[Gastric erosions: pathogenesis, clinical features, diagnosis, and treatment].

Recent data on etiology, pathogenesis, diagnosis, and treatment of gastric erosion are reviewed. Classification of acute and chronic erosions is proposed. The authors point out to the lack of documented scientific information related to the role and significance of erosions in gastroduodenal pathology. Special emphasis is laid on risk factors, diagnosis, prevention, and treatment of gastropathies with reference to their clinical features and diagnostic criteria. The main provisions of the Maastricht Treaty 3 (2005) concerning NSAID gastropathies are outlined.

[Assessment of effectiveness of livolin forte in the treatment of patient with steatohepatitis]. / Otsenka éffektivnosti preparata livolin forte v lechenii bol'nykh steatogepatitom.

The article analyzes efficacy of the drug livolin in the treatment of patients with fatty hepatosis. It is shown that livolin promotes a rapid arresting of clinical symptomatology, normalization of biochemical indices, makes for improvement of physical-and-chemical properties of the bile.

[Use of enterol in the treatment of diseases complicated by diarrhea syndrome]. / Primenenie énterola pri lechenii zabolevanii, soprovozhdaiushchikhsia sindromom diarei.

The article analyses data on clinical efficacy of the drug enterol in patients with chronic pancreatitis and chronic atropic gastritis. The use of enterol in a complex therapy has been shown to favour quick dispelling of the pain and dyspeptic syndromes, normalization of stools, elimination of intestinal dysbacteriosis or alleviation of its gravity.

[A trial of the use of Maldroxal in treating patients with duodenal peptic ulcer]. / Opyt primeneniia maldroksala v lechenii bol'nykh iazvennoi bolezn'iu dvenadtsatiperstnoi kishki.

The foreign-made drug preparation maldroxal the formulation of which includes aluminium hydroxide, magnesia hydroxide and dimeticon, is an effective medicine making for the instant relief of pain and dyspeptic syndromes; it is capable of exerting an antiinflammatory effect. It has also been ascertained that maldroxal fails to influence much the elimination of H. p., which fact necessitates an additional prescription of antibacterial drugs.

[The effect of shigellae on delayed hypersensitivity in mice infected by different routes]. / Vliianie shigell na giperchuvstvitel'nost' zamedlennogo tipa u myshei pri raznykh sposobakh infitsirovaniia.

The influence of virulent and avirulent shigellae on delayed hypersensitivity in the case of infection by different methods has been examined. It was found that the stimulating effect of avirulent shigellae and suppressive effect of virulent shigellae were displayed after intranasal infection. Intraperitoneal and intravenous infection was accompanied by only immunosuppressive influence, which was displayed by the virulent bacteria. The discrimination of T-suppressors by low doses of cyclophosphamide did not abolish the suppressive effect of shigellae. At the same time immunosuppressive factor of spleen was produced equally after infection by different-virulence shigellae. A conclusion was drawn that T-suppressors and immunosuppressive spleen factor did not take part in the mechanism of shigellae immunosuppression.

[Interaction of rabbit skeletal muscle glycogen synthase I with substrate analogs--oxo-UDP hydrazones]. / Vzaimodeistvie glikogensintazy I skeletnykh myshts krolika s analogamisubstrata--gidrazonami okso-UDP.

Inhibition of rabbit skeletal muscle glycogen synthase I was studied by using several synthetic substrate analogs: dansylhydrazone of oxo-UDP, 3-hydroxy-2-naphthoylhydrazone of oxo-UDP, salicyloylhydrazone of oxo-UDP, 1-oxyl-2,2,5,5-tetramethylpyrrolidine-3-carbonylhydrazone of oxo-UDP, N'-(dansyl)hydrazinocarbonylhydrazone of oxo-UDP and N'-(fluorenylidene-9)-hydrazinocarbonylhydrazone of oxo-UDP. All these compounds (with the exception of the nitroxyl-containing hydrazone) were characterized by a nonlinear dependence of the reverse reaction rate on the analog concentration in Dixon coordinates. The parabolic type of inhibition was due to the fact that the analogs tested except for the nitroxyl-containing hydrazone were able to interact both with the active center of the enzyme and with the FMN-binding site. The inhibition constants for oxo-UDP hydrazones were calculated for the both centers; their comparison revealed that the affinity of the analogs for the FMN-binding site increased with an increase in the radical hydrophobicity. These data suggest that the site with a high binding affinity for FMN is hydrophobic in nature. Apparently, isoalloxasine-like compounds display the highest affinity for this site.

[Interaction of glycogen synthase from rabbit skeletal muscles with 1,5-gluconolactone]. / Vzaimodeistvie glikogensintazy skeletnykh myshts krolika s 1,5-gliukonolaktonom.

1.5-Gluconolactone was shown to inhibit in a competitive manner the activity of both I- and D-forms of rabbit skeletal muscle glycogen synthase. Unlike other known inhibitors (UDP and adenyl nucleotides) the affinity of the enzyme D-form for 1.5-gluconolactone is lower than that of the I-form. The joint inhibition of glycogen synthase by UDP and 1.5-gluconolactone is characterized by positive cooperativity. It was supposed that the binding of the nucleotide part of the substrate molecule is preceded by the UDPglucose glucosyl residue interaction with the enzyme and induces a closer resemblance to the transient state. The effect of the allosteric inhibitor, ADP, on the enzyme activity is conditioned by its effect on the conformational state of UDP-glucose glucosyl residue binding site. Phosphorylation of glycogen synthase results in conformational changes in the same active site region, although the pyrimidine base binding site also seems to be involved in this process.

[Inhibition of glycogen synthase I from rabbit skeletal muscles by 1,5-gluconolactone]. / Ingibirovanie glikogensintazy I skeletnykh myshts krolika 1,5-gliukonolaktonom.

The effect of 1.5-gluconolactone on the activity of rabbit skeletal muscle glycogen synthase I was investigated. Using statistic methods (pair regressive analysis) and computer analysis on a Robotron EC 1834 personal computer, it was found that 1.5-gluconolactone is a true competitive inhibitor of the enzyme in respect of UDP-glucose. Similar to UDP, 1.5-gluconolactone increases the Km value for UDP-glucose without affecting the V value. The Ki value for 1.5-gluconolactone is equal to 123 + 8 microM and it coincides with the Km value for UDP-glucose.

[Turbidimetric method of determination of glycogen synthase activity in rabbit skeletal muscles]. / Turbidimetricheskii metod opredeleniia aktivnosti glikogensintazy skeletnykh myshts krolika.

A turbidimetric procedure is described, which involves the monitoring of changes in glycogen turbidity at wavelengths above 300 nm and continuous recording of rabbit skeletal muscle synthase activity. The recalculation coefficients were found to be equal to 1.69 +/- 0.08 mM UDP per unit of optical density at 360 nm and to 2.03 +/- 0.01 mM UDP per unit of optical density at 400 nm. The procedure allows a kinetic analysis of the enzyme within a broad range of concentrations and under various conditions. The glycogen synthase activity did not depend on the buffer capacity when 10-100 mM Tris-HCL buffer, pN 7.8, was used. The rate of the enzymatic reaction was correlated with the enzyme concentration within the range of 5 to 50 micrograms/ml. The curve for glycogen synthase saturation with UDPG is described by the Michaelis-Menten equation, when either 0.04-0.08 mM glucose-6-phosphate for for the D-form were used in mixtures containing 5 mM MgCl2 for the D-form were used in mixtures containing 5 mM MgCl2 and 10 mM Na2SO4. The turbidimetric and spectrophotometric procedures yielded similar results.

[Substrate specificity of glycogen synthase from rabbit skeletal muscles]. / O substratnoi spetsifichnosti glikogensintazy skeletnykh myshts krolika.

Nitrous bases were shown to play an essential role in the specificity of active and adenyl nucleotide binding sites. Pyrimidine base determines the substrate specificity of rabbit skeletal muscle glycogen synthase; a crucial role in this process is ascribed to the lactam fragment of the pyrimidine cycle. The 2-oxo group was also shown to be involved in substrate binding. The adenyl nucleotide binding site interacts only with 6-aminopurine derivatives. A negative interaction was found between the enzyme active center and the adenyl nucleotide binding site.

[Interaction of glycogen synthase of rabbit skeletal muscles with flavin mononucleotide]. / Vzaimodeistvie glikogensintazy skeletnykh myshts krolika s flavinmononukleotidom.

The effect of flavin mononucleotide (FMN) on the activity of the I- and D-forms of rabbit skeletal muscle glycogen synthase has been studied for the first time. FMN has been shown to inhibit in a noncompetitive fashion the both forms of the enzyme, the D-form being more sensitive to the effect of the inhibitor. It has been shown also that glycogen synthase has three different sites involved in the interaction with inhibitors, namely, and active site, an adenyl nucleotide binding site and a FMN binding site. FMN binding has been shown to occur mostly via the isoalloxasine ring.

[Mechanism of the reaction catalyzed by glycogen synthetase I in rabbit skeletal muscle]. / K voprosu o mekhanizme reaktsii, kataliziruemoi glikogensintazoi I skeletnykh myshts krolika.

1.5-Gluconolactone was shown to exert a strong inhibiting effect on the activity of rabbit skeletal muscle glycogen synthase I. The Ki values determined according to Dixon (0.13 mM) and Chuang and Bell (0.14 mM) coincide with the Km value for UDPG. Within the pH range of 5.4-7.0, N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (less than or equal to 3 mM) specifically inhibits the carboxyl group, which was supported by the reactivation of the enzyme under mild alkaline conditions. The reversible competitive inhibitor of glycogen synthase and the UDP reaction product as well as 1.5-gluconolactone afford an effective protective effect. It is supposed that the reaction catalyzed by rabbit skeletal muscle glycogen synthase I results in the formation of an intermediate carbonium ion. An essential role in the enzyme activity belongs to the carboxylic group of the active center.

[Formation of the glycogen synthase I-glycogen complex]. / Izuchenie obrazovaniia kompleksa glikogensintazy I s glikogenom.

A glycogen-free glycogen synthase I was isolated from rabbit skeletal muscles as a tetramer. Using the light scattering technique, the formation of the glycogen synthase I--glycogen complex was investigated; the Kd value [(0.40 +/- 0.09) X 10(-7) M], the absorption capacity of glycogen towards the enzyme [aM = (1.89 +/- 0.4) X 10(-6) mol] and the number of enzyme-binding sites per polysaccharide molecule (n = 10) were determined, using rabbit liver glycogen (Mr = 5.28 X 10(6)). After the formation of the glycogen synthase I--glycogen complex has been completed, the reactivity of some SH-groups of the enzyme is reduced and some of them become masked towards 5,5'-dithiobis-2-nitrobenzoate.

[Covalent modification of glycogen synthase I in rabbit skeletal muscle by 5'-fluorosulfonylbenzoyl derivatives of uridine]. / Kovalentnaia modifikatsiia glikogensintazy I skeletnykh myshts krolika 5'-ftorsul'fonilbenzoil'nymi proizvodnymi uridina.

Preincubation of rabbit skeletal muscle glycogen synthase I with 5'(p-fluorosulfonylbenzoyl)uridine (p-FSBU) or 5'-(m-fluorosulfonylbenzoyl)uridine (m-FSBU) results in a decrease of the enzymatic activity with time. UDP, the product of the glycogen synthase reaction, protects the enzyme against inactivation. It was shown that the covalent binding of the enzyme with each of its inhibitors is preceded by the formation of a reversible complex with Ki = 0.285 and 1.820 mM for p-FSBU and m-FSBU, respectively. This reaction is of pseudo-first order with respect to the inhibitors. The K2 values for p-FSBU and m-FSBU are nearly identical, i. e. 0.050 and 0.042 min-1, respectively, which suggests modification of the same functional group of the enzyme. The number and reactivity of the SH-groups of glycogen synthase I were determined, using 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB). The total number of SH-groups determined in the presence of 8 M urea is six as calculated per enzyme monomer. In the native enzyme DTNB titrates two SH-groups which according to their reactivity can be subdivided into 2 groups. The more reactive SH-group is localized in the active center of the enzyme. p-FSBU induces covalent blocking or screening of this SH-group during specific interaction with the active site of glycogen synthase I.

[Characteristic properties of the complex of glycogen synthase with glycogen]. / Kharakteristika svoistv kompleksa glikogensintazy I s glikogenom.

The glycogen synthase I--glycogen complex isolated from rabbit skeletal muscles is stable during precipitation with trichloroacetic acid and Sepharose 2B chromatography. The complex catalyzes the synthesis (lengthening) of the alpha-1.4-glucosyl chains when endogenous or exogenous enzyme-free glycogen is used, the initial rates of this synthesis being identical. Preincubation with glycogen does not cause activation of the complex or formation of additional glycogen synthase I--polysaccharide bonds. The complex is characterized by saturation with respect to glycogen; the molar concentration ratios of the non-reducible chain and protein monomer within the complex does not exceed 100. An increase in the length of the synthesized alpha-1.4-glycosyl chains of glycogen results in a decrease of the rate of the glycogen synthase reaction in time.

[Potentiometric study of the progress of the glycogen synthetase reaction]. / Izuchenie khoda glikogensintetaznoi reaktsii vo vremeni potentsiometricheskim metodom.

A procedure for continuous recording of the glycogen synthetase 1 activity, based on the potentiometry, is described. The stoichiometric ratio of H+/UDP, estimated at pH 7.8 and 30 degrees, was equal to 0.89 +/- 0.01. The specific activity of the enzyme did not depend on the buffer capacity in the incubation mixture containing 0.8-10 mM Tris-HCl, pH 7.8. The course of reaction had a linear type at the enzyme concentration of 4-20 mcg/ml in presence of 10 mM MgCl2. The rate of glycogen synthetase reaction was decreased in the course of experiment if the activator was absent. MgCl2 was more suitable activator than Na2SO4, universally accepted for this form of the enzyme.

[Quaternary structure of glycogen synthetase I from rabbit skeletal muscles]. / Chetvertichnaia struktura glikogensintetazy I skeletnykh myshts krolika.

Glycogen synthetase I from rabbit skeletal muscles was studied by electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate. The presence of glycogen in the preparation prevented the destruction of the quaternary structure of the enzyme. In order to separate glycogen synthetase I from glycogen, alpha-amylase from saliva, pig pancrease and bacterial amyloglucosidase were used. The subunit composition of the total preparation and that of the individual glycogen synthetase forms separated ultracentrifugally in the sucrose density gradient, were shown to be identical. The molecular weight of the minimal subunit of glycogen synthetase I from rabbit skeletal muscles was shown to be 36,000. A comparison of the subunit composition of the enzyme preparations stored in the presence and in the absence of phenylmethylsulfanylfluoride did not show that the preparation possesses proteolytic activity.

[Characteristics of glycogen synthetase I from rabbit skeletal muscles]. / Osobennosti stroeniia glikogensintetazy 1 iz skeletnykh myshts krolika.

Electrophoretic heterogeneity of glycosynthetase I from rabbit skeletal muscles is observed. Multiple glycosynthetase forms are separated in sucrose density gradient, their molecular weights are estimated. The existence of the enzyme as an equilibrium system of oligomeric forms, capable of reversible association-dissociation, is demonstrated. Dissociating effect of ATP, high pH values (11--12) and high ionic strength (2 M KCl) on oligomers of glycogen synthetase I is found to take place. Different activity of oligomers of different association degree is observed.