- chymotrypsin MeSH
- inhibitory proteas MeSH
- inhibitory trypsinu MeSH
- komplementární DNA MeSH
- krevní proteiny MeSH
- neuraminidasa MeSH
The effect of electrostatic forces on the adhesion of LEP-19 diploid embryonal fibroblasts, Hep-2 laryngeal carcinoma cells, Raji lymphoblastoma cells and Sp 2/0 myeloma cells was examined in vitro. Adhesivity of all tested cell lines was higher on the cationized glass than on untreated or anionized glass. The negatively charged sialic acids on the cell surface play a role in cell adhesion. The participation of electrostatic interaction is independent of the energy metabolism in serum-free conditions.
- MeSH
- anionty * MeSH
- buněčná adheze * MeSH
- chemické jevy MeSH
- fibroblasty fyziologie MeSH
- fyzikální chemie MeSH
- kationty MeSH
- kultivační média bez séra MeSH
- kyseliny sialové fyziologie MeSH
- lidé MeSH
- mikrosféry MeSH
- nádorové buňky kultivované MeSH
- nádorové kmenové buňky fyziologie MeSH
- neuraminidasa farmakologie MeSH
- povrchové vlastnosti MeSH
- sklo MeSH
- teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- anionty * MeSH
- kationty MeSH
- kultivační média bez séra MeSH
- kyseliny sialové MeSH
- neuraminidasa MeSH
In a group of 144 children (six months to 15 years) three doses vaccine were administered. The latter contains the main strains of the influenza type A and strain type B. From the clinical evaluation ensued that this vaccine in children is areactogenic even after repeated doses. The morbidity was followed up for 18 months and during this period in the immunized communities no case of influenza was recorded. The antibody levels were assessed by the haemagglutination-inhibition test (HIT) and the enzyme test (NIT) The assessed HI titres were high after the second and third dose, in particular as regard subtype H3N2 and H1N1. The titres against subtype H2N2 and type B were markedly lower. Antibodies against neuraminidase were highest against subtype N1 and type B, lowest against N2. The dynamics of the formation of antineuraminidase antibodies was similar as that of haemagglutination-inhibition antibodies. Based on these results the vaccine is evaluated as very satisfactory and after approval by the Ministry of Health and Social Affairs this vaccine will be used for a field trial in 1-2 thousand children where above all the protective effect of the vaccine will be investigated. This vaccine is intended for children, with the aim to induce complex immunity against influenza.
- MeSH
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- neuraminidasa farmakologie MeSH
- očkovací schéma MeSH
- předškolní dítě MeSH
- protilátky virové analýza MeSH
- testy inhibice hemaglutinace MeSH
- vakcíny proti chřipce aplikace a dávkování škodlivé účinky imunologie MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- předškolní dítě MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Názvy látek
- neuraminidasa MeSH
- protilátky virové MeSH
- vakcíny proti chřipce MeSH
The adherence of group B streptococci (GBS) of serotypes Ia, II and III to human vaginal cells was studied in vitro. The adherence was not dependent on the viability of bacteria; killing of GBS by UV irradiation or glutaraldehyde treatment did not inhibit the adherence. Killing of GBS by heating to 56 degrees C for 1 h led to a pronounced decrease of adherence, demonstrating the thermosensitivity of the GBS structures involved. The protein nature of these structures was proved by a significant reduction of adherence after pretreatment of GBS with trypsin or pepsin. Pretreatment of GBS with sialidase had no influence on the adherence. Such a pretreatment of vaginal cells caused an increase of adherence showing that the receptors on epithelial cells may be partly masked by sialic acid.
- MeSH
- bakteriální adheze * účinky léků účinky záření MeSH
- glutaraldehyd farmakologie MeSH
- lidé MeSH
- neuraminidasa farmakologie MeSH
- pepsin A farmakologie MeSH
- Streptococcus agalactiae patogenita MeSH
- trypsin farmakologie MeSH
- ultrafialové záření MeSH
- vagina mikrobiologie MeSH
- vysoká teplota MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- glutaraldehyd MeSH
- neuraminidasa MeSH
- pepsin A MeSH
- trypsin MeSH
The heterogeneity of dipeptidyl peptidase IV (EC 3.4.14.5) was investigated in normal human serum. Thin-layer analytical isoelectric focusing revealed the presence of multiple molecular forms of the enzyme, their isoelectric points being in the pH range of 3.30-4.25. The maximum of enzyme activity appeared around pH 3.50. After treatment with neuraminidase the pI shifted to 4.70-5.40 with two maxima at pH 5.00 and 5.15. The Triton X-100 solubilized as well as the papain-treated-Triton X-100 solubilized enzyme from the whole human adult jejunal biopsy were also found to be heterogeneous. They focused--both before and after neuraminidase treatment--at pH values different from those of the enzyme of normal human serum. There was almost no pI shift after neuraminidase treatment of the intestinal enzyme from adult enterobiopsy. Electrophoresis in continuous polyacrylamide gradient gels as well as gel chromatography on Bio-Gel A-1.5m revealed two molecular forms of dipeptidyl peptidase IV in normal human serum. The estimated relative molecular mass of the major enzyme form was 250 000 in both the separation techniques used. On the other hand, the apparent relative molecular mass of the minor enzyme form was 450 000 as assessed by gradient gel electrophoresis, and 550 000, when estimated by gel chromatography. The Km values for glycyl-L-proline-4-nitroanilide as substrate with the major and minor forms of the serum enzyme were 1.60 +/- 0.39 X 10(-4) mol/l and 1.60 +/- 0.13 X 10(-4) mol/l, respectively. Our results indicate that the dipeptidyl peptidase IV in normal human serum is a heterogeneous enzyme as far as its charge and molecular size are concerned.
- MeSH
- dipeptidylpeptidasy a tripeptidylpeptidasy krev MeSH
- elektroforéza v polyakrylamidovém gelu MeSH
- endopeptidasy krev MeSH
- gelová chromatografie MeSH
- izoelektrický bod MeSH
- izoenzymy krev MeSH
- jejunum enzymologie MeSH
- kinetika MeSH
- lidé MeSH
- molekulová hmotnost MeSH
- neuraminidasa farmakologie MeSH
- střevní sliznice enzymologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dipeptidylpeptidasy a tripeptidylpeptidasy MeSH
- endopeptidasy MeSH
- izoenzymy MeSH
- neuraminidasa MeSH
- MeSH
- aktivace lymfocytů MeSH
- erytrocyty účinky léků MeSH
- hemolyticko-uremický syndrom krev diagnóza imunologie MeSH
- kojenec MeSH
- lidé MeSH
- neuraminidasa farmakologie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- kazuistiky MeSH
- Názvy látek
- neuraminidasa MeSH
