Publications by authors named "Sergeyev B"

Total serum IgG level is a surrogate marker of hepatitis C (HC) severity. Antibodies (Abs) to microbial glycans could be markers of HC severity caused by the translocation of microbial products. The level of anti-glycan (AG) Abs was analysed in serum samples of patients ( = 128) with chronic HC in ELISA using fourteen synthetic glycans present in microbes and adhesins to evaluate the association of Abs with clinical parameters and the efficacy of antiviral treatment.

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Background: The serum levels of IgG antibodies reactive to glycoconjugates (TF, Tn and αGal) were found to be associated with prognosis of gastrointestinal cancer patients.

Aim: To study the relation between the levels of serum antibodies to TF-pAA, Tn-PAA and αGal-PAA polyacrylamide-based glycoconjugates and survival in breast cancer.

Materials And Methods: The preoperative level of IgG antibodies was analysed in the serum of patients (n = 59) using ELISA with polyacrylamide-glycoconjugates namely, TF-pAA (amide-type), and ethanolamide-conjugates Tn-PAA and αGal-PAA.

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Background: The Russian human immunodeficiency virus (HIV) epidemic among people who inject drugs (PWID) originated in Kaliningrad, but research into risk behaviours among PWID has been lacking. The potential for heterosexual spread has not been analysed.

Methods: A sample of PWID was accrued using two methods.

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Aim: To study whether alterations in the sialylation of antibodies (Ab) specific to the Thomsen-Friedenreich (TF) glycotope have a diagnostic and prognostic potential in gastric cancer.

Methods: Serum samples were taken from patients with gastric carcinoma (n = 142) and controls (n = 61). The level of TF-specific antibodies and their sialylation was detected using ELISA with synthetic TF-polyacrylamide conjugate as antigen and sialic acid-specific Sambucus nigra agglutinin (SNA).

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Unlabelled: The elevated anti-GalNAcβ IgG level of serum was shown to be associated with the significantly better survival of patients with gastrointestinal cancer.

Aim: To characterize the specificity of IgG antibodies to GalNAcβ-terminated glycans of long-term gastric cancer survivors.

Methods: Serum antibodies and affinity-isolated antibodies were analysed by the indirect and competitive ELISA using glycan-polyacrylamide (PAA) conjugates as well as by isoelectric focusing and Western blotting.

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Objective: To evaluate the relation of the level of serum anti-TF, -Tn and -αGal carbohydrate antibodies to survival in gastrointestinal cancer patients.

Methods: The level of anti-TF (Thomsen-Friedenreich antigen), -Tn and -αGal IgG was analysed in the serum of patients with gastric (n = 83) and colorectal (n = 51) cancers in the long-term follow-up, using ELISA with polyacrylamide glycoconjugates. To evaluate overall survival and the risk of death, the Kaplan-Meier method and the Cox proportional hazards model were used in the univariate analysis of patients groups.

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Unlabelled: Serum anti-(GalNAcβ) and anti-para-Forssman disaccharide (PF(di), GalNAcβ1--3GalNAcβ) IgG levels were earlier found to be related to histological grading and progression of gastrointestinal cancer.

Aim: To study the relation of serum antibodies level to survival in patients with gastrointestinal cancer.

Methods: The level of anti-GalNAcβ, and PF(di) IgG was analysed in the serum of patients with gastric (n = 78) and colorectal (n = 48) cancers in the long-term follow-up using ELISA with polyacrylamide glycoconjugates.

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Aim: To study whether alterations in the glycosylation of immunoglobulin G (IgG) specific to the Thomsen-Friedenreich glycotope (TF) have diagnostic and prognostic potential in gastric cancer.

Methods: Serum samples were obtained from patients with histologically verified gastric carcinoma (n = 89), healthy blood donors (n = 40), and patients with benign stomach diseases (n = 22). The lectin-enzyme-linked immunosorbent assay-based glycoprofiling of TF-specific IgG (anti-TF IgG) was performed using synthetic TF-polyacrylamide conjugate as antigen, total IgG purified by affinity chromatography on protein G sepharose, and lectins of various sugar specificities: mannose-specific concanavalin A (ConA), fucose-specific Aleuria aurantia lectin (AAL) and sialic acid-specific Sambucus nigra agglutinin (SNA).

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The IgG Fc glycans strongly influence the Fcγ receptor interactions and Fc-mediated effector mechanisms. Changes in the structure of IgG glycans are associated with various diseases, such as infections and autoimmunity. However, the possible role of Fc glycans in tumor immunity is not yet fully understood.

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The majority of early cases of HIV in Russia were among men who have sex with men (MSM). Despite this and the current resurgence of HIV among MSM globally, little systematic work has been done to assess current HIV risks. We conducted a rapid assessment of HIV and associated risk behaviors among MSM in Russia.

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Changes in the glycosylation in cancer may lead to an aberrant expression of A, B incompatible or xenogeneic blood group related antigens. To characterize the specificity of IgG antibodies to A, B, and related glycans in sera of gastrointestinal cancer patients, serum probes and affinity-isolated antibodies were analyzed in the indirect and competitive ELISA using a set of homogenous polyacrylamide (PAA) glycoconjugates. Monoreactive antibodies recognizing A(di) (I) and cross-reactive antibodies to A(di)/B(di)/B(tri) (II) or A(di)/A(tri)/Fs(di)/Core5 (III) were affinity-isolated on A(di)-PAA-Sepharose.

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Aim: To study the influence of tumor removal on the serum level of IgG antibodies to tumor-associated Thomsen-Friedenreich (TF), Tn carbohydrate epitopes and xenogeneic alphaGal, and to elucidate on the change of the level during the follow-up as well as its association with the stage and morphology of the tumor and the values of blood parameters in gastrointestinal cancer.

Methods: Sixty patients with gastric cancer and 34 patients with colorectal cancer in stages I-IV without distant metastases were subjected to follow-up. The level of antibodies in serum was determined by the enzyme-linked immunosorbent assay (ELISA) using synthetic polyacrylamide (PAA) glycoconjugates.

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Unlabelled: Earlier we found two unusual IgG-antibody specificities to GalNAc beta and GalNAc beta1-3GalNAc beta (para-Forssman disaccharide, PFdi) carbohydrate ligands in human serum. The aim of the study was to evaluate whether elevated antibody levels are related to the progression of gastrointestinal cancer and the histopathological grading.

Methods: Specific IgG levels were tested in 159 patients with gastric cancer, 88 patients with colorectal cancer and 96 blood donors by the ELISA using synthetic polyacrylaamide (PAA) conjugates, GalNAc beta-PAA and PFdi-PAA.

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The TF, Tn, and SiaTn glycotopes are frequently expressed in cancer-associated mucins. Antibodies to these glycotopes were found in human serum. A set of polyacrylamide (PAA)--based glycoconjugates was applied to the direct and competitive enzyme-linked immunosorbent assays (ELISA) to characterize the specificity of serum IgG antibodies.

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The survival of patients with histologically verified gastric carcinoma at stage I (n = 44) and stage II (n = 43) was analysed by the Kaplan-Meier method depending on H. pylori serological status and a level of IgG and IgM antibody to tumor-associated Thomson-Friedenreich antigen (T Ag). In cancer patients at stage I, significantly better survival for H.

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Kinetics of photolysis of the antibiotic tetracycline (TC) during irradiation at 365 nm was studied in three buffer solutions usually used for studies on TC binding to its main cell targets--a transcriptional repressor protein TetR and to the ribosome. These buffer solutions contain magnesium ions and an antioxidant--mercaptoethanol or dithiothreitol. The rate of TC photolysis was maximal in medium which contained 14 mM mercaptoethanol and 5 mM magnesium ions.

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In order to study effects of environmental contamination, a suite of biomarkers were measured over the period 1996 to 1999 in livers of flounder (Platichthys flesus) from two urban embayments and one non-urban reference site of the Gulf of Finland in the vicinity of Tallinn, Estonia. Total cytochrome P450 (CYP) level, aryl hydrocarbon hydroxylase (AHH), 5-aminolevulinic acid synthetase (ALA-S), and heme synthetase (HEM-S) activities were quantified by means of spectrophotometry. These data were compared to results obtained in 1994 for the same biomarkers at one of the urban embayments and the non-urban site, as measured by the same protocols.

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