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Biomedical subjects

M Masson

Publications and source records attributed to M Masson.

At least 19 recordsLinked to original sources
PubMed1992

Calmodulin antagonists chlorpromazine and W-7 inhibit exogenous cholesterol esterification and sphingomyelinase activity in human skin fibroblast cultures. Similarities between drug-induced and Niemann-Pick type C lipidoses.

In this report we showed that calmodulin antagonists chlorpromazine (CPZ) and W-7 (N-[6-aminohexyl]-5-chloro-1-naphtalenesulfonamide), when added to fibroblast cell cultures, gave rise to a time- and dose-dependent decrease of sphingomyelinase activity. CPZ and W-7 also significantly inhibited LDL- and non-LDL-dependent cholesterol esterification. Addition of these drugs to cell culture medium mimicked what is observed in the genetic disease Niemann-Pick type C. H-7 (1-[5-isoquinonylsulfonyl]-2-methylpiperazine), an inhibitor of protein kinase C and cyclic nucleotide-dependent kinases, had no effect on sphingomyelinase and cholesterol ester formation. Thus the possibility of a modulation of cell sphingomyelin and cholesterol esters by a calmodulin-dependent second messenger system must be considered.

Calmodulin↗
PubMed1992

Glial localization of interleukin-1 alpha in invertebrate ganglia.

1. Mytilus pedal ganglion contains a small population of glial cells that are immunopositive for interleukin-1 alpha. Positively stained fibers can also be seen in the neuropil of these sections. 2. The marine worm Nereis diversicolor also exhibits positive neural immunostaining for interleukin-1 alpha. 3. Both organisms contain hemocytes that contain immunoactivity for interleukin-1 alpha. The study suggests interleukin-1 alpha to be an ancient cytokine given its presence in organisms that evolved significantly earlier than mammals.

Animals↗
PubMed1992

Adult-onset metachromatic leukodystrophy presenting as isolated peripheral neuropathy.

A 38-year-old man presented with weakness of the lower limbs. Electrophysiology revealed a pronounced demyelinating neuropathy. Nerve biopsy disclosed de- and remyelinating lesions and characteristic lamellar inclusions in Schwann cells and macrophages. There was no familial history of neurologic disorder, and impairment of motor evoked potentials was the only sign of CNS involvement. Arylsulfatase A and cerebroside sulfate sulfatase activities in leukocytes and cultures of the patient's fibroblasts were low. The sulfatide loading test also revealed abnormal sulfatide accumulation. This may be the first reported case of adult metachromatic leukodystrophy presenting as peripheral neuropathy.

Adult↗
PubMed1992

Monoclonal antibodies against Nereis virens brain homogenates as probes for isolation and in situ detection of new neurosecretions.

The brain of Nereis contains 26 ganglionic nuclei which produce numerous neurosecretions. Only a few of them have been characterized. The production of monoclonal antibodies was adopted as an approach to discover unknown neurosecretions. Monoclonal antibodies produced against Nereis virens brain homogenates were selected using stepwise ELISA tests first with brain homogenates, then with brain neurosecretions. Eight antibodies specific for Nereis neurosecretions were selected. The results are illustrated with one of these monoclonal antibodies which was directed against a major peak after HPLC purification of brain neurosecretions. This antibody was subsequently used for the in situ detection of recognized epitope(s) in the brain and ventral nerve cord cells.

Animals↗
PubMed1992

[Left prerolandic infarction with initial epilepsy. Development of chronic hallucination psychosis].

A 34-year-old woman had three tonico-clonic seizures and aphasia revealing a left prerolandic infarct. Three weeks later, she began to develop psychiatric symptoms leading to the diagnosis of chronic hallucination psychosis. These symptoms were probably related to epilepsy and their cause was compatible with the diagnosis of interictal psychosis. It has been suggested that kindling of the mesolimbic system could account for psychosis in epilepsy. In our case, however, the sort time interval between the onset of epilepsy and the appearance of psychosis is not in favour of this mechanism.

Adult↗
PubMed1992

[Isolated vertigo disclosing infarction in the area of the posterior and inferior cerebellar arteries].

We report three cases of small cerebellar infarcts mimicking labyrinthine dysfunction. A sudden rotatory vertigo might be the only presenting symptom of a cerebellar infarct. In these cases, the clinical features may closely mimick an acute peripheral labyrinthine disorder. However, the absence of nystagmus or a direction changing nystagmus with different eye position and the normality of caloric responses may be suggestive of a cerebellar infarct. This syndrome may be explained by the involvement of the nodulus, part of the flocculo-nodular complex, that has primary vestibular connections. Cerebellar infarcts mimicking labyrinthine dysfunctions involved usually the cerebellar territory of the posterior inferior cerebellar artery (PICA). Infarcts may be limited to the territory of the medial branch of the PICA which supplies the nodulus.

Arteries↗
PubMed1991

Improved synthesis of [1-14C]acyl-sphingosine-galactose-3-sulfate (sulfatide) for diagnosis of metachromatic leukodystrophy: usefulness of radioscanning.

We report an improved method for the radiolabelling of [1-14C 00acyl-sphingosine-galactose-3-sulfate (sulfatide), requiring preparation of lysosulfatide (sulfogalactosyl-sphingosine) by alkaline hydrolysis of sulfatide and reacylation of the sphingosine amino group with a [1-14C]stearoyl chloride. We found that the yield of labeled sulfatide could be considerably increased using stringent chromatographic conditions for the preparation of lysosulfatide and strict anhydrous conditions for the formation of the acylchloride and its coupling to lysosulfatide. Radioscanning was used at different steps to check the purity of the labeled compounds. Radioscanning was also used to determine the formation of cerebroside when measuring cerebroside sulfate sulfatase activity and sulfatide metabolism in intact fibroblasts in controls and patients with metachromatic leukodystrophy. It could demonstrate and measure with accuracy the cerebroside sulfate storage characteristic of the disease.

Carbon Radioisotopes↗
PubMed1991

Adult forms of metachromatic leukodystrophy: clinical and biochemical approach.

The clinical and biochemical characteristics of metachromatic leukodystrophy (MLD), true adult forms and late juvenile forms which are still living at adulthood, are reviewed as they both are observed in adult Neurology and Psychiatry departments. Mental deterioration is often the first symptom, evolving progressively; and dementia finally occurs. The latency before the appearance of neurological objective symptoms may be long and extend for several years. In many cases, the behavioral abnormalities are the first symptoms. Some of these forms have been diagnosed as schizophrenia. Very seldom, neurological symptoms, especially ataxia, occur without cognitive or psychiatric disturbances. Most of these cases have pyramidal and cerebellar symptoms, at diverse degrees. Seizures can also occur which is some cases can be early symptoms associated to mental deterioration. The association of central and peripheral neurological symptoms is very characteristic of MLD. The peripheral neuropathy is not generally clinically evidenced, but is rarely missing electrophysiologically. Arylsulfatase A determination should be performed for diagnosis as a first step, and confirmed by the accumulation of sulfatide, either by quantitative determinations in urine or by the sulfatide loading test. It is as yet not clear why certain forms have a rather rapid evolution in 5 years, and others have a very protracted course during decades.

Adolescent↗
PubMed1991

Clinical aspects of Niemann-Pick type C disease in the adult.

Niemann-Pick type C disease diagnosed in adult neurology departments may be infantile or juvenile forms with prolonged life span or forms starting at adolescence or adulthood. The evolution is generally slower compared to the infantile cases. Psychomotor retardation is practically constant. Cerebellar ataxia and extrapyramidal manifestations are often found in opposition to pyramidal symptoms. Supranuclear ophthalmoplegia with a down-gaze failure is nearly constant. Cataplexy and other types of seizures may be found during the evolution of the disease. In some cases a psychosis may be the only manifestation for several years; the treatment by psychotropic drugs raises the question of a superimposition of a drug-induced lipidosis. Hepatosplenomegaly is often discrete, contrary to infantile cases. Foam cells or sea-blue histiocytes are a general feature of the disease. Although the primary defect is unknown, diagnosis must be confirmed by the defect in cholesterol esterification from exogenous cholesterol.

Cerebellar Ataxia↗
PubMed1991

[Left pseudothalamic cortical syndrome and pain asymbolia].

We report a case of left pseudothalamic cortical syndrome associated with asymbolia for pain in a right-handed male patient. The responsible lesion, detected at both CT and MRI, was infarction of the superficial territory of the middle cerebral artery, restricted to the posterior insula, the superior aspect of T1, the parietal operculum and the supramarginal gyrus. The ascending parietal gyrus and the thalamus were spared. This case, together with data from the literature, suggest that the somatosensory area II was responsible for the pseudothalamic syndrome. This interpretation is concordant with the hypothesis that S II plays the principal role in passive somatosensory discrimination, whereas S I plays the principal role in active discrimination implying stimulus exploration. The location of lesions that were responsible for asymbolia for pain is discussed. This case and those reported by Berthier et al. (1988), provide arguments in favour of Geschwind's hypothesis which attributes asymbolia for pain to sensory-limbic disconnection due to damage of the insula.

Cerebral Cortex↗
PubMed1991

In vitro fatigue testing of prosthetic ligaments: a new concept.

A cruciate ligament fatigue/wear testing system TTF600 was developed at Ecole Poly-technique in order to reproduce a little better the loading conditions and environment in which they perform. This machine was designed to subject the ligaments to simultaneous tension, bending and torsion. The amplitude of each loading can be adjusted separately. This allows to better define the effect of each loading mode on the viability of a prosthetic device. Six devices can be tested simultaneously in a liquid environment at 37 degrees C. The loading conditions and the behaviour of the prosthesis are monitored by computer.

Anterior Cruciate Ligament↗
PubMed1991

[Type C Niemann-Pick disease: supranuclear ophthalmoplegia associated with deficient biosynthesis of cholesterol esters].

We report a familial case of Niemann-Pick disease type C which lasted until adulthood, and which had the characteristic deficiency in cholesterol esterification from exogenous cholesterol. A review of the literature was performed concerning cases which were seen in adults and were characterized biochemically. This study showed the frequency of supranuclear ophthalmoplegia affecting essentially vertical movements and convergence and of lipid-laden cells in bone marrow which are often sea-blue histiocytes.

Adolescent↗