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J Suttnar

Publications and source records attributed to J Suttnar.

At least 37 records · Page 2Linked to original sources
PubMed1994

Hb Nottingham or alpha 2 beta 2 98 (FG5) Val-->Gly in a Czech child.

We report a fourth case of Hb Nottingham [alpha 2 beta 2 98 (FG5) Val-->Gly] observed in an 8-year-old girl in the Czech Republic with clinical and laboratory symptoms of severe hemolytic anemia. The unstable hemoglobin probably represents a de novo mutation, since the parents of the patient and the two siblings do not exhibit any hematological abnormalities. Splenectomy had a beneficial effect on the degree of hemolysis, as well as on the Hb level.

Amino Acid Sequence↗
PubMed1992

[Fibrinogen seen as an independent cardiovascular factor from the molecular aspect].

The blood protein fibrinogen is one of the main independent cardiovascular risk factors and it is very likely that an increased fibrinogen level is not the consequence of cardiovascular disease but its direct cause. Fibrinogen participates actively in many processes in the organism and undergoes various changes of the molecule but it is not known what is the molecular background, why even a slight increase of the fibrinogen level is so dangerous as regards increased risk of cardiovascular attacks. In the present work the authors compared, using monoclonal antibodies, the rate of release of fibrinopeptides A and B (FpA, FpB) by the action of thrombin from fibrinogen in solution and from fibrinogen adsorbed to a solid surface. The authors revealed that the rate of FpB breakdown from sorbed fibrinogen, contrary to fibrinogen in solution is comparable to the release rate of FpA and does not depend on the release of FpA (except for competitive inhibition). The release of FpB from sorbed fibrinogen thus takes place, contrary to fibrinogen in solution, at a significant recordable rate from the very onset of thrombin action. Fibrinogen adsorption to a solid surface is associated with conformation changes which cause this effect and which lead to the formation of a two-dimensional formation formed by fibrinogen after its interaction with the surface of activated platelets.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular Diseases↗
PubMed1992

[New methods of isolating recombinant proteins].

Recombinant proteins are isolated from very complex protein mixtures present in the producing cell. The isolation process involves in general four mutually interconnected stages: 1. release of the recombinant protein from the cellular environment, 2. preparation of the specimen for separation, 3. separation, 4. qualitative and quantitative analysis of the preparation. Each of these stages is formed by a complex series of methods which destroy the cellular wall, solubilize the specimen and involve the use of suitable precipitation, chromatographic, electrophoretic, immunochemical and other techniques for separation and analysis. In the submitted paper the authors describe a relatively simple isolation of recombinant peptide used for the preparation of a diagnostic kit for AIDS. From knowledge of the sequence of nucleotides in cDNA antisense peptides can be derived which have a high affinity with the isolated protein and they can be also used for affinity chromatography. An effective isolation technique is the use of mimetic ligands on the basis of textile dyes. By their combination and possible modification it is also possible to achieve separation of the required protein from contaminating substances. The mentioned highly specific methods can be combined with classical chromatographic techniques. During every step individual chromatographic fractions are tested by SDS electrophoresis in polyacrylamide gel incl. possible use of immunoblotting a specific staining.

Escherichia coli↗
PubMed1991

Comparison of rat and human major platelet glycoproteins.

1. Using electrophoretic techniques combined with various detection methods we ascribed rat platelet glycoproteins (GPs) related to human GPIb, GPIIb and GPIIIa. 2. Rat GPIIb and GPIIIa crossreacted with rabbit polyclonal antibodies against human GPIIb and GPIIIa. 3. Species differences in glycosylation of GPs were shown using various lectins. 4. Molecular mass of rat major GPs was determined by SDS-PAGE (unreduced, reduced, kDa): GPIb (200, 166/26), GPIIb (140, 120/32) and GPIIIa (96, 106). 5. Isoelectric points of rat GPIIb and GPIIIa are shifted to the alkaline region as compared to human related GPs.

Animals↗
PubMed1990

[Monoclonal antibodies against fibrinogen and fibrin and against their proteolytic degradation products].

The level of fibrinogen (FDP) and fibrin (fDP) degradation products is one of the surprisingly few unequivocal indicators of the activity of the coagulation and fibrino (geno) lytic system. Today it is beyond doubt that, similarly as the FDP/fDP level is of unequivocal importance, traditional methods of their assessment are very equivocal. Fibrin and FDP/fDP are molecules derived from fibrinogen, which are formed from the latter as a result of a series of reactions during which structures are formed or are made available which are not present in the fibrinogen molecule. New antigenic determinants are formed, in relation to the original molecule so-called neoepitopes, neoantigens. The great predominance of monoclonal antibodies prepared in the meantime reacts with fibrinogen as well as with fibrin and their degradation products. By means of specific approaches and original methods it proved, however, possible to prepare some specific monoclonal antibodies which were successfully used in diagnostic tests in vitro; their use for detection of thrombi in vivo is tested as well as their use for an increasingly effective thrombolytic therapy after their conjugation with plasminogen activators. It may be expected that this problem will be intensely developed in the near future.

Antibodies, Monoclonal↗
PubMed1990

The action of a fibrin-promoting enzyme from the venom of Agkistrodon contortrix contortrix on rat fibrinogen and plasma.

The action of a fibrin-promoting enzyme isolated from the venom of A.c.contortrix was investigated. The ratio of fibrinopeptides A and B released was similar in isolated human and rat fibrinogen and human plasma, fibrinopeptide B always being released preferentially. However, no clotting occurred in rat plasma, and no fibrinopeptides were released even after prolonged incubation. The results suggest strong, fast-acting irreversible neutralization of the enzyme activity in rat plasma.

Animals↗
PubMed1990

[Glanzmann thrombasthenia--a defect in the surface membrane of platelets].

The authors present a clinical description, detailed platelet function analysis, and certain biochemical parameters in two siblings with Glanzmann thrombasthenia (G. t.). The isolated occurrence of this disorder in the family corresponds with its autosomal recessive inheritance. In both cases blood platelets completely failed to aggregate. In contrast, the platelet interaction with ristocetin, reflecting their ability to adhere to the subendothelium, the so-called "shape change", the storage granule contents and their release and arachidonic acid metabolism were unaffected. Further, the aggregation abnormality was accompanied by marked procoagulant activity and clot retraction defects; these functions, similarly as aggregation, are implemented on the platelet surface. The analysis of blood platelet proteins, using two dimensional polyacrylamide electrophoresis, confirmed the absence of glycoprotein GP IIb and IIIa and a decrease of the fibrinogen content. The analysis of these findings in G. t. led to the contemporary concept that GP IIb and IIIa on the platelet surface act as receptors for platelet aggregation.

Adult↗
PubMed1990

Stroma-free hemoglobin solutions purified by chloroform and pasteurization.

Several approaches to the processing of native stroma-free hemoglobin solutions (SFH) were reconsidered regarding present requirements for SFH production and quality. Treatment of outdated red blood cells (RBCs) with chloroform and/or by pasteurization were evaluated for technical ease, speed and efficacy in removing stromata, phospholipids and non-heme proteins from RBC hemolysates. The influence of both procedures upon spontaneous hemiglobin formation in stored, preferably freeze-dried SFH was compared. Among other analytical methods, sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS PAGE) and isoelectrofocusing were used for mutual comparison of the purification procedures. Pasteurized samples were significantly better purified, more homogeneous but also more susceptible to spontaneous oxidation, probably due to heat inactivation of enzymic scavengers of oxygen radicals. On the other hand, the chloroform-treated, unheated SFH samples were less purified from non-heme proteins, but were more stable. Fructose and sucrose were equally active in protecting SFH from oxidation during freeze-drying. At present, the easy chloroform treatment and freeze-drying of thus purified SFH with fructose of sucrose seems to offer a plausible technological compromise which merits further investigation.

Chloroform↗
PubMed1990

Red blood cells under mechanical stress.

The effect of mechanical stress on erythrocytes suspended in various media was studied. The ability of the cells to increase their glucose consumption was found to be the major criterion allowing to divide the media into two groups. In plasma, serum or in Ringer's solution supplemented with albumin and glucose the energy consumption by mechanically stressed erythrocytes increased 20 to 50%; no morphological changes of the cells were observed either in suspension or on Giemsa smears. The cells behaved in the same way in Mg2(+)-free medium. The other group included protein-free medium (Ringer's solution supplemented with glucose) and Ca2(+)-free Ringer's solution supplemented with albumin and glucose; under these conditions erythrocytes were unable to raise their energy consumption in response to mechanical stress, and after some period structural impairment of the membrane could be observed on Giemsa smears. No differences in metabolism-associated nucleotide concentrations (ATP, ADP, NAD, NADP) were observed between the samples. Resealed red cell ghosts with high concentrations of intracellular components were prepared as a model of cells with damaged membrane. In these ghosts (with low ATP concentration) mechanical stress produced increased proportions of echinocytes, even in the "native" suspension. These results have confirmed the vital role of the energy-consuming contractile apparatus in the erythrocyte membrane, and supplied a clue to the role of Ca2+ in its activation and to the influence of extracellular proteins on the maintenance of in red cell shape.

Calcium↗
PubMed1989

Distortion of the electrophoretic titration curves of some proteins.

The electrophoretic titration curves of complex mixtures of vitamin K-dependent human blood proteins and proteins of Bothrops asper venom were investigated. In both protein mixtures some curves exhibited marked distortions such as additional maxima and minima when Pharmalyte 3-10 carrier ampholytes were used for isoelectric focusing in agarose gels. The distortions result from an unspecific interactions between some carrier ampholyte constituents with particular proteins. The interacting carrier ampholyte components could be completely removed by binding to albumin and ultrafiltration through a UM-2 Amicon membrane with resultant regular titration curves. The interacting carrier ampholyte species were only partially removed by ultrafiltration through a UM-2 membrane without incubation with albumin.

Animals↗
PubMed1989

Fibrinopeptide-releasing enzymes in the venom from the southern copperhead snake (Agkistrodon contortrix contortrix).

Protein fractionation techniques utilizing the different properties of the sample (size, charge, sugar moiety) were employed to characterize the crude A. c. contortrix venom. Gel filtration chromatography resolved about six to eight peaks, high performance liquid ion exchange chromatography and chromatofocusing about 12-14 peaks exhibiting hydrolytic activity. Two fibrin clot-promoting enzymes--both releasing fibrinopeptides A and fibrinopeptides B, but with different fibrinopeptide A/fibrinopeptide B relative rates were observed. The two enzymes (or enzyme isoforms) were serine proteinases with essentially the same hydrolytic activity towards low molecular chromogenic substrate for thrombin. They were of approximately the same size (one peak of 68,000 relative mol.wt on gel filtration chromatography), had apparent isoelectric points of about 6.4 and 5.4, respectively, and were glycoproteins.

Chromatography, Gel↗
PubMed1989

[The effect of blood platelet freezing on their antigen activity].

The authors investigated the effect of freezing of platelets after addition of various cryoprotective substances (glycerol, dimethyl sulphoxide and hydroxyethyl starch) on the preservation of some antigenic properties of these blood cells. It was revealed that during freezing of platelets in 5% glycerol and 4% hydroxyethyl starch no change of the specific antigen Kob and of HLA antigens occurred. Freezing in dimethylsulphoxide, however, weakened the activity of some antigens; usually this applied to antigen Kob, in HLA antigens it was rather an exception. From the results ensues, however, that in the transfusion practice it is important to foresee even in transfusions of cryopreserved platelets possible alloimmunization.

Antigens, Differentiation↗
PubMed1988

Evaluation of individual variability in the composition of Agkistrodon contortrix contortrix venom by means of HPLC and two-dimensional PAGE.

Qualitative and quantitative differences of coagulant enzymes in venom samples from individuals of the Agkistrodon c.c. were studied by means of 2D-PAGE and high performance anion-exchange chromatography. A great diversity was found among individual venoms. The two most similar venoms had an identical composition in only about 90%, the least similar ones in about 45% spots. All venoms studied contained more than two fractions with fibrinolytic activity. In three out of the nine analysed venoms two different thrombic proteases were present, one venom contained only one of these enzymes, whereas in five venoms no thrombic activity was detectable.

Animals↗
PubMed1988

Assessment of a complex mixture of interacting proteins in the coagulant active venom from Agkistrodon contortrix contortrix.

The crude venom of Agkistrodon contortrix contortrix was characterized by means of 2D-PAGE (using various separation principles in the respective directions) and high performance gel filtration chromatography. It was found that the venom presents a rich and remarkably stable mixture of proteins, mostly glycoproteins, which may interact each other. High stability of the venom in spite of the presence of many proteolytic enzymes, must most likely be attributed to the sugar moieties of venom proteins. Carbohydrate composition also causes considerable heterogeneity in charge and the presence of wide range of charge isomers. The intricate complexity of the venom makes it a real difficult-to-separate mixture.

Animals↗