PubMed Health⌕ Search

Biomedical subjects

M Cuperlović

Publications and source records attributed to M Cuperlović.

18 recordsLinked to original sources
PubMed1998

Galectin-1 and -3 in cells of the first trimester placental bed.

The beta-galactoside-binding proteins galectin-1 and -3 are thought to modulate cell-extracellular matrix interactions in cell adhesion and migration. In this study, their occurrence in human trophoblast has been investigated. In the first trimester placenta galectin-1 is expressed in the cytotrophoblast of the mid and distal cell columns, but absent from the villous and proximal column cytotrophoblast. The villous syncytiotrophoblast was also positive. Galectin-3, on the other hand, was uniformly localized in the villous cytotrophoblast and mid and distal cell columns. Immunolocalization of these proteins in placental bed tissue has shown that galectin-1 and -3 are not present in cytokeratin-positive interstitially migrating cytotrophoblast. The co-localization of galectin-1 with extracellular laminin in cultures of cytotrophoblast, choriocarcinoma or decidual stromal cells is consistent with a role in the organization of extracellular matrix and the regulation of cell motility.

Antigens, Differentiation↗
PubMed1996

Cross-correlation effects on NMR lineshapes and peptide conformation.

Information about molecular structure and dynamics can potentially be obtained by studying dipole-dipole and chemical-shift anisotropy (CSA) auto-correlation and dipole-CSA cross-correlation effects in high-resolution NMR spectra. Equations for the lineshapes of the HN multiplet in the fragment- 15NH-CH- as a function of NH-CH dihedral angle are derived by including these effects within the framework of the Redfield treatment of relaxation. To test the utility of the theoretical results, 1H[15N] HSQC proton lineshape data for a variant of the enzyme staphylococcal nuclease in which all valine residues are labeled with 15N have been analyzed to obtain the conformational angle (phi) between the N-H and adjacent C-H bonds. The results are generally in good agreement with values of phi obtained from crystal structure data. Considerations in the further development of the analysis of the lineshape of the HN multiplet for experimental determinations of phi are discussed.

Algorithms↗
PubMed1993

Lectin binding as a biological test in vitro for the prediction of functional activity of human spermatozoa.

Adequate acrosome reaction is one of the essential events that has to occur in successful mammalian fertilization. The purpose of the present study was to assess the acrosome reaction in human spermatozoa by means of iodine-labelled lectins concanavalin A and peanut agglutinin ([125I]Con A and [125I]PNA). Six sperm samples in the control (fertile) group were compared with 24 samples obtained from infertile patients. The acrosome reaction in both groups was induced in vitro by adding follicular fluid. Iodine-labelled lectins were bound to the sperm surface, and alteration in the binding capacity for [125I]PNA and [125I]Con A after induced acrosomal reaction was the main parameter for the prediction of acrosome reaction and fertilizing ability. It is hoped that with the availability of this test, in-vivo data may be accumulated.

Acrosome↗
PubMed1992

[Membrane binding and soluble lectins in higher organisms].

Lectins defined as proteins other than enzymes and antibodies that possess binding sites for specific carbohydrate sequences, are associated with the cell surface, the cytoplasm, the nucleus, extracellular matrices and body fluids, and are involved in molecular recognition, trafficking of glycoproteins and tissue organisation. Animal lectins are classified into two main groups: the C-type and the S-type lectins, characterised by sequence homology, solubility, sugar specificity, distribution, developmental regulation, calcium-dependency and reducing agents-dependency for their saccharide binding activity. Under SANU Projects supervised by Academician Milovan Jovanović, lectin types C and S were investigated. Special emphasis was placed on asialoglycoprotein receptor of rat hepatocytes, soluble beta-galactoside-binding protein of human placenta and hepatic nuclear lectins. The results of this work are presented and discussed hereinafter.

Animals↗
PubMed1990

Serum alpha-fetoprotein levels and microheterogeneity in patients with different liver diseases.

Serum alpha-fetoprotein levels were determined in patients (268) with liver disease. Markedly elevated concentrations (greater than 100 micrograms/l) were found in twelve patients with malignant tumours and two with cirrhosis. Molecular variants of alpha-fetoprotein were distinguished by lectin affinity chromatography of these sera. Reversible binding to concanavalin A (86 +/- 5%) and to lentil agglutinin (61 +/- 19%) conformed to expected values for primary hepatocellular carcinoma except in one patient with a metastatic carcinoma whose alpha-fetoprotein binding to concanavalin A was similar to non-liver alpha-fetoprotein (44 +/- 13%), and the two patients with cirrhosis in whom binding to lentil agglutinin was typical for benign liver disorders (less than 20%). Since low levels of serum alpha-fetoprotein and non-characteristic alpha-fetoprotein binding patterns assisted in the regrouping of eleven out of 24 patients initially thought to have primary hepatocellular carcinoma, it was concluded that alpha-fetoprotein determination and lectin affinity chromatography are helpful in distinguishing primary hepatocellular carcinoma from metastatic and benign liver diseases. Slight increases in the alpha-fetoprotein level in the presence of serum hepatitis B surface antigen indicated seven patients at risk for primary hepatocellular carcinoma who should be monitored frequently.

Carcinoma, Hepatocellular↗
PubMed1990

Salt-soluble lectins of corn grain.

Lectins extracted from corn (Zea mays L.) kernel with Tris-HCl buffer pH 7.5 were isolated from the crude extract by affinity chromatography on Sepharose 6B-N-acetyl-d-galactosamine and Sepharose 6B-methylalpha-d-mannoside, and also by lectin affinity chromatography using concanavalin A and Lens culinaris lectin as ligands. According to preferential monosaccharide specificity, salt-soluble lectins of corn seed comprise at least two distinct types: N-acetyl-d-galactosamine-interactive and mannose-interactive lectins. The extracted lectins are unstable, with a tendency to form aggregates during storage.

Journal Article↗
PubMed1987

A D-mannose-specific lectin from Gerardia savaglia that inhibits nucleocytoplasmic transport of mRNA.

A new lectin has been isolated from the coral Gerardia savaglia by affinity chromatography, using locust gum as an absorbent, and D-mannose as eluant. Final purification was achieved by Bio-Gel P300 gel filtration. The agglutinin is a protein composed of two polypeptide chains with a Mr of 14800; the two subunits are not linked by disulfide bond(s). The isoelectric point is 4.8, the amino acid composition is rich in the acidic amino acids aspartic acid and glutamic acid. The absorption maximum for the protein was at 276 nm; with a molar absorption coefficient of 1.27 X 10(5) M-1 cm-1. The lectin precipitated erythrocytes from humans (A, B and O), sheep, rabbit and carp with a titer between 2(5) and 10(10); the affinity constant for lectin binding to sheep red blood cells was 2.8 X 10(8) M-1 and the number of binding sites, 3.2 X 10(5)/cell. Ca2+ ions are required for full activity; the pH optimum lies in the range between 6 and 11. Inhibition experiments revealed that the lectin is specific for D-mannose. The lectin is mitogenic only for those spleen lymphocytes from mice which had been activated by lipopolysaccharide. An interesting feature of this lectin is its ability to bind to glycoproteins present in nuclei from CV-1 monkey kidney cells. The fluorescein-isothiocyanate-labelled lectin reacted with six polypeptides in the nuclear envelope from rat liver (Mr 190,000, 115,000, 80,000, 62,000, 56,000 and 42,000) and with two polypeptides in the nuclear matrix or pore complex lamina fraction (Mr 190,000 and 62,000). The lectin inhibited the nuclear envelope mRNA translocation system in vitro. It is suggested that this effect is due to an interaction of the lectin with the nuclear glycoproteins gp190 and/or gp62.

Amino Acids↗
PubMed1987

Macro- and microelements in the cataractous eye lens.

This investigation included the determination of Na, K, Ca, Mg and Zn in lens and aqueous humor of cataract patients. Along with the development of senile cataract the Na concentration increased, while the K concentration diminished. In the cataractous eye lenses the concentration of Ca and Zn were higher than in normal transparent lenses. The concentrations of the investigated elements, except for Zn, were higher in lenses than in aqueous humor of the same patients. The concentration of Na and Zn in aqueous humor decreased as compared to the values for normal healthy persons. The Ca and K concentrations in aqueous humor were similar to the values for healthy persons. Investigations of electrolyte composition of the lens would be valuable for understanding the genesis and developmental mechanism of senile cataract.

Calcium↗
PubMedDate not supplied

[Study of an immunochemical test for early pregnancy detection].

The accuracy and reliability of the immunochemical tube test Gravinep for the early pregnancy detection were determined in comparison with another immunochemical test (Pregnosticon All-in) and with clinical data. The urine samples of 88 women were analysed. In 98.9% cases the result obtained with the Gravinep test was clinically confirmed and in 96.6% cases both immunochemical tests gave the same result. In a number of cases (6.8% with Gravinep and 5.7% with Pregnosticon) the result of the immunochemical reaction was doubtful, although it indicated the condition suggested by clinical examination.

Chorionic Gonadotropin↗