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D Monard

Publications and source records attributed to D Monard.

72 records · Page 4Linked to original sources
PubMed1986

A glia-derived neurite promoting factor with protease inhibitory activity belongs to the protease nexins.

A glia-derived neurite promoting factor (GdNPF) has serine protease inhibitory activity and in addition regulates the migration of neuronal cells. cDNA cloning of GdNPF is necessary for studying the physiological relevance and the mode of action of this protein and similar cell-derived protease inhibitors. Xenopus oocytes injected with rat glioma cells mRNA release this inhibitor. A rat cDNA clone coding for the previously purified glia-derived neurite promoting factor (GdNPF) was isolated upon hybridization-selected translation, followed by immunoprecipitation. The correct identity of this cDNA is proven by the presence of a sequence coding for a tryptic fragment from pure GdNPF. Northern analysis indicates that GdNPF mRNA is found almost exclusively in brain tissue and could be developmentally regulated. The same cDNA clone has been used to isolate full-length rat and human GdNPF cDNA. The deduced human GdNPF amino acid sequence indicates that the protein is a member of a family of cell-derived protease inhibitors named protease nexins.

Amino Acid Sequence↗
PubMed1986

Modulation of granule cell migration by a glia-derived protein.

Cultured explants from early postnatal mouse cerebellum were used to examine the influence of a 43-kDa glia-derived neurite-promoting factor (GdNPF) on the migration of [3H]thymidine-labeled granule cell neurons. GdNPF, which is a potent serine protease inhibitor, significantly reduced the extent of granule cell migration in a dose-dependent manner. This effect could be neutralized by addition of thrombin, which binds GdNPF. Other protease inhibitors such as aprotinin, hirudin, soybean trypsin inhibitor, leupeptin, 6-aminocaproic acid, and D-Phe-Pro-ArgCH2Cl do not show this inhibitory effect. These results demonstrate that a glia-derived protein can regulate the migration of postmitotic neurons, an important cellular event in the development of the nervous system.

Animals↗
PubMed1985

[Oxygen home therapy in chronic respiratory insufficiency. Report of experience with 70 patients].

The effect of home long-term oxygen therapy has been evaluated in 70 patients (52 men and 18 women) with chronic respiratory insufficiency due to chronic obstructive pulmonary disease. The mean duration of the observation period was 17.5 months, lasting at least 6 months and in a few cases over 40 months. The cumulative death rate was 22.6% in the first 12 months, 36.5% after two years and 40.7% in the third year. Compared to a previous period of 19.5 months there was an obvious reversal in hypoxemia, an increase in physical capacity and a reduction in the hospitalization rate. Patients with marked respiratory failure and with the clinical features of the "blue bloater" type of chronic bronchitis responded better to the home oxygen therapy than a group of "advanced pink puffers" with hypercapnia and high pulmonary arterial pressure. The present results do however confirm the beneficial effects of long-term domiciliary oxygen administration, and should encourage critical use of this new therapeutic regimen according to the indications so far recommended.

Aged↗
PubMed1985

A glia-derived neurite-promoting factor with protease inhibitory activity.

Brain cells and glioma cells in culture release a protein which induces neurite outgrowth in neuroblastoma cells. This neurite-promoting factor (NPF), which has been purified from serum-free glioma conditioned medium, has an apparent mol. wt. of 43 000. NPF inhibits urokinase as well as plasminogen activator-dependent caseinolysis or fibrinolysis. NPF and urokinase form an SDS-resistant complex. The fact that this glia-derived NPF is a potent protease inhibitor indicates that glial cells modulate the proteolytic activity associated with neuronal cells and suggests that this phenomenon is one of the biochemical events involved in the regulation of neurite growth.

Animals↗
PubMed1977

Morphological differentiation of neuroblastoma cells in medium supplemented with delipidated serum.

Neuroblastoma cells have been found to extend neurites when grown in a medium supplemented with delipidated fetal calf serum. Fetal calf sera from different commercial sources give rise to marked differences in the degree of this spontaneous morphological differentiation. The phenomenon can be prevented by the addition of certain fatty acids; oleic acid is especially effective. The serum-free conditioned medium from glial cells can quantitatively antagonize the effect of oleic acid, suggesting that glial factor activity could be due to components [lipids and/or macromolecular factors(s)] that are able to modify the properties of the neuroblastoma cell membrane.

Blood↗
PubMed1973

Glia-induced morphological differentiation in neuroblastoma cells.

Glial cells release a factor into their culture medium that induces a high degree of morphological differentiation in neuroblastoma cells under normal growth conditions. This phenomenon is not correlated with a change in intracellular adenosine 3':5'-cyclic monophosphate or in the rate of cell growth. Media from other cell lines tested induce less morphological differentiation or have no effect.

Animals↗
PubMed1973

Cyclic 3',5'-adenosine monophosphate phosphodiesterase of Escherichia coli.

The cyclic 3',5'-adenosine monophosphate (c-AMP) phosphodiesterase from Escherichia coli has been partially purified. The enzyme has an apparent molecular weight of 30,000, a Michaelis constant of 0.5 mM c-AMP, and a pH optimum of 7. The partially purified enzyme requires for activity the presence of a reducing compound and of either iron or a protein which seemingly acts as iron carrier.

Acetone↗