Search

INTRODUCTION. The issues of treating patients with acute fluid collections and postnecrotic cysts are still relevant at the present time. Optimization of the tactics of treatment of patients at the early stages of the formation of postnecrotic cysts makes it possible to reduce the percentage of complications.The OBJECTIVE was to develop diagnostic criteria for the formation of a cyst capsule at the early stages of acute pancreatitis, to determine the optimal timing and options for transgastric drainage of cysts.METHODS AND MATERIALS. The results of treatment of 62 patients were analyzed. All patients underwent computed tomography with bolus contrast and endoscopic ultrasonography. There were 2 groups of patients who underwent surgical treatment in the early and late periods. The results of endoscopic transgastric drainage of postnecrotic pancreatic cysts were analyzed.RESULTS. Based on the analysis of the results of treatment of patients with postnecrotic pancreatic cysts and acute peripancreatic fluid collections, the data of multispiral computed tomography and endoscopic ultrasonography at the stages of cyst formation, options and optimal timing of endoscopic transgastric drainage were determined. Causes of complications accompanying this method were identified and analyzed. The technique of transgastric drainage has been improved, methods for the prevention of complications have been proposed.CONCLUSION. The obtained results make it possible to recommend diagnostic criteria and a treatment algorithm for use in clinical practice.

We propose a method of interperiod signal processing, which is based on the projection Doppler filterting method and used for selection of moving targets. The scheme of using the algorithm of the proposed method for signal processing is presented. The efficiency of this algorithm is assessed with regard to the optimal algorithm of matched filtering for various lengths of signal sampling.

α2,3-Sialylation of the lactosamine type N-glycans with trans-sialidase from Trypanosomacruzi is reported. Trans-sialidase (160 kDa, pI 5.35–5.65) and its catalytic fragment (70 kDa, pI 6.0–6.3) were isolated from T. сruzi cells and immobilized on ConA-Sepharose. The resulting preparation retained its activity for several months and was repeatedly used for obtaining mono-, di-, tri-, and tetrasialylated 7-amino-4-metylcoumarin-labeled oligosaccharides with various numbers of antennas and for α2,3-sialylation of glycans within glycoproteins and neoglycoconjugates.

Alpha2,3-sialylation of the lactosamine type N-glycans with trans-sialidase from Trypanosoma cruzi is reported. Trans-sialidase (160 kDa, pI 5.35-5.65) and its catalytic fragment (70 kDa, pI 6.0-6.3) were isolated from T. cruzi cells and immobilized on ConA-Sepharose. The resulting preparation retained activity for several months and was repeatedly used for obtaining mono-, di-, tri-, and tetrasialylated 7-amino-4-metylcoumarine-labeled oligosaccharides with various numbers of antennas and for alpha2,3-sialylation of glycans within glycoproteins and neoglycoconjugates.

The mechanisms of the antiproliferative effect of α1-acid glycoprotein (AGP) isolated from the blood of healthy donors (nAGP) and from the ascitic fluid of patients with stomach cancer (aAGP) are studied. Three fractions of AGP are divided into 3 groups according to their ability to bind to concanavalin A (ConA): AGP not binding to ConA (AGP-1) and AGP weakly (AGP-2) and strongly (AGP-3) binding to ConA. It is shown that native preparation of aAGP has a more potent inhibitory effect on lymphocyte proliferation than native preparation of nAGP. The most potent inhibitory effect is exerted by AGP-3. Native preparation of aAGP does not affect the secretion of interleukin-2 (IL-2) by lymphocytes, whereas AGP-1 inhibits this process. The weakly bound fraction has a stimulatory effect both on the proliferative response and on IL-2 secretion.

Self carbohydrate-mediated dimerization of glycoprotein angiotensin-converting enzyme (ACE) was demonstrated. The dimerization was studied in the reverse micelle experimental system as a model of biomembrane situation. Asialo-ACE or agalacto-ACE was able to form a dimer, whereas deglycosylated ACE and sequentially desialylated and degalactosylated ACE failed to dimerize. ACE-ACE interaction was competitively inhibited by Neu5Ac- or Gal-terminated saccharides. The results have allowed us to propose the existence of carbohydrate-recognizing domain (CRD) on ACE molecule. The structural requirements of this CRD were estimated based on the ability of saccharides to inhibit ACE dimerization. The most effective monosaccharides with equal inhibition potencies were shown to be galactose (as GalbetaOMe) and N-acetylneuraminic acid (as Neu5AcalphaOMe). Among oligosaccharides, the most effective ones were found to be 3'SiaLac and, especially, the whole pool of ACE oligosaccharide chains and biantennae complex oligosaccharide chains of other glycoproteins. Bovine and human ACEs were shown to be similar in terms of recognition of carbohydrates.

Systemic scleroderma (SSd) is a connective tissue disorder accompanied by generalized fibrosis. A disturbance of the synthesis and production of matrix glycoproteins, such as collagens, fibronectin, and proteoglycans, by connective tissue cells is typical for this disease. We previously demonstrated a decrease in the ganglioside content of cultured skin fibroblasts from patients with SSd. In this work the contents of sialoglycoproteins and sialoglycolipids in blood sera of patients with SSd were estimated. Simultaneously, the level of asialofetuin-sialyltransferase activity in blood plasma of three groups of patients--those with SSd, Raynaud's phenomenon, and with localized scleroderma--was investigated. CMP-5-acetamido-9-deoxy-9-fluoresceinylthioureidoneuraminic acid was used as a substrate for the enzyme assay. It was shown that the concentration of total sialic acid was increased and the concentration of lipid-bound sialic acid was slightly decreased in the blood sera of patients with SSd. A correlation between the lipid-bound sialic acid level and the severity of disease was observed; there was no correlation between severity of disease and total sialic acid. Sialyltransferase assay showed a decrease in the activity level in all three groups of patients. The greatest decrease (2-fold) of this activity was observed in patients with Raynaud's phenomenon. Our data suggest that in SSd and similar diseases the process of glycoconjugate sialylation is disturbed. These changes may considerably affect the mechanisms of regulation of metabolism and cellular interactions.

The immunochemically pure alpha 1-acid glycoprotein (aAGP) from ascitic fluid of patients with stomach cancer was separated by chromatography on Con A-Sepharose into Con A-nonbound (aAGP-1, 43, 5 kDa, 70%) and Con A-bound (aAGP-2, 41.5 kDa, 24% and aAGP-3, 40.0 kDa, 5%) forms, differing in the monosaccharide composition. Comparative study of structures of their N-carbohydrate chains with the aid of the HPLC of fluorescence-labelled oligosaccharides showed that the molecular forms differ by the ratio of the di-, tri-, and tetraantennary carbohydrate N-chains of a complex type. The molecular forms of aAGP differ from nAGP by amounts of Le(x)-fragments and agalacto-oligosaccharides.

Translocation of carbohydrate glycoprotein N-chains onto soluble polyacrylamide was proposed as a method for studying the biological role of carbohydrate chains. N-linked carbohydrate chains of alpha 1-acid glycoprotein (AGP) were aminated at the reducing GlcNAc moiety and covalently attached to polyacrylamide (PAA). Thus "pseudo-AGP" was obtained where peptide core was replaced with PAA. The synthetic model mimics AGP by M(r) and carbohydrate content as well as the ratio of tetra-, tri- and diantennary and mono-, di-, tri- and tetrasialo chains. It was shown that the conjugate inhibits proliferation of lymphocytes like the parent AGP. Therefore, the property of AGP to inhibit the lymphocyte proliferation is attributed to its carbohydrate chains, whereas peptide core serves as carrier providing polyvalent interaction of multiple carbohydrate chains with cell.

Albumin-like glycoprotein (Gp66) with a molecular mass of 66 kDa has been isolated from human fetal tissue by size-exclusion, ion-exchange chromatography and reverse-phase HPLC. Reactivity of Gp66 with antiserum raised against the major protein components fraction of human fetal serum was observed. The N-terminal 35 amino acid residues of Gp66 were identical to human serum albumin. Meanwhile Gp66 differed from albumin by a/ the presence of 3-5 Trp residues instead of 1 according to fluorescence and UV-spectra, b/ the glycosylation pattern: bi-, tri-, and tetraantennary sialooligosaccharides of a complex type were present. Isoelectric focusing revealed 4 isoforms (pI ranging within 4.8 to 5.1) of Gp66. Gp66 (but not asialo-Gp66) was able to inhibit the cytotoxic effect of TNF against the tumor cell line L929. Inhibition of WEHI-3 and L929 tumor cells proliferation by Gp66 was similar to that of albumin.

This paper presents the layout of the experimental unit for determining the self-ignition conditions based on the possibility of self-ignition of an acetylene-oxygen mixture on compressing it in a partially enclosed body. Ignition in the detonation chamber is fixed by photographic recorders type FD-3 and gages TUR 3514. The required volume of the lower chamber was determined by varying the distance from the upper section of the lower chamber to the face of the piston. In the first stage of the study, the probability of self-ignition was determined in relation to the initial volume of the chamber for 30% acetylene-oxygen mixture. The data presented could be used for designing flame interceptors. The permissible gas volume under the membrane is selected from the extent of the membrane travel in relation to the resistance of the protective device to the gas flow.

This paper describes a testing procedure when developing a system for the protection of acetylene stations from explosions. The procedure allows one to assess the influence of individual elements of the system on the speed of response depending on different factors, as well as to shorten the time required for the wearing out of individual parts without affecting the quality of the investigations. Passage of the explosion flame past a photosensor can be simulated by illuminating it with a light pulse; this was used as the basis for the proposed procedure. The stand for the explosion test is illustrated and consists of the photographic camera and the support with the lamp, mounted on a table equipped with a measuring scale. The test stand can also be used to test any element of the electronic scheme of the system which is triggered off by a light pulse, simulating the passage of an explosion wave.

4-(N-Methylcoumarin-7-yl) glycamines were employed in studying asparagine-linked carbohydrate chains of acid desialylated fetuin. The procedure was optimised for the reductive amination of oligosaccharides with 7-amino-4-methylcoumarin in the presence of Na(CN)BH3 to lead to oligosaccharide glycamines (AMC-OS). AMC-OS were obtained from dextran oligosaccharides and from oligosaccharides released by hydrazinolysis of asparagine-linked sugar chains of asialofetuin. Reverse-phase HPLC and exclusion HPLC with fluorimetric quantitation of AMC-OS is described. TSK Gel 2000 SW column was calibrated using dextran AMC-OS to give linear relationship ln Ni = k(ti/tr)+b, where ti/tr is retention time of the AMC-OS relatively to the reference AMC-trisaccharide, and Ni is calibration unit value, characterizing molecular size of AMC-OS. Three AMC-OS, Gal3GlcNAc3Man3GlcNAc2-AMC (I) and (II), and Gal2GlcNAc3Man3GlcNAc2AMC (III), were obtained from asialofetuin in a molar ration of 1:1.8:0.1. Acid treatment of AMK-OS (II) in desialylation conditions also gave AMC-OS (III), thus suggesting a partial degalactosylation of the glycoprotein sugar chains during the desialylation. Consequent digestion of AMC-OS (II) and (III) with Jack bean beta-galactosidase and beta-N-acetylhexosaminidase led to the same AMC-OS, Man3GlcNAc2AMC. The final digestion product of AMC-OS (I) was GalGlcNAcMan3GlcNAc2AMC, suggesting a structural difference in one of the antennas of the minor sugar chain of asialofetuin. The monosaccharide quantitation and exoglycosidase sequencing were carried out at a 100 pmole level.