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Biomedical subjects

L Hartmann

Publications and source records attributed to L Hartmann.

At least 37 records · Page 2Linked to original sources

Insulin dependence of M2 pyruvate kinase in primary culture of human liver.

In the basal state, the presence of L pyruvate kinase (LPK) was constantly observed in primary human liver cell cultures initiated from explants, when cells were examined by immunofluorescence and double labelling. After short-term insulin incubation, M pyruvate kinase (MPK) appeared. Therefore, both LPK and MPK were located in the same cells. We previously obtained the same results in isolated rat hepatocytes in which we demonstrated that short-term regulation of M2PK by insulin was a function of dose and/or incubation time. The present work established that similar conditions govern the regulation of this isozyme in vitro in human hepatocytes.

Cells, Cultured

[Molecular interaction between synthetic spirobutenolides and C1 esterase normal inhibitor].

Previously we have found that spirobutenolide synthetic derivatives show an inhibiting effect on C1 esterase activity. In contrast to these compounds some derivatives in the same series reveal an esterase activity when they are added to a C1 esterase preparation in presence of normal serum. The present work shows that this effect reflect an interaction with natural inhibitor C1 INH.

Complement C1 Inactivator Proteins

[Radioimmunologic and chromatographic correlations of urine and blood Tamm-Horsfall glycoproteins].

A comparative analysis of urine and serum THG is carried out using physico-chemical and radioimmunological methods. It demonstrates a real similarity in the antigenicity, the glycan structure and the polymerization-depolymerization. The presence of THG in various biological fluids and tissues is an extra argument in favor of such an identity. A multifocal synthesis of THG and not an exclusively renal one is admitted. Such a conception seems to be more consistent with the membrane function of THG towards some ions in various tissues.

Chromatography, Affinity

[Role of serum and urinary Tamm-Horsfall protein in the surveillance of kidney transplants].

The study of 24-h urinary excretion proves to be quite interesting from a theoretical point of view on account of its topographic origin in the nephron and from a practical point of view to control renal transplant patients with favourable or unfavourable course. In both cases, the results we obtain are in accordance with that of blood creatinine assay and ratio N-acetyl-beta-D-glucosaminidase (NAG)/creatinine in urine. The prolonged study of serum THG concentration confirms the previous data regarding the outcome of renal grafts. Moreover, particularly low concentration rates probably imply the interference of factors such as: renal toxins or anti-THG autoantibodies.

Acetylglucosaminidase

[Determination of serum creatinine by gas-liquid chromatography].

The gas-liquid chromatographic measurement of serum creatinine is described in the present study. A preliminary concentration on cation exchange resin is used. The different steps of the operating procedure are analysed. A statistical comparison is undertaken between the results obtained with gas-liquid chromatography and kinetic colorimetry method using Jaffé assay.

Chromatography, Gas

C3, BF and C4 polymorphisms in familial Mediterranean fever.

BF, C3 and C4 phenotyping were investigated in 34 patients with familial Mediterranean fever (FMF) and in 48 control subjects. Both groups included Sephardic Jews born in Tunisia, Algeria and Morocco. No linkage between BF, C3 and C4 polymorphisms and FMF was found.

Alleles

[Primary structure of the glycan chains of normal C 1 esterase inhibitor (C 1-INH) after NMR analysis at 400 MHz].

The primary structural analysis of O- and N-linked carbohydrate chains of the C-1-esterase inhibitor purified from normal serum was carried out by 400-MHz 1H-NMR spectroscopy. C-1-esterase inhibitor protein of a molecular weight of 116,000 daltons contains 24 O-glycans: NeuAc (alpha 2-3) Gal (beta 1-3) GalNAc, 4 N-glycans: NeuAc (alpha 2-6) Gal (beta 1-4) (GlcNAc (beta 1-2) Man (alpha 1-3) [NeuAc (alpha 2-6) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-6)] Man (beta 1-4) GlcNAc (beta 1-4) GlcNAc and 2 N-glycans: NeuAc (alpha 2-3) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-3) [NeuAc (alpha 2-3) Gal (beta 1-4) GlcNAc (beta 1-2) Man (alpha 1-6)] Man (beta 1-4) GlcNAc (beta 1-4) GlcNAc. 30% of the N-glycans are fucosylated.

Carbohydrate Conformation

Structural basis of the heterogeneity of asparagine-linked oligosaccharides of a Waldenstrom's macroglobulinemia immunoglobulin M.

The extent of glycans heterogeneity in a pathological human immunoglobulin M ZAJ has been studied on oligosaccharides released by hydrazinolysis from the purified glycoprotein. After reduction with NaB3H4, asparagine-linked carbohydrate chains were separated by affinity chromatography on concanavalin A-Sepharose into oligomannosidic and N-acetyllactosaminic types. Glycans of the oligomannosidic type were further fractionated by HPLC and those of the N-acetyllactosamine type by preparative high-voltage electrophoresis. The primary structure of the main oligosaccharides was investigated on the basis of micro-methylation analysis, mass spectrometry and sequential exo-glycosidase digestion. Glycans of the oligomannosidic type varied in size from Man5GlcNAc2 to Man9GlcNAc2. N-Acetyllactosaminic glycans were found of the biantennary, bisected-biantennary and triantennary types. They presented a higher degree of heterogeneity due to the presence of a variable number of NeuAc and fucose residues. The new structures we report here were in addition to the major biantennary one we previously described on the basis of methylation analysis and 500 MHz 1H-NMR spectroscopy (Cahour, A., Debeire, P., Hartmann, L., Montreuil, J., Van Halbeek, H. and Vliegenthart, J.F.G. (1984) FEBS Lett. 170, 343-349): NeuAc(alpha 2-6)Gal(beta 1-4)GlcNAc(beta 1-2)Man(alpha 1-3)[Gal(beta 1-4)Glc-NAc(beta 1-2)Man(alpha 1-6)]Man(beta 1-4)]Glc-NAc(beta 1-4) [Fuc(alpha 1-6)]GlcNAc.

Asparagine

Primary structure of the major glycans of the N-acetyllactosamine type derived from the human immunoglobulins M from two patients with Waldenström's macroglobulinemia.

The carbohydrate chains of the pathological human immunoglobulins M from two patients with Waldenström's macroglobulinemia were released by hydrazinolysis. The N-acetyllactosamine-type glycans were obtained by affinity chromatography on concanavalin A and fractionated by high-voltage paper electrophoresis. The primary structure of the major compounds was elucidated on the basis of carbohydrate analysis, methylation analysis, including mass-spectrometry, and 500 MHz 1H-NMR spectroscopy. For both patients, this appeared to be a monosialyl monofucosyl biantennary structure; the compounds differed by the presence of an intersecting N-acetylglucosamine residue.

Amino Sugars

Tamm-Horsfall protein, a kidney marker is expressed on brain sulfogalactosylceramide-positive astroglial structures.

The Tamm-Horsfall (TH) glycoprotein and the acidic glycosphingolipid sulfogalactosylceramide (SGC) have a strictly superimposable localization on kidney tissue sections. The fact that SGC is a prevalent glycolipid in mammalian brain, prompted us to look for the presence of TH in the rat central nervous system (CNS). An antiserum raised against human TH was found to react with rat CNS homogenate in the complement fixation assay. This anti-TH antiserum recognized a rat CNS protein having an identical electrophoretical mobility on SDS polyacrylamide gel electrophoresis (PAGE). Indirect immunofluorescence on rat brain tissue sections allowed us to localize this brain TH cross-reacting material to ependymal cells and astrocytic processes such as the Bergmann fibers or astrocytic feet in contact with either the blood vessels or the meninges. All these astroglial structures are also SGC-positive. Since TH and SGC in the kidney are localized on a membrane that possesses an electrogenic Cl-pump, we propose that the astroglial structures which contain these two molecules are also the site of a Cl-transport system.

Animals

Presence of a Tamm-Horsfall-like glycoprotein in the CSF of neurology patients. First results.

A protein antigenically similar to Tamm-Horsfall glycoprotein ( THLG ) was determined in CSF by affinity chromatography followed by a radioimmunological assay. THLG seems not to be a constituent of normal CSF or an autoantigen. It probably originates from nervous tissue and not from plasma proteins. Its mean is higher in the CSF of multiple sclerosis patients than in the CSF of degenerative disorders patients. THLG seems to be a chemical component of neuronal membrane and its physiological functions remain unknown.

Blood-Brain Barrier

[Hereditary angioneurotic edema: a molecular disease caused by a defect in the O-glycosylation of C1 esterase inhibitor (C1-INH)].

A quantitative and qualitative study of neutral and aminosaccharides in C 1-esterase inhibitor (C 1-INH), protein of the complement system, was performed. We observe a mixed glycosylation of the molecule with an N-glycosylated: O-glycosylated chain ratio of 1: 4. The loss of the inhibitory activity of the molecule in hereditary angioedema (O ANH) is associated with an O-glycosylation deficiency which differs according to the two molecular variants: C 1-INH (1 A) and C 1-INH (II) previously described.

Angioedema

Inflammatory reaction in familial Mediterranean fever (FMF) before and with colchicine therapy.

The familial mediterranean fever (FMF) is an inherited, autosomal, recessive disorder which occurs predominantly but not exclusively in Sephardic Jews. It is characterized by a total increase of blood complement components, particularly C4, without any molecular anomaly and associated with an increase in other inflammatory proteins. With colchicine therapy, the symptomatology observed regresses or diminishes and onset of amyloidosis is prevented but the inflammatory and biochemical syndrome persists.

Adult