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C Hurel

Publications and source records attributed to C Hurel.

At least 19 recordsLinked to original sources
PubMed1998

Overexpression of the neuron-specific molecule BM88 in mouse neuroblastoma cells: altered responsiveness to growth factors.

Previous studies have shown that the BM88 antigen, a novel neuron-specific molecule, promotes the differentiation of mouse neuroblastoma (Neuro 2a) cells. In particular, stably transfected, with the BM88 cDNA, Neuro 2a cells overexpressing the BM88 antigen (Neuro2a-BM88 cells) are morphologically distinct from the nontransfected Neuro 2a cells; they exhibit enhanced process outgrowth and a slower rate of division. In this study we used Neuro2a and the morphologically differentiated Neuro 2a-BM88 cells to compare their responsiveness to growth factors. The growth factors we used were nerve growth factor (NGF), basic-fibroblast growth factor (b-FGF), and glial cell-line derived neurotrophic factor (GDNF). In addition, we used glial conditioned medium derived from either newborn mouse cerebral cortex (NBCC) or aged mouse cerebral hemispheres (MACH), as a source of normal glial factors. Because these cells express the cholinergic phenotype, we used choline acetyltransferase (ChAT) activity as a biochemical marker for comparison. A differential responsiveness to these factors was observed between Neuro 2a and Neuro 2a-BM88. The presence of NGF, 25 ng/ml, in the culture medium did not affect ChAT activity in either cell type. In contrast to NGF, in the presence of b-FGF, 5 ng/ml, the transfected cells, Neuro 2a-BM88, responded with a marked increase in ChAT activity. On the other hand, with GDNF, 1 ng/ml, only Neuro 2a cells showed an increase in ChAT activity. Finally, we found no response to the glial conditioned media, although these media contain several growth factors, including b-FGF. In conclusion, our findings show that overexpression of the neuron-specific antigen BM88 in neuroblastoma cells modifies their properties with respect to growth factor sensitivity, and, hence, the Neuro 2a and Neuro 2a-BM88 are suitable cell models to examine the role of growth factors in neuronal differentiation.

Animals↗
PubMed1995

The BM88 antigen, a novel neuron-specific molecule, enhances the differentiation of mouse neuroblastoma cells.

The BM88 antigen is a neuron-specific molecule widely distributed in the mammalian nervous system. It is a 22-kDa, apparently not glycosylated, integral membrane protein, which appears early during brain development and remains at high levels in the mature animal. Here, we describe the cDNA cloning of the porcine BM88 antigen and present evidence that this protein is involved in neuroblastoma cell differentiation. The deduced protein is a novel molecule consisting of 140 amino acids and bears a putative transmembrane domain at the COOH-terminal region. The mRNA of this protein is expressed only in neural tissues, where it is restricted to neurons. Stably transfected Neuro-2a cells overexpressing the BM88 antigen exhibited a significant change in morphology, reflected by enhanced process outgrowth, and a slower rate of division. Moreover, in the presence of differentiation agents, such as sucrose and retinoic acid, an accelerated differentiation of the transfected Neuro-2a cells was observed. Especially in the presence of sucrose, the consequent overexpression of the BM88 antigen in the transfected cells resulted in their enhanced morphological differentiation accompanied by the induction of neurofilament protein expression. Our results suggest that the BM88 antigen plays a role in the differentiation of neuroblastoma cells.

Amino Acid Sequence↗
PubMed1991

Purification and characterization of neuron-specific surface antigen defined by monoclonal antibody BM88.

Monoclonal antibody BM88 recognizes a neurospecific surface antigen in the CNS and the PNS. In the present study, the antigen recognized by BM88 was immunopurified from pig brain and shown to be a 22-kDa polypeptide by reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Under nonreducing conditions a protein of 40 kDa was obtained, a result indicating that the antigen is composed of two polypeptide chains of equal molecular weight linked by disulfide bridges. Gel filtration of the purified antigen in the presence of Emulphogene suggested that it may be either a monomeric or a dimeric protein. However, in the presence of Triton X-100 a monomeric structure was implied. N-Glycanase digestion indicated that the protein is probably not glycosylated. The purified antigen was characterized as an integral membrane protein by hydrophobic chromatography and phase-separation experiments with Triton X-114. The antigen, or at least the antibody binding region of the molecule, is very susceptible to protease attack, as judged by protease digestion experiments on brain membranes. By using very low concentrations of papain combined with short incubation times, the antigen was converted to a 16.3-kDa membrane-associated polypeptide as assessed by immunoblotting. This polypeptide contained the BM88 binding epitope. Soluble BM88 immunoreactive polypeptides were not obtained. Bacillus cereus phospholipase C was also unable to solubilize the antigen from the membrane. Our results suggest that the molecule, possessing at least one small extramembranous domain, is attached to the membrane via a polypeptide chain.

Animals↗
PubMed1989

Neuron- and myelin-specific monoclonal antibodies recognizing cell-surface antigens of the central and peripheral nervous system.

Immunohistochemical screening of monoclonal antibodies raised against Triton X-114-treated synaptic membranes revealed two monoclonal antibodies, namely BM88 and BM72, with characteristic binding specificities in the central and peripheral nervous systems of the pig. Monoclonal antibody BM88 was exclusively associated with neuronal elements while BM72 was myelin-specific. Thus, in the central nervous system, immunostaining with BM88 was observed throughout the gray matter of all regions of the forebrain and spinal cord tested. In the peripheral nervous system, BM88 strongly labelled the perikarya and processes of dorsal root ganglion neurons as well as the myelinated and unmyelinated neuronal processes of the dorsal roots; BM88 immunoreactivity was also detected in neuronal cell bodies and fibres of the enteric ganglia. In addition, BM88 immunolabelled the cell-surface of cultured neurons derived from brain. In mixed cultures the staining was uniformly distributed on the perikarya and along the neurites of these cells. However, in neuron-enriched cultures where 95% of the cells were immunochemically identified as neurons, the staining of the neuronal surface membrane was patchy. This phenomenon was independent of days in culture and suggested that the distribution of the BM88 antigen on the cell surface of neurons may be regulated by neuron glia interactions. By Western blotting, the antigen recognized by BM88 in brain membrane fractions which had undergone reducing sodium dodecyl sulphate/polyacrylamide gel electrophoresis was shown to be a 22,000 mol. wt polypeptide. When extracted with Triton X-114 this polypeptide partitioned into the detergent-rich phase, a property typical of an amphipathic membrane protein. In non-reducing conditions BM88 bound to a band with a molecular weight of 43,000. These results show that the BM88 antigen is composed of two polypeptide chains of equal molecular weight linked by disulphide bridges. Monoclonal antibody BM72 recognized a myelin-associated antigen in the central and peripheral nervous system. Immunohistochemical evidence suggested a cell-surface location for this antigen. By solid phase radioimmunoassay, monoclonal antibody BM88 was shown to cross-react with brain membrane fractions from pig, rabbit and rat while BM72 recognized only a pig membrane antigen. Both monoclonal antibodies BM88 and BM72 may be used as specific cellular markers in the nervous system.

Animals↗
PubMed1989

[Performance of Pall filters (RC 100 and PL 100) for the removal of leukocytes from red-cell concentrates and platelets].

20 red cell concentrates (buffy-coat not removed), 5 pools of 5 and 5 pools of 10 standards plateles concentrates, as well as 5 single donor platelet concentrates obtained through Haemonetics V50-1 cytoplasmapheresis procedure, were filtered, within 48 hours after donation, using RC 100 and PL 100 blood filters developed by Pall Company. Using the RC 100 filter on red cell concentrates, the rate of leukocyte removal exceeded 99% of the initial values. The residual leukocyte count per unit was 5.8 +/- 3.4 10(6). Leukocytes in red cell concentrates filtered after a previous one on the same filter numbered 18.6 +/- 8.9 10(6). The rate of platelet removal exceeded 97% of the initial amount. Red cell loss was 6 +/- 9% or 4 +/- 3% of a single or a subsequent unit were filtered respectively. Using the PL 100 filter on platelet concentrates, the rate of leukocyte removal exceeded 88% of the initial values. Residual leukocyte counts were 1.4 +/- 0.4 10(6), 6.2 +/- 3.8 10(6) and 1.4 +/- 0.8 10(6) respectively in 6-unit pools, 10-unit pools and machine prepared platelet concentrates. The average platelet loss was 15%. There was no evidence of alteration in the qualitative parameters of red cells or platelets. The filters were easy to handle and the time needed for the whole filtration process was remarkably short.

Blood Cell Count↗
PubMed1987

Oxygen transport to tissue modified by entrapment of an allosteric effector of haemoglobin in erythrocytes.

Oxygen affinity of haemoglobin is modulated by several parameters such as the allosteric effector 2-3 DPG for most mammalians. Inositol hexaphosphate (I.H.P.) exerts the same effect on haemoglobin. A previously developed new methodology for the entrapment of drugs into erythrocytes has been adapted to I.H.P.; it is based on a reversible osmotic shock. I.H.P. loaded red blood cells have characteristics very similar to those of native cells. The decrease in oxygen affinity is related to the dose of encapsulated I.H.P. In piglets, transfusion of such cells has led to an increase of oxygen extraction from haemoglobin. Normal anesthetized animals regulate their oxygen consumption by reduction of cardiac output.

2,3-Diphosphoglycerate↗
PubMed1981

A manual semi-micro method for quantitation of haemagglutination.

A manual semi-micro method for quantitation of haemagglutination is described. It appears to be of wide use for most agglutination reactions usually performed in test tube, including Coombs-test. It is easy to handle and requires the usual equipment of an immunohaematological laboratory. The accuracy obtained for quantitation of antibody concentrations is similar to that of the auto-analyser.

Autoanalysis↗
PubMed1981

Red blood cell antibody screening with groupamatic system. II. A two-step haemagglutination technique using a trypsin-polybren-citrate method.

The trypsin-polybren-citrate (TPC) technique is based on Lalezari's method and has been developed in the Groupamatic equipment to allow the screening of irregular allo-antibodies which are not detectable on this machine by the present routine techniques. TPC screening has two main advantages: it gives more reliable results for Rh, Kell, Lewis and P antibodies than bromelin-methyl-cellulose, and it permits the screening of Duffy and Kidd antibodies, However, although the TPC technique contributes to an improved quality of the automated screening of blood donor samples, it should not be used as the only method when recipient samples are concerned.

Antibodies↗
PubMed1971

[Dental insulants].

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Dental Materials↗