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Biomedical subjects

R Dumas

Publications and source records attributed to R Dumas.

At least 217 records · Page 12Linked to original sources
PubMed1990

Miller-Fisher syndrome and pontine abnormalities on MRI: a case report.

The authors report a patient with Miller-Fisher syndrome in whom MRI of the brain stem showed increased signal density on T2 sequence anterior to the fourth ventricle, on the right and the left. The authors discuss the relation between these MRI abnormalities and some clinical features of the syndrome. The authors believe that the cardinal features of Miller-Fisher syndrome are due to peripheral nervous system dysfunction, but that this does not preclude a possible central nervous system involvement.

Ataxia↗
PubMed1990

Hemiballismus revealing multiple sclerosis in an infant.

The authors report a case of a 15-month-old infant who presented a left hemiballismus associated with left Marcus-Gunn pupil, and retrobulbar optic neuritis, which disappeared spontaneously in 7 days. Six weeks later, the infant experienced a mild paraparesis with a palsy of the left sixth cranial nerve, which disappeared following steroid therapy. Evoked visual potentials elicited abnormal latencies; cerebrospinal fluid (CSF) showed a rise in white cells and oligoclonal bands. According to the usual classification, this case corresponds to definite multiple sclerosis. The fact that hemiballismus was the initial clinical feature in an infant makes this observation very interesting. In the literature, eight cases of hemiballismus in patients with multiple sclerosis are reported; however, only two cases of multiple sclerosis in infancy have been published, making our case report of particular interest.

Evoked Potentials, Visual↗
PubMed1990

[Value of sphenoidal electrodes in the EEG diagnosis of herpes encephalitis].

EEG features in acute necrotizing encephalitis show periodic activity, localized in the temporal area with a slow background activity. Nevertheless, this periodic activity is transient and may lack. Sphenoidal electrodes study of the internal face of the temporal lobe could record such activity in herpes encephalitis. Sphenoidal electrodes were inserted in 4 patients known to have herpes encephalitis. In 2 cases, periodic discharges were observed both on the surface and sphenoidal electrodes, while in 2 cases, periodic discharge was observed under only sphenoidal electrodes. Faced with uncertain diagnosis of herpes encephalitis, it may be useful to insert sphenoidal electrodes to record deep periodic discharges, not seen on surface electrodes, in order to confirm the diagnosis.

Adult↗
PubMed1990

Comparison of the Kinetic Behavior toward Pyridine Nucleotides of NAD-Linked Dehydrogenases from Plant Mitochondria.

In this article we compare the kinetic behavior toward pyridine nucleotides (NAD(+), NADH) of NAD(+)-malic enzyme, pyruvate dehydrogenase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and glycine decarboxylase extracted from pea (Pisum sativum) leaf and potato (Solanum tuberosum) tuber mitochondria. NADH competitively inhibited all the studied dehydrogenases when NAD(+) was the varied substrate. However, the NAD(+)-linked malic enzyme exhibited the weakest affinity for NAD(+) and the lowest sensitivity for NADH. It is suggested that NAD(+)-linked malic enzyme, when fully activated, is able to raise the matricial NADH level up to the required concentration to fully engage the rotenone-resistant internal NADH-dehydrogenase, whose affinity for NADH is weaker than complex I.

Journal Article↗
PubMed1990

Influence of macrolide antibiotics on the chemiluminescence of zymosan-activated human neutrophils.

No statistically significant changes in the chemiluminescence response of the whole blood were noted following in vitro treatment with 0, 2, 10, 25, or 50 micrograms/ml of erythromycin, josamycin, miomycin, roxithromycin, and spiramycin. These results suggest that these macrolide antibiotics are unlikely to impair the phagocytizing abilities of human neutrophils, in agreement with previous findings indicating their lack of influence upon neutrophil chemotaxis.

Anti-Bacterial Agents↗
PubMed1990

[Epilepsy and bilateral occipital calcifications: 3 cases].

We report 3 cases of epilepsy with bilateral occipital calcifications followed up for several years. These cases were compared with 21 published cases and were found to differ from the classical Sturge-Weber syndrome on several points: 1) the disease appeared around the age of 5 years and consisted of focal epilepsy without neurological or mental disorders; 2) the epilepsy was easy to control during 2 to 5 years. This was followed by a diffuse encephalopathy with severe, treatment-resistant epilepsy, Gerstmann's syndrome, optic ataxia, cerebellar syndrome and slow activity at EEG. It appears from these 3 cases that: 1) occipital calcifications may be unilateral at the onset of the disease; 2) visual evoked potentials are affected at a late stage, and 3) CT scans are of considerable value in the prognosis of benign epilepsy in childhood.

Brain Diseases↗
PubMed1990

[Cholecystocolic fistula: from symptoms to diagnosis].

We report 2 patients with a cholecystocolic fistula in whom diametrically opposite symptoms (isolated steator-rhea, jaundice and fever) were responsible for important clinical difficulties. These fistulae are far less common than cholecysto-duodenal fistulae. Endoscopic retrograde cholangiography was performed because of abnormal liver tests and led to diagnosis in both cases. Classical aerobilia was absent in both of our cases. Barium enema was disappointing (case n. 1), whereas technetium 99m scintiscan visualized the fistula (case n. 2). Two therapeutic approaches are possible in the case of cholecystocolic fistula. Surgery, usually combining cholecystectomy and extraction of common bile duct stones with the treatment of the fistula, may be performed systematically or in case of failure of sphincterotomy (case n. 1). On the other hand, endoscopical sphincteromy during endoscopic retrograde cholangiography, which, by reducing increased biliary pressure, may be sufficient to achieve spontaneous closure of the fistula in an elderly or high risk patient (case n. 2).

Aged↗
PubMed1990

[Dense middle cerebral artery: etiologic significance and prognosis].

Five cases of infarction in the territory of the middle cerebral artery (MCA) are reported. The main feature common to these 5 cases was the presence at CT without contrast injection, in the first 24 hours, of a spontaneous hyperdensity of the ipsilateral MCA. In one case, angiography demonstrated that this hyperdensity was associated with occlusion. In 2 other cases, doppler examination showed occlusion of the internal carotid artery. The transient character of these radiological findings is underlined. In the acute phase of an infarction, hyperdensity of the MCA at an early CT scan without contrast injection suggests an occlusive mechanism and massive infarction with poor clinical outcome.

Acute Disease↗
PubMed1989

Purification and characterization of acetohydroxyacid reductoisomerase from spinach chloroplasts.

Acetohydroxyacid reductoisomerase was purified over 400-fold to a specific activity of 62 nkat.mg-1, with 2-aceto-2-hydroxybutyrate as substrate, from the stroma of spinach leaf chloroplasts. The enzyme was not intrinsically membrane bound. The native enzyme was a tetramer with a subunit Mr of 59,000. The activity was optimum between pH 7.5 and 8.5. The apparent Km for 2-acetolactate was 25 microM and for 2-aceto-2-hydroxybutyrate was 37 microM. The enzyme required Mg2+ and the Vmax. was attained at physiological Mg2+ concentrations. NADP+ competitively inhibited the reaction when NADPH was the varied substrate. The native enzyme eluted from Mono-Q ion-exchange resins as three distinct peaks of activity. This elution pattern was preserved when the peaks were combined, dialysed and re-chromatographed. Each form exhibited identical Mr of 59,000 after SDS/polyacrylamide gel electrophoresis (PAGE), whereas they were easily distinguishable from each other after PAGE under non-denaturing conditions. These results provide evidence for the existence of multiple forms of acetohydroxyacid reductoisomerase in chloroplasts isolated from spinach leaves.

2-Acetolactate Mutase↗
PubMed1989

[Epidemiology of cerebrovascular accidents. According to Dijon's registry (1985-1988)].

The results of a 4-year prospective study of stroke in a community of 140,000 people are reported. Eight hundred and forty-two strokes were recorded, 70 per cent in University Hospitals, 20 per cent in private hospitals and 10 per cent at home. Ninety-four per cent of the patients had a CT scan. The annual incidence of stroke was 145/100,000 people, whereas the incidences of infarct, cerebral haemorrhage and subarachnoid haemorrhage were 121, 21 and 6.6/100,000 people respectively. These results, compared with those of other registers, clearly show the superiority of population-based registers over hospital-based registers.

Adolescent↗
PubMed1989

Effect of sulphate on glutamate synthesis by intact spinach (Spinacia oleracea) chloroplasts.

During the course of NH4+ (or NO2-)-plus-alpha-oxoglutarate-dependent O2 evolution in spinach (Spinacia oleracea) chloroplasts, glutamate was continuously excreted out of the chloroplasts. Under these conditions, for each molecule of NO2- or NH4+ which disappeared, one molecule of glutamate accumulated in the medium and the concentration of glutamate in the stroma space was maintained constant. SO4(2-) (or SO3(2-) behave as inhibitors of NH4+ incorporation into glutamate by intact chloroplasts. This considerable inhibition of glutamate synthesis by SO4(2-) was correlated with a rapid decline in the stromal Pi concentration. The reloading of stromal Pi with either external Pi or PPi4- relieved SO4(2-)-induced inhibition of glutamate synthesis by intact chloroplasts. It was concluded that SO4(2-) induced a rapid efflux of stromal Pi out of the chloroplast, leading to a limitation of ATP synthesis and therefore to an arrest of ATP-dependent glutamine synthetase functioning.

Brassica↗
PubMed1989

[Familial benign neonatal seizures: EEG, clinical, prognosis and genetic features].

The authors describe 3 families in which several members presented convulsions exclusively during the neonatal period. The EEG and clinical findings showed typical short neonatal convulsions lasting several months and with no apparent etiology. The dominantly inherited transmission is certain. Prognosis is very good, although 14% of the cases in the literature present an onset of epilepsy after 20 years of age. Even though this phenomenon is unusual, the rarity of its description probably stems from lack of knowledge rather than low incidence. We thus would like to show that, even in the neonatal period, familial epilepsy can occur.

Female↗
PubMed1989

Stroke in a French prospective population study.

Since 1985 there has been a Stroke Registry in Dijon to record every stroke occurring in the population of a city of 140,000 inhabitants. The survey has been exhaustive and included the numerous sources of information as well as CT scanning. The annual incidence is 145/100,000 with an annual specific incidence of 170/100,000 in men, 126/100,000 in women. The annual specific incidence shows a female preponderance until 30 years of age, after which the males lead from the age of 30 to 80, when the rates become equal. Sixty-eight percent of strokes produced by infarct, 12% by lacunae, 5% by subarachnoid hemorrhage and 15% by cerebral hemorrhage. Differences exist in this distribution, with the preponderance of young people in subarachnoid hemorrhage, and cerebral hemorrhage is commoner in the 5th decade while infarct increases with age in both sexes. Infarct appears commoner during winter, transient ischemic attacks during summer, while cerebral hemorrhage has a constant incidence during the year. Mortality is high mainly during the 1st month with 12.5% during the 1st week, 21.5% the 1st month and 30% the 1st year. Our results are in the mean similar to white occidental countries, but opposite to those observed in Japan; they emphasize the importance of the lacunar syndrome, and the seasonal variations in different types of stroke.

Adult↗
PubMed1989

[Epilepsy with rolandic paroxysms and migraine, a non-fortuitous association. Results of a controlled study].

The incidence of migraine was studied in 4 groups of patients: patients with centro-temporal epilepsy, patients with absence of epilepsy, patients with partial epilepsy, and non-epileptic patients with a history of cranial trauma. Migraines were present in 62% of the patients with centro-temporal epilepsy, 34% of the patients with absence of epilepsy, 8% of the patients with partial epilepsy and 6% of the patients with cranial trauma. These results suggest that the association of centro-temporal epilepsy and migraine is non-fortuitous as well as, to a lesser degree, absence of epilepsy and migraine. The authors discuss the role of serotonin in the association epilepsy-migraine and suggest that centro-temporal epilepsy might be a feature for the diagnosis of migraine.

Adolescent↗