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Biomedical subjects

G Simonin

Publications and source records attributed to G Simonin.

46 records · Page 3Linked to original sources
PubMed1981

Stimulation by tubulin of an adenylate cyclase from murine plasmacytoma.

Different brain tubulin preparations were shown to stimulate membrane-bound adenylate cyclase from the murine plasmacytoma MOPC 173. Purified tubulin devoid of microtubule-associated proteins and of nucleoside-diphosphate kinase activity was responsible for this stimulation. Activation of the basal adenylate cyclase activity occurred in less than 2 min at 32 degrees C and was amplified by a 4 degree C preincubation of tubulin with plasma membranes. Tubulin affected the Km and the V of the enzyme and was shown to be associated with the membrane during the activation phenomenon. Tubulin was more active on the basal adenylate cyclase activity than that stimulated by fluoride or guanosine 5'-[beta, gamma-imido]triphosphate. GTP has no effect on the tubulin-stimulated enzyme.

Adenylyl Cyclases↗
PubMed1981

Plasma membrane enzymes in BALB/c lymphomas with either T or B cell properties, I. 5'-Nucleotidase.

Comparison of membrane bound 5'-nucleotidase activity has been made in crude extracts and plasma membrane fractions from Abelson virus transformed lymphomas, IgM, IgG and IgA producing plasmacytomas and from thymomas with different surface antigen markers. 5'Nucleotidase activity was characterised by the following criteria : 1) optimal pH for enzyme activity, 2) specificity of 5'AMP as a substrate at the optimal pH, 3) specific inhibition of the enzyme by alpha beta methylene ADP, 4) inhibition by EDTA. 5'-Nucleotidase was found to be present on the following B cells : Abelson virus transformed lymphomas, plasmacytomas and LPS-stimulated blasts from nu/nu spleens. The enzyme was also found in one thymoma Lut 13, but it was absent from all the other thymomas studied. A possible relationship between 5'-Nucleotidase and purine metabolism in lymphocyte subpopulations is suggested by the results.

5'-Nucleotidase↗
PubMed1980

[Optimal trypsin concentration for rat heart cell cultures].

Three concentrations (0.5, 1 and 2 per 1000, w/v) of a single batch of trypsin were compared regarding their influence on cultured cardiac cell of newborn rats. All three allowed to obtain cardiac cells in good conditions, as evidence by beating frequencies and [16-14C]-palmitate beta-oxidation. However the 0.5 per 1000 concentration appeared to be the optimal one, inducing a smaller loss of cells during the first two days in culture.

Animals↗
PubMed1977

[Thrombocytosis and cancer. Apropos of a chronological series of 100 patients].

The authors report a personal chronological series of 100 cancer patients submitted to an analytical study, and noted thrombocytosis in 18% of cases. They attempt to draw up a correlation between the presence of increased platelets, and the site of the primary tumour, its spread, the state of anemia or iron deficiency in these patients. During a general review of the literature, they compare their results with those of various american and german series and report the various pathogenic hypotheses suggested upto date. They emphasise the fact that routine platelet counts may be of great interest in the detection of certain early carcinomas in spite of the generally moderate levels of thrombocytosis observed. They therefore have a place in routine health checks.

Blood Cell Count↗
PubMedDate not supplied

[Neonatal diabetes. Apropos of 2 cases].

Diabetes mellitus uncommon in the newborn infant. There are two entities: a transient form and a permanent one. Differenciation is difficult. Transient diabetes, apparently the more common of the two, results in complete recovery. Permanent diabetes requires continued insulin therapy. The clinical presentations of these patients in the first days to weeks of life are similar in that the infants are small for gestational age, hyperglycemic, dehydrated and only rarely have ketonemia or ketonuria. However, the aetiology of the syndrome is unknown. The authors report two cases of permanent diabetes mellitus identified in the first two months of life, and still treated at thirty months of life.

Diabetes Complications↗
PubMedDate not supplied

[Course of serum levels of free thyroid hormones in children from 10 days to 2 years of age].

We have been studying a population of 95 normal children aged 10 days to 2 years, in order to determine the normal values of free thyroid hormone in this class of age. The concentrations were measured by radioimmunoassay (Lepetit system). Free T3 (FT3) appears remarkably stable, with a mean at 4,92 pg/ml (3,23 - 7,50 mg/ml at +/- 2SD). These concentrations are significantly higher than those of adult. Free T4 (FT4) shows a significant decrease over the first month of life, with a mean at 14,31 pg/ml (10,27 - 19,94 pg/ml at +/- 2SD). There is no significant variation between the age of one month and 2 years. The mean is 10,51 pg/ml (7,00 - 15,79 pg/ml +/- 2SD).

Aging↗