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Biomedical subjects

C Masson

Publications and source records attributed to C Masson.

At least 19 recordsLinked to original sources
PubMed1995

Brain FOS-like expression in developing and adult honeybees.

This study was undertaken to examine the expression of the protooncogene c-fos in an invertebrate, the honeybee. We investigated first the expression of Fos-like proteins, testing different methodologies (immunohistochemistry, immunocytochemistry, immunoblotting). These studies were carried out at the embryonic, nymphal and adult stages. We found immunoreactive bands at approximately 30 kD and 57 kD. The first ones are revealed at the embryonic, nymphal and adult stages. The approximately 57 kD proteins are present at the adult stage. Beside this qualitative variation, intensive modification occurs with a burst of protein expression a few days after the insect emergence. The results suggest that Fos-like proteins are found in the developing and maturing nervous system. Basal level of expression is found in the olfactory pathway, convincing to explore the protooncogene c-fos expression in the cellular and molecular analyses of olfactory plasticity.

Animals↗
PubMed1995

Non-specific cross-reactivity of hydrophobic serum IgE to hydrophobic drugs.

The purpose of this work was to study the involvement of serum hydrophobic IgE in non-specific cross-reactions with hydrophobic drugs such as cyclohexenyl derivatives. Hydrophobic IgE were detected by radioimmunoassay. The results were expressed as the percentage of labelled anti-IgE which were adsorbed to the drug solid phase via IgE of the patient serum. Phenyl-Sepharose IgE-RIA was at 4.6 +/- 0.7%, 125 +/- 6.5% and 17.8 +/- 8.9% in control subjects (n = 24), in atopic patients with positive Phadiatop (n = 30) and in patients with drug allergy (n = 23), respectively. We selected five patients who were allergic to either penicillin, propofol, glafenin or paracetamol and who had a Phenyl-Sepharose IgE-RIA greater than 20%. In these five cases, IgE-RIA were positive (percentage at least twice more than that obtained with control sera) with all the solid phases prepared with hydrophobic drugs such as penicillin, propofol, glafenin, paracetamol and mexiletine. Inhibition of IgE binding by monoethylene-glycol showed that the cross-reactivity was due to hydrophobic binding of IgE to the drug. Three of the five patients were allergic to penicillin and underwent on adverse reaction against another cyclohexenyl derivative, namely propofol and glafenin. In conclusion, we have observed the presence of 'hydrophobic IgE (with positive Phenyl-Sepharose RIA)' in 64% of patients allergic to a hydrophobic drug.

Adsorption↗
PubMed1995

A decreased metabolic clearance of glucose is involved in the hyperglycemic effect of a serum temperature induced factor (TIF).

We have studied the effects of a hyperglycemic temperature induced factor (TIF) on glucose metabolism, in 3 groups of Wistar rats: 10 rats injected with non-heated serum, 10 rats injected with heated serum and 10 rats injected with semi-purified TIF. Seric levels of insulin and glucagon were not modified in rats injected with heated serum. The injection of heated serum induced hyperglycemia (p < 0.0001), a decrease of lactate (p < 0.001) and pyruvate (p < 0.05) levels, and an increase of acetoacetate level (p < 0.001). The levels of beta hydroxybutyrate and amino acids (alanine and glutamine) were not changed. Glucose turn over rate (12.3 +/- 1.3 g/min/kg) and metabolic clearance of glucose (10.0 +/- 0.8 ml/min/kg) were significantly lower in rats treated with heated serum and purified TIF than in controls (respectively, p < 0.05 and p < 0.001). These data suggested that the hyperglycemic effect of heated serum and isolated TIF could correspond to an impaired metabolic clearance of glucose and to an increased gluconeogenesis.

Animals↗
PubMed1995

Epidemiology of adult Still's disease: estimate of the incidence by a retrospective study in west France.

OBJECTIVES: To estimate the incidence of adult Still's disease (ASD) and to specify, if possible, associated factors. METHODS: A retrospective study of the populations of the Brittany and Loire regions in west France was made from 1 January 1982 to 31 December 1991. All internal medicine and rheumatology practitioners of these regions were consulted. RESULTS: Sixty-two (62) cases were reported (93% response). The disease incidence calculated over five years was 0.16 per 100,000 inhabitants in the study population. There was no sex bias (sex ratio 1.06 in ASD v 1.05 in the overall population. The mean age of the study population was 36 years, with two peaks of distribution at 15-25 and 36-45 years. A history of allergy was present in 23% of patients (n = 14). In two patients, it was possible to correlate an environmental allergen to exacerbation of ASD. CONCLUSION: The yearly incidence of ASD was estimated to be 0.16 per 100,000 inhabitants. However, it was not possible to incriminate any infectious, toxic, or genetic factors in exacerbation of the disease.

Adolescent↗
PubMed1995

[Downbeat nystagmus and vertebrobasilar arterial dolichoectasia].

A 66-year-old man presented with a downbeat nystagmus. The underlying cause was unknown. A dolichoectasia of the vertebrobasilar artery was the only identifiable abnormality at Magnetic Resonance Image which also disclosed distortion of the anterolateral aspect of the medulla. Compression of the caudal brain-stem by an enlarged and tortuous vertebrobasilar arterial system may be the cause of downbeat nystagmus in cases unassociated with the more commonly recognized causes.

Aged↗
PubMed1994

A morphometric classification of pupal honeybee antennal lobe neurones in culture.

Both intrinsic (programmed) and extrinsic (non-programmed) factors are thought to play a role in the morphogenesis of neurones in the honeybee antennal lobe (the first relay station in the olfactory pathway) during development. We present here a morphometric and statistical analysis of a large population of pupal honeybee antennal lobe neurones grown in primary culture. Quantitative parameters were used to characterize neuronal shapes. On the basis of such morphometric measurements, an automatic classification allowed three morphological types to be distinguished. Their main characteristics are presented and the role of intrinsic and extrinsic factors in their determination is discussed.

Animals↗
PubMed1994

Monitoring the activity of glucose oxidase during the cultivation of Aspergillus niger using novel amperometric sensor with 1, 1'-dimethylferricinium as a mediator.

1, 1'-dimethylferricinium (DMF+), a deep blue, and stable mediator, was prepared from a water-soluble 1, 1'-dimethylferrocene(DMF):2-hydroxypropyl- beta-cyclodextrin complex via enzymatic oxidation using immobilised bilirubin oxidase. This mediator was superior to other soluble ferrocenes, notably carboxyferrocene, in terms of both solubility (110 mM vs 0.5 mM) and oxidation potential (150 mV vs 300 mV against Ag/AgCl). Although the cyclic voltammogram of DMF+ was electrochemically equivalent to DMF, the use of the former resulted in a significantly lower background current (< 10 nA vs 30 nA). Because of its higher solubility, concentrated stock solutions of DMF+ can be prepared and supplied to the electrode. This is of particular importance when the signal is severely limited by the rate at which the working electrode can oxidase DMF to DMF+. A linear response of current versus units of glucose oxidase (GOD) was obtained up to 0.5 unit/ml. The detection limit was estimated to be 0.03 unit/ml and the response time was 2.5 min or less. The amperometric system was used successfully to follow the GOD activity during the growth of Aspergillus niger a well-known GOD producer. The results obtained correlated well with a standard absorbance-based assay using dichlorophenol-indophenol (DCPIP). The KM of GOD for the glucose in the lysate was measured as 38 mM. A reduced response and higher KM (48 mM) of the cell homogenate, compared to the lysate, illustrated the requirement for the DMF+ and glucose to diffuse across the cell membrane to interact with GOD in whole cells.

Aspergillus niger↗
PubMed1994

Fate of specific nucleolar perichromosomal proteins during mitosis: cellular distribution and association with U3 snoRNA.

In mammalian cells, the nucleoli disintegrate during mitosis and some nucleolar proteins disperse at the periphery of all chromosomes forming a novel class of chromosomal passenger proteins. The nucleolar components which participate in the formation of this perichromosomal layer have been investigated to elucidate the role of these perichromosomal proteins in the assembly and disassembly of the nucleoli. i) Electron microscopy immunolabelling reveals that these proteins are predominantly located in the granular component of the nucleoli during interphase. ii) Immunoprecipitation data suggest that they are distributed at the chromosome periphery in association with U3 small nucleolar RNA (snoRNA). In addition, the distribution of U3 snoRNA visualized by in situ hybridization, is similar to that observed for the perichromosomal proteins. iii) In cells which possess a nucleolar remnant during mitosis, U3 snoRNA and perichromosomal proteins were found both in the perichromosomal layer and in the nucleolar remnant. iv) Some of these proteins are conserved from yeast to man such as fibrillarin and a protein of 52 kDa. v) The location of these proteins observed in yeast by confocal microscopy shows that they are not dispersed during mitosis. Their partition between the two daughter cells is performed by scission of nucleolar structures forming a rod during the budding process. Therefore RNP complexes related to the processing steps of ribosome biogenesis in mammalian cells quit the nucleolus in late G2 and associate with the chromosome periphery until late telophase. They associate in the perichromosomal layer in human and PtK1 cells and both in the perichromosomal layer and the nucleolar remnant in CHO cells.

Animals↗
PubMed1994

Honeybees have putative olfactory receptor proteins similar to those of vertebrates.

Using nested-PCR amplification of honeybee cDNA with degenerate primers derived from mammalian sequences, we have cloned four DNA fragments from putative odour receptor genes. This conclusion is based on high amino acid sequence similarity with published sequences from vertebrates and hydrophilicity profiles in agreement with including these genes in the super family of seven transmembrane domain receptor genes. These results are discussed in the context of the evolution of the olfactory receptor genes.

Amino Acid Sequence↗
PubMed1993

Increased frequency of NGF in sera of rheumatoid arthritis and systemic lupus erythematosus patients.

Nerve growth factor (NGF) levels were measured by a two-site enzyme-linked immunosorbent assay (ELISA) in sera of patients with three autoimmune diseases, rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and thyroiditis. Serum NGF levels were variable (15 pg ml(-1)-1.6 ng ml-1) but not significantly different among these groups compared with control subjects. However the frequency of detectable circulating NGF was significantly higher in RA and SLE patients but not in thyroiditis patients compared with controls. The present data provides evidence for NGF involvement in two autoimmune rheumatic diseases and suggests a possible differential role of NGF as immunomodulatory agent in systemic versus certain organ-specific autoimmune diseases.

Adolescent↗
PubMed1992

[Mental disorders in elderly hospitalized patients. Epidemiological study in an internal medicine department].

This epidemiological transversal study conducted on 100 patients older than 65 years hospitalized in the Internal Medicine department of a University hospital demonstrates the frequency of psychiatric pathology in these patients: dementia 19 percent; other psycho-organic disorders 17 percent; affective disorders 23 percent and other psychological disturbances 4 percent. Thus, 63 percent of this patient population had a mental disorder as defined by the DSM III criteria. These disorders are generally not or imperfectly identified by the internists in charge of these patients.

Aged↗
PubMed1992

[Dysautonomia and multi-systemic atrophy of the nervous system (Shy-Drager's syndrome)].

The clinical expressions of primary autonomic nervous system failure are more or less numerous, orthostatic hypotension being only one of them. Clinical analysis reveals 3 categories of manifestations: pure progressive dysautonomia, dysautonomia associated with Parkinson's disease, and dysautonomia associated with multiple system atrophy of the nervous system also known as Shy-Drager syndrome. Neuropathological studies show that lesions of the efferent autonomic nervous system (tractus intermediolateralis, sympathetic ganglia) are frequently associated with lesions of the central nervous system the role of which in dysautonomia is still imperfectly known. Lesions of the central nervous system may present as genuine Parkinson's disease with Lew bodies or as multiple systemic atrophy with its two best individualized aspects: striatonigral atrophy and olivopontocerebellar atrophy. These various neurological aspects have their counterpart in biochemical abnormalities, prognosis and response to treatment.

Aged↗
PubMed1992

Receptor-mediated endocytosis of the intrinsic factor-cobalamin complex in HT 29, a human colon carcinoma cell line.

A HT 29 cell line derived from human colonic carcinoma was shown to express the intrinsic factor receptor, with about 5000 binding sites per cell and an association constant of 20 x 10(9) 1/mol at pH 7.4 and 4 degrees C. The number of binding sites increased dramatically between 7 and 10 days of culture time. Endocytosis of the intrinsic factor-cobalamin-receptor complex was inhibited by two ways: at 4 degrees C and at 37 degrees C by incubating the cells with vinblastine, monensin and chloroquine. The plasma membrane receptor was cross-linked to [57Co]cobalamin-intrinsic factor and solubilized with Triton X-100. The cross-linked complex had a relative molecular mass of 330 kDa in native PAGE.

Chloroquine↗