Search PubMed⌕ Search

Biomedical subjects

M Masson

Publications and source records attributed to M Masson.

At least 127 records · Page 7Linked to original sources
PubMed1984

Alterations in the fatty acid composition of rat brain cells (neurons, astrocytes, and oligodendrocytes) and of subcellular fractions (myelin and synaptosomes) induced by a diet devoid of n-3 fatty acids.

Rats were fed through four generations with a semisynthetic diet containing 1.0% sunflower oil (6.7 mg/g n-6 fatty acids, 0.04 mg/g n-3 fatty acids). Ten days before mating, half of the animals received a diet in which sunflower was replaced by soya oil (6.6 mg/g n-6 fatty acids, 0.8 mg/g n-3 fatty acids) and analyses were performed on their pups. Fatty acid analysis in isolated cellular and subcellular material from sunflower-fed animals showed that the total amount of unsaturated fatty acids was not reduced in any cellular or subcellular fraction (except in 60-day-old rat neurons). All material from animals fed with sunflower oil showed an important reduction in the docosahexaenoic acid content, compensated (except in 60-day-old rat neurons) by an increase in the n-6 fatty acids (mainly C22:5 n-6). When comparing 60-day-old animals fed with soya oil or sunflower oil, the n-3/n-6 fatty acid ratio was reduced 16-fold in oligodendrocytes, 12-fold in myelin, twofold in neurons, sixfold in synaptosomes, and threefold in astrocytes. No trienes were detected. Saturated and monounsaturated fatty acids were hardly affected. This study provides data on the fatty acid composition of isolated brain cells.

Animals↗
PubMed1984

Oxatomide in the treatment of pruritus senilis. A double-blind placebo-controlled trial.

The antiallergic drug oxatomide was evaluated in a double-blind placebo-controlled study in 35 patients with pruritus senilis. The trial was run in the wintertime, and the patients were orally given either 30 mg oxatomide b.i.d. (n = 19) or a placebo (n = 16) for 2 months. Complete suppression or marked improvement of the complaints was experienced by 79% of the patients given oxatomide and by 31% of the control patients. Oxatomide was superior to the placebo in reducing both the duration and the severity of itching. The need of additional topical medication was higher in the placebo group. Somnolence and cramps were each reported by 1 oxatomide-treated patient.

Aged↗
PubMed1984

Synthesis of sisamine and of pseudodisaccharide analogues.

Lividamine and paromamine were converted into two key intermediate ethylenic aldehydes 10a and 10b. Reductive amination of the two aldehydes yielded the protected sisamine 11a and the three analogs 11b, 12a and 12b. These four derivatives were deprotected to yield the four pseudodisaccharides 1a, 1b, 2a and 2b which were less active in vitro than neamine against Escherichia coli ATCC 9637 and Staphylococcus aureus 209P.

Aminoglycosides↗
PubMed1984

Synthesis of pseudotrisaccharides related to ribostamycin.

The three protected sisamine derivatives 2i, 2j and 3, with a free 5-hydroxyl group, have been synthesized. Glycosylation at the 5 position with various pentofuranose derivatives yielded after deprotection of the 6a approximately i ribostamycin related aminoglycoside. These pseudotrisaccharides showed only low antibacterial activities with respect to the parent compounds.

Anti-Bacterial Agents↗
PubMed1984

[Spontaneous epidural hematoma in panarteritis nodosa].

Four years after the first sign of panarteritis nodosa, a 60 years old woman presented severe pain in the lower thoracic spine followed by motor, sensory and sphincter paralysis. With corticosteroid therapy, condition improved 24 hours later, but myelography revealed an incomplete block from T9 to L1, by an epidural hemorrhage. In the course of panarteritis nodosa, one case of epidural hemorrhage, and a few cases of subarachnoid hemorrhage of the spinal canal have been described.

Female↗
PubMed1984

[Acquired cerebral toxoplasmosis: 3 anatomoclinical cases].

Clinical and pathological findings in three adults with toxoplasmosis of the central nervous system are reported. Symptoms and signs in the first patient, a Haitian woman who had lived in France for 2 years, were suggestive of a right hemispheric space-occupying process. The second case was a woman treated for Hodgkin's disease who showed symptoms and signs of a meningoencephalitis. The presenting lesion in case 3 mimicked a tumor of the posterior fossa. Analysis of these 3 cases and of those previously reported underlines: 1) diagnostic difficulties, particularly in immunodepressed patients; 2) the effectiveness of immunoperoxidase for pathological diagnosis; 3) the poor prognosis due to absence of a specific treatment.

Adolescent↗
PubMed1984

[Transformation of cerebral infarction into hemorrhage during x-ray computed tomography in a patient under anticoagulant treatment].

Repeated CT scans provide the only means of confirming the initial ischemic nature of a cerebrovascular accident and its eventual course towards a hemorrhage. Precise data can be obtained as to the frequency of this complication as a function of factors such as the embolic origin of the infarct or associated anticoagulant therapy. The present case shows that contrast medium, at least in patients receiving anticoagulant treatment, may constitute a risk factor by increasing the possibility of transformation of a pale infarct into a hemorrhagic one. Possible relevant properties of iodized contrast media with respect to this type of complication are considered.

Aged↗
PubMed1984

[Cerebral infarction in the area of the anterior choroidal artery with oculomotor disorder].

A 84-year-old diabetic man had a complete right-sided hemiplegia with ipsilateral hypoesthesia and vertical diplopia, but no aphasia or hemianopia. The CT scan showed a low-density area in the posterior limb of the left internal capsule, in the territory of the anterior choroidal artery. The mechanism of diplopia is discussed and is attributed to the involvement of the mesencephalic territory of the anterior choroidal artery.

Aged↗
PubMed1984

[2 cases of post-measles myelitis].

Two cases of a very rare complication of rubella i.e. a strictly spinal cord lesion developing during the course of the viral infection, are reported. In the first case, there was a flaccid paraplegia which incompletely regressed after two months. In the second case there were only sensory disorders and sphincter disturbances and recovery was complete after one month. The post-eruption encephalomyelitis lesions are of uncertain paphogenesis but the most common hypothesis suggested is that of a delayed hypersensitivity mechanism involving a cell-mediated immunologic reaction. The prognosis of these post-injection neurologic manifestations is difficult to assess, but spinal cord lesions could have a good prognosis.

Adolescent↗
PubMed1983

Kinetic studies of aminoglycoside acetyltransferase and phosphotransferase from Staphylococcus aureus RPAL. Relationship between the two activities.

In the Staphylococcus aureus strain harbouring the plasmid RPAL, the resistance to aminoglycoside antibiotics results from two inactivating reactions catalyzed by a 6'-N-aminoglycoside acetyltransferase and a 2"-O-amino-glycoside phosphotransferase. These enzymes are copurified with a constant ratio between the two activities, the purification process consisting in affinity chromatography, native electrophoresis and gel exclusion chromatography. The kinetic mechanisms of each activity have been determined from studies of initial velocities, as well as product and dead-end inhibitions. Both activities follow a random rapid equilibrium mechanism. The substrates and cofactors of one reaction have been tested as effectors of the other reaction. No interaction between the two activities has been observed. However, the GTP cofactor of phosphotransferase protects, at weak concentrations, the acetyltransferase against thermal inactivation, which suggests that the two activities may be associated.

Acetyltransferases↗
PubMed1983

Age-related reproductive decline in the male Japanese quail.

A series of experiments was conducted to study the decline in reproduction associated with age in the male Japanese quail. In Experiment 1, eggs were collected from pairs that were 28, 56, 107, and 149 weeks of age. Pairs that were 56 weeks of age or older showed a sharp drop in fertility and hatchability. Subsequent experiments were designed to study the endocrine and behavioral basis for this decline in the male. In Experiment 2, males that were between 23 and 70 weeks of age were tested for mating behavior, plasma testosterone was measured, and testes wet weight was determined. There were no significant differences between the age groups. However, samples taken from an additional group of males 168 weeks of age showed significantly (P less than 0.05) lower serum testosterone and testes weight. Therefore, the third experiment was designed to include age groups of males between 4 and 126 weeks of age in order to further examine this decline in males older than 70 weeks of age. There was a significant (P less than 0.05) drop in this number of males showing sexual behavior and of those males showing sexual behavior; the quantity of mating activity also declined. Plasma testosterone was reduced in the older groups; however, the change was not significant. In addition, the size of the cloacal gland, an androgen-dependent organ, declined with age (P less than 0.05). These results argue that the age-related reproductive decline may have behavioral as well as endocrine basis. Possibly, the behavioral changes may result from altered receptor sensitivity at the level of areas of the brain, which control reproductive behavior, and at the level of the testes, which affect hormone production and spermatogenesis.

Aging↗
PubMed1983

[Effect of the linolenic acid content of the mother's diet on the polyunsaturated fatty acid composition of subcellular fractions in brain development in the rat].

In order to determine precisely the respective roles of linolenic acid and linoleic acid in the maternal diet on rat brain subcellular fractions during development, we used two diets with different percentages of linolenic acid (18:3 n-3). The animals were fed peanut oil (group A) or soybean oil (group B) during pregnancy and throughout lactation. Nature and amount of essential fatty acids had no incidence on saturated and monounsaturated fatty acid distributions in myelin, synaptosomal, mitochondrial and microsomal fractions. In adult rats, all subcellular fractions are marked by an increase of n-3 fatty acid and a decrease of n-6 fatty acid levels in group B compared to group A. In 15-day-old animals, on the contrary, only the synaptosomal fractions are significantly affected by the diet. Independent of diet, brain development is marked by a decrease of n-6 fatty acids in all subcellular fractions; on the other hand, the n-3 fatty acid level is increased in the synaptosomal and mitochondrial fractions, and decrease in the myelin and microsomal fractions. The sum of (n-3 + n-6) fatty acids remains constant in group B and in group A in all subcellular fractions. Finally, under our experimental conditions, we found no marked effect of diet composition upon linoleic acid conversion to arachidonic acid; only the delta 4-7-10-13-16-docosapentaenoic acid (22:5 n-6) level decreased in group B. delta 7-10-13-16-19-Docosapentaenoic acid (22:5 n-3) seemed to be a better substrate for delta 4 desaturase than delta 7-10-13-16-docosatetraenoic acid (22:4 n-6).

Animals↗
PubMed1983

[Anterior choroidal artery syndrome. Clinical and computed tomography study of 4 cases].

The author choroidal artery syndrome is a rare disorder associating, in its complete form, a hemiplegia, a hemianesthesia, and a homonymous lateral hemianopia. Four cases are reported in which the diagnosis was confirmed by a CT scan, which demonstrated a low density area in the posterior part of the posterior limb of the internal capsule, sparing the thalamus medially, and extending laterally to the apex of the pallidum thus corresponding to the area supplied by the anterior choroidal artery. The incomplete forms of this syndrome and clinicopathological correlations are discussed.

Aged↗
PubMed1983

[Anterior choroidal artery syndrome. Neuropsychological study of 4 cases].

A neuropsychological study was carried out in 4 cases of infarction in the territory of the anterior choroïdal artery. In 3 cases the lesions were on the right side. A syndrome of the minor hemisphere was present with severe visual neglect, constructional apraxia, alexia due to disorders of visuo-spatial strategy, anosognosia and motor impersistence. In the case with a left-sided lesion there was no neglect but a mild aphasia with impaired fluency, semantic paraphasias, perseveration and a decreased psycho-linguistic ability. The mechanisms of neglect in right-sided lesions are considered.

Aged↗
PubMed1982

Peripheral nerve cells in culture rich in Schwann cells incorporate and metabolize trans-unsaturated fatty acid (elaidic acid) as well as physiological dis isomer (oleic acid).

A culture of peripheral nerve cells enriched in Schwann cells was obtained from sciatic nerve in normal and demyelinating trembler mutant. These cells incorporated and metabolized a non-physiological trans fatty acid (elaidic aid) as well as the physiological cis isomer (oleic acid). Both acids were incorporated similarly in all lipids studied (phosphatidylcholine was a very potent acceptor) only cholesterol-esters' formation was slightly reduced from elaidic acid. Both acids were partially degradates into sub-units, in turn used for synthesis of new fatty acids. However elaidic acid was less degraded by the cells thus providing more C14:1, C16:1 fatty acids and less cholesterol. The sub-units were also used to provide very long chains, saturated and mono-unsaturated; only synthesis of nervonic acid was at variance when using oleic and elaidic acids. The presence of elaidic acid diminished the elongation-desaturation of essential fatty acids. No major differences were found between control and trembler cells, however cholesterol-esters' synthesis was slightly enhances in the mutant cells, when using both acids.

Animals↗