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Biomedical subjects

M Dumas

Publications and source records attributed to M Dumas.

At least 181 records · Page 10Linked to original sources
PubMed1988

[Study of antiglycolipid antibodies in IgM monoclonal dysglobulinemias associated with peripheral neuropathy].

An immunological mechanism may be responsible for the peripheral neuropathies related to IgM monoclonal gammopathies. Myelin-associated glycoprotein (MAG) has been found to be one the main target antigens for these paraproteinemias. Glycosphingolipids of peripheral nerve have been also found to be targets for these antibodies, especially a sulfated glycosphingolipid containing glucuronic acid (GLSG) specific for peripheral nerve. Crossed reactivity has been found between MAG and GLSG. Anti-glycolipid antibodies were determined in 14 patients with IgM gammopathy and polyneuropathy. Glycosphingolipids from human peripheral nerve were purified and chromatographed by thin-layer chromatography for immunodetection of the antibodies. The 12 patients who had GLSG antibody activity had a clinical status identical to the reported cases of dysglobulinemic neuropathies with anti-MAG antibodies.

Adult↗
PubMed1988

[Tropical African neuromyelopathies: 61 studied cases in the Ivory Coast].

Sixty one cases of tropical myeloneuropathies (TNM) from Abidjan, Ivory Coast, are reported. The mean age of patients was 35 years. The socioeconomic level was often very low and puerperality was a common initiating factor. Several clinical forms are noted: pure pyramidal (16 cases), pure ataxic (11 cases), sensory motor polyneuritis (8 cases), combined sclerosis of the spinal cord (1 case), ataxic polyneuritis (25 cases). In fact the extent of the pathobiological process was more severe as shown by slowings of peripheral motor nerve conduction velocities, prolonged central conduction time determined after cortical and spinal stimulations, and a severe sensory axonal impairment on nerve biopsies. These changes were observed with varying degrees in all clinical forms. As long as the etiological factors of TMN are not known (preventing from the possibility to split this disease in several entities) it is preferable to speak about one global disorder and not isolated various clinical forms (e.g. particulary: tropical spastic paraplegia). HTLV-I retrovirus seems to play a limited role in the etiology of TMN in Ivory Coast (1 positive case).

Adolescent↗
PubMed1988

[The concept of tropical neuromyelopathy].

Since the beginning of this century, the concept of tropical neuromyelopathy (T. N. M.) was progressively elaborated in tropical areas. This disorder is constituted by three main clinical syndromes (e.g.: polyneuropathy, spastic paraplegia, ataxia). Abnormal clinical, electrophysiological and pathological features, observed in all clinical forms argue in favor of a diffuse pathobiological process of the nervous system. The association with positive HTLV-1 serology, has recently induced a great interest for the spastic forms of T. N. M. Tropical spastic paraplegia tend to be individualized. This attitude differs from the global concept of T. N. M. which allows gathering similar clinical syndromes. This T. N. M. group should be kept intact until the discovery of new etiologies. Toxic (manioc, lathyrism) or deficiency (hypovitaminosis, malabsorption) causes are incriminated. Otherwise etiologies are unknown.

Ataxia↗
PubMed1988

[Hemiplegic forms of human African trypanosomiasis].

Hemiplegic forms of human African trypanosomiasis are unusual. From 1963 to 1987, 14 cases have been reported in the literature. One may be mistakenly led to look for a space-occupying lesion when clinical features include hemiplegia, vascular shift from median line during arteriography, focal EEG anomalies and intracranial hypertension. The discussion on diagnosis also covers subacute or chronic meningo encephalitis (tuberculosis syphilis or fungal infection). CT scanner findings suggest the association of a massive demyelination of centrum semiovale, with cerebral oedema.

Animals↗
PubMed1988

[Human African trypanosomiasis in the north of Benin. A preliminary serologic survey].

Atacora Province has been for a long time a focus of human trypanosomiasis in the People's Republic of Benin. If the prevalence has appreciably decreased in the 1960s on account of the experienced methods of tracking down and a sustained supervision, it is easy to establish and to fear today the waking and even the extension of the historic focus formerly called "Foyer Atacora". Since 1974, new patients in second period of the infection are tracked down each year; they particularly come from the localities of Tanguieta and Materi. This suggests that sleeping sickness still persists in the North Country; that is the reason why it appears interesting to evaluate the present state of African human trypanosomiasis in this region of Benin; this appraisal has been tried from a clinic and serologic survey during May 1986 in the the population of four localities of this province: N'Dahonta, Porga Forêt, Porga Village and Dassari.

Adolescent↗
PubMed1988

[Early auditory evoked potentials in normal sheep and in sheep with trypanosomiasis].

In human and animal clinics, the early auditory potential has been used for a long time in the detection of lesions through the internal auditory way in the cerebral trunk. The aim of this work tries to determine if this non invasive test is apt to show up and to follow the evolution of lesions at the level of auditory way in the cerebral trunk of sheep with trypanosomiasis. According to the human technic, the list of the early auditory potential was realized against ten healthy sheep and ten sheep with trypanosomiasis (Trypanosoma brucei brucei) at the nervous phase. No significant anomalies exist in the sheep with trypanosomiasis. The results are discussed.

Animals↗
PubMed1988

[Treatment of experimental trypanosomiasis caused by Trypanosoma brucei brucei in sheep: study of the minimum active dose of melarsoprol].

Trypanosoma brucei brucei experimentally infected sheep with central nervous system involvement were treated with melarsoprol (Arsobal, Specia, France). The purpose was to determine minimum efficiency concentrations of this drug. Eight sheep divided in four groups of two animals were treated intravenously for 3 days with the following respective dosages: 1.8, 0.9, 0.45 and 0.225 mg/kg/d. After a year of observation, efficient dosages were 1.8 and 0.9 mg/kg/d. The experimentation suggests the possibility to reduce usually given dosages in man.

Animals↗
PubMed1988

[Treatment of experimental trypanosomiasis of sheep caused by Trypanosoma brucei brucei: efficacy of Ro 15-0216 (a 2-nitroimidazole derivative)].

An experiment was carried out on treatment of Trypanosoma brucei brucei experimentally infected sheep with central nervous system involvement with a 2-nitroimidazole derivative: Ro 15-0216 (Hoffmann La Roche & Co Ltd, Basel, Switzerland). After a single intramuscularly or intravenously administration (25 or 50 mg/kg) of this compound in healthy sheep, levels of more than 1 microgram/ml corresponding to trypanocidal concentrations are detected in both blood and cerebrospinal fluid. However, because of short half life, two or three injections a day appeared to be necessary. Six infected sheep were treated by daily intravenous injection for six days: three animals with 25 mg/kg/d and three others with 50 mg/kg/d. Animals which relapsed received 50 mg/kg/d divided in three intravenous injections a day for six days. After a year of observation, all the animals were considered clinically and biologically cured.

Acetanilides↗
PubMed1988

[The fatty acids of Trypanosoma brucei brucei. A comparative study with those of T. b. rhodesiense and T. b. gambiense].

Total lipid extracts from Trypanosoma brucei brucei (T.b.b.), Trypanosoma brucei gambiense (T.b.g.) and Trypanosoma brucei rhodesiense (T.b.r.) were hydrolyzed and the liberated fatty acids were methylated before analysis by gas-liquid chromatography on capillary columns. The sums of the percentages for fatty acids from the different series were compared and the following relationships for the different trypanosomes obtained: --saturated fatty acids T.b.b. greater than T.b.g. greater than T.b.r., --oleic series (omega 9) T.b.g. = T.b.r. greater than T.b.b., --linoleic series (omega 6) T.b.r. greater than T.b.g. greater than T.b.b., --linolenic series (omega 3) T.b.g. greater than T.b.b. greater than T.b.r.

Animals↗
PubMed1988

[Trial of pentamidine in the treatment of trypanosomiasis of sheep inoculated with Trypanosoma brucei brucei].

An experimental study was carried out using 5 Trypanosoma brucei brucei subcutaneously infected sheep. Pentamidine treatment appeared in the CSF. Two animals were injected daily for 10 days and they died with drug intoxication. Two animals received drug every 3 days for 15 days: one of them died, the other was cured after 3 weeks of set-back. This preliminary study should be completed by experimentation made over a more important period of time.

Amidines↗
PubMed1988

[A neuro-epidemiologic survey in a Limousin town].

One characteristic of the Limousin district is the raised average age of its population. Given the growing average age found in France and the ensuing potential problems, it was thought useful to undertake a neuro-epidemiological study of the distribution of neurological diseases in this region. The initial step involved checking the techniques to be used and the form of questionnaire relevant to this type of study. Following W.H.O. recommendations, the total population of one small town was surveyed, and the distribution of various neurological ailments was thus measured (headaches, migraine, cluster headaches: 12.73 p. 100, transient ischemic attack: 1.89 p. 100, stroke: 1.36 p. 100, epilepsy: 1.68 p. 100. Parkinson's disease 1.47 p. 100, dementia: 0.31 p. 100, misc: 0.84 p. 100). These figures were compared with the results from similar pilot projects carried out elsewhere around the world. The results obtained in this preliminary study enabled us to perfect the methods, and to perform a more extensive survey of a representative cross section of the Limousin population. This larger study will be published later.

Adolescent↗
PubMed1988

[Motor evoked potentials. Technic and results in the normal subject].

The transcranial stimulation of the motor cortex and spinal cord was introduced in clinical neurology by Merton and Morton (1980). This reproducible and non invasive technique gives the possibility to elicit unilaterally or bilaterally evoked motor potentials. It is possible to define a Total Conduction Time (TCT) from cortex to muscle and a Peripheral Conduction Time (PCT) from spinal cord to muscle. The central conduction time is given by the latency difference between TCT and PCT. This delay represents the duration of the descending corticospinal volley plus the delay necessary to depolarize spinal motor neurons. For central pathways supplying the upper limbs TCT is 4.3 milliseconds and for central pathways supplying the lower limbs TCT is 9.3 milliseconds. This technique of central motorpathway assessment can be used to define the magnitude of a central motor deficit in neurological diseases affecting the corticospinal tract, during surgical procedures involving the spinal cord and in comatose patients. The new magnetic stimulation is painless and will probably widen the utilization of this method.

Electric Conductivity↗
PubMed1987

Central motor conduction in motor neuron disease.

Central motor conduction was assessed in 13 patients with motor neuron disease and in 15 control subjects. All patients with motor neuron disease, even those without clinical pyramidal signs, had slowed central motor conduction, and in some the delays were asymmetrical. Evoked motor potentials represent a new and reliable method to detect physiological abnormalities of central motor pathways early in the course of motor neuron disease.

Action Potentials↗
PubMed1987

Oligodendroglial pathology in canine distemper virus infection in vitro.

Dog brain cell cultures were infected with different canine distemper virus (CDV) strains to study the oligodendrocytes, which were characterized with eight different antibodies to cover the whole oligodendroglial population in the culture. A few weeks after infection all oligodendroglial cell types started to degenerate and disappeared from the culture. However, since no CDV protein could be demonstrated in the degenerating oligodendrocytes with extensive double-labelling studies, this lesion can not be explained as being a result of cytolytic infection. This conclusion was further supported in experiments with plaque-forming CDV, in which viral replication is restricted to the cytolytic areas only; oligodendrocytes also degenerated in virus-free areas between the plaques. The hypothesis of toxic factors released by other infected cell types in the culture leading to secondary damage of the oligodendrocyte could not be confirmed by transferring supernatants from infected to normal cultures. Whereas the presence of toxic factors can not be completely excluded, the possibility of an abortive infection of the oligodendrocytes with no or very limited viral protein synthesis is discussed.

Animals↗
PubMed1987

Tick bite meningoradiculitis. Ten cases.

A study was undertaken on 10 cases of meningoradiculitis following a tick bite. All patients developed neurologic manifestations and C.S.F. abnormalities. Electrophysiologic studies demonstrated decreased motor potential amplitude and normal motor conduction velocity suggesting distal axonal involvement. Radicular lesions were suspected due to the presence of delayed F waves. This is the first study to confirm these electrical findings by histologic examination of the superficial peroneal nerve of the leg during the course of thick meningoradiculitis.

Aged↗
PubMed1987

Amiodarone is more efficient than verapamil in reversing resistance to anthracyclines in tumour cells.

We have previously demonstrated that amiodarone is able to reverse resistance of rat colon cancer cells to anthracyclines. We now compare the efficiency of amiodarone to verapamil one, another antiarrhythmic agent used in experimental systems and in clinical trials to enhance the effects of anthracyclines on resistant cancer cells. Amiodarone is more efficient than verapamil when both drugs are used at the same molar concentrations. Desethylamiodarone, the main metabolite of amiodarone, is as efficient as its precursor. Optimal concentrations of amiodarone are obtained without side effects in the sera of patients treated by oral administration followed by a loading infusion of amiodarone. On the other hand, maximal tolerated levels of verapamil reported in clinical trials are less efficient than amiodarone maximal levels in the reversal of resistance to anthracyclines in our experimental model in vitro. We suggest that amiodarone, which is more efficient and less toxic than verapamil, could be substituted for verapamil in future clinical trials.

Adenocarcinoma↗