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Biomedical subjects

M Dumas

Publications and source records attributed to M Dumas.

At least 163 records · Page 9Linked to original sources
PubMed1989

Peripheral nerve disorders in Lyme-Borreliosis. Nerve biopsy studies from eight cases.

Clinical, cerebrospinal fluid and nerve biopsy findings from eight patients with peripheral nervous system complications of Lyme-Borreliosis are reported. Five cases showed the typical features of the Garin-Bujadoux-Bannwarth syndrome (meningoradiculoneuritis), one patient had a multiple mononeuritis associated with acrodermatitis chronica atrophicans Herxheimer. Two cases could not be classified under these diagnostic categories. In all patients we observed a prompt relief of signs and symptoms after antibiotic treatment. Nerve biopsy studies showed gross infiltrations of epineurial vasa nervorum and small infiltrations around endoneurial capillaries. The infiltrations consisted of lymphocytes, histiocytes and plasma cells. We did not find necrotizing changes of the vessel walls, but thrombosis and recanalization was observed in some epineurial vessels. Seven biopsies showed a significant loss of myelinated axons due to axonal degeneration. Only in one biopsy did we observe segmental demyelination next to axonal degeneration. We conclude that the PNS complications of Lyme-Borreliosis in early and late stages of the disease are angiopathic due to vasculitis of the vasa nervorum and primarily caused by axonal degeneration.

Acrodermatitis↗
PubMed1989

Motor evoked responses after lumbar spinal stimulation in patients with L5 or S1 radicular involvement.

Motor evoked responses were recorded bilaterally in the tibialis anterior and soleus muscles after lumbar spinal stimulation in 45 patients suffering from L5 or S1 radiculopathies due to disc protrusion, and in 25 healthy controls. A significant prolongation (P less than 0.01) of motor evoked response latency was observed in 72% of the patients with L5 radiculopathy and in 66% of the patients with S1 radiculopathy. These anomalies were observed in patients with objective neurological signs as well as in patients free of objective signs. These findings indicate that subclinical compressive radiculopathy can be detected by this method which represents a useful adjunct in the assessment of radicular pain of discopathic origin.

Adolescent↗
PubMed1989

Different pituitary beta-endorphin and adrenal cortisol response to ethanol in individuals with high and low risk for future development of alcoholism.

The purpose of the present studies was to investigate the activity of the adrenal gland and the pituitary beta-endorphin system in individuals from families with a 3 generation history of alcoholism, High Risk group, or from families without history of alcoholism, Low Risk group. All subjects had a medical examination, a drinking behavior personal interview and the Michigan Alcoholism Screening Test. Individuals with medical problems or excessive drinking were not included in the study. On the day of testing, a blood sample was taken at 9:00 a.m., then the subject drank a placebo drink or an ethanol solution (0.5 g ethanol/kg B.Wt.). Additional blood samples were taken at 15, 45 and 120 minutes post-drink. Results indicated that individuals of the High Risk group had lower basal levels of beta-endorphin like immunoreactivity (beta-EPLIR) than individuals of the Low Risk group. The dose of 0.5 g ethanol/kg B.Wt. induced an increase in the plasma content of beta-EPLIR of the High Risk group, but not of the Low Risk group. In the Low Risk group ethanol did not induce an increase above the 9:00 a.m. levels, however, it attenuated the beta-endorphin decrease overtime, observed following the placebo drink. Analysis of beta-endorphin-like peptides in the plasma of the High Risk group, with Sephadex G-75 chromatography indicated that the major component of the plasma beta-EPLIR was beta-lipotropin. Plasma cortisol levels, following ethanol intake, presented a small increase in the High Risk group but not in the Low Risk group. Both groups presented similar blood alcohol levels. The basal levels of immunoreactive cortisol and beta-endorphin in the plasma of individuals who were alcoholics, but had been abstinent for at least six months prior to testing were similar to the levels of the High Risk group. Thus there are differences both in the basal levels and in the response of the cortisol and the pituitary beta-endorphin system to an acute ethanol challenge between the two groups.

Adult↗
PubMed1989

Central motor conduction and glutamate deshydrogenase: activity in olivo-ponto-cerebellar atrophy.

Central motor conduction was investigated by way of magneto-electric cortico-spinal stimulation in 6 patients with sporadic olivo-ponto-cerebellar atrophy. Two patients were found to have reduced leucocyte GDH activity. Only the 3 patients with corticospinal deficits displayed increased central conduction rates, which were predominant in the lower limbs. The duration of the disease is statistically longer in patients with corticospinal deficit compared to patients with no corticospinal deficit. In OPCA, evoked motor potentials are useful in assessing the corticospinal deficit which does not appear to be linked to reduced leucocyte GDH activity.

Adult↗
PubMed1989

Glutamate dehydrogenase and aspartate aminotransferase in leukocytes of patients with motor neuron disease.

We report the results of glutamate dehydrogenase (GDH) and aspartate aminotransferase (AAT) activities in leukocytes of 24 patients with motor neuron disease (MND) and 20 matched control subjects. In 62.5% of patients suffering from MND, we detected a leukocyte GDH deficiency (+/- 2 SD) as compared with the mean value obtained in controls. By contrast, there was no difference in leukocyte AAT activities in affected and nonaffected subjects. Abnormal cellular glutamate metabolism might be involved in the pathogenesis of MND.

Adult↗
PubMed1989

Participation of the membrane effect to the cytotoxicity of tensio-active agents comparison with ocular irritation in vivo.

A study for the comparison of the action of tensio-active agents have been made with 3 models: The rabbit erythrocyte to evaluate the immediate membrane effect. SIRC fibroblasts (rabbit cornea) to evaluate the toxicity after 3 days. The rabbit eye (Draize). The cellular model have shown that there is a difference between non irritants tensio-active agents, and irritants-very irritants in vivo, except the BRIJ group. To evaluate the part of membrane effect in the interaction tensio-active-cell, it has been realized a test of haemolysis on the rabbit erythrocyte on 10 tensio-active agents. It shows that the cellular model can also determine a different toxicity than the one provoked by an aggression on the plasmic membrane.

Animals↗
PubMed1989

Epidemiological study of neuro-cysticercosis in northern Togo (West Africa).

In april 1987, an epidemiologic study in Northern Togo was carried out in order to evaluate the prevalence of cysticercosis and epilepsy. The survey also aimed to investigate possible connections between these two illnesses. The study encompassed 5264 subjects over 15 years old, selected using random sampling techniques; 125 cases of cysticercosis were diagnosed (2.4% of sample population); 12 by anatomo-pathological examination of cysts 18 (14.4%) based on skull and muscle x-ray calcifications and 104 patients were identified using ELISA tests on 1527 serum samples (optical density greater than or equal to 0.4). Among 88 epileptic patients (prevalence = 16.7 per thousand), 27 also suffered from cysticercosis (38.7% of all epileptic patients, 21.6% of cysticercosis patients and 0.51% of the total population).

Adolescent↗
PubMed1989

Variations of sotalol kinetics in renal insufficiency.

Decreased elimination of sotalol (160 mg) is found in patients with renal insufficiency. Simulation of plasma concentrations at steady-state exhibits moderately higher concentrations when creatinine clearance is between 10 and 30 ml/min and very high plasma concentrations when creatinine clearance is less than 10 ml/min suggesting, if treatment is absolutely necessary, monitoring in these cases and the reduction of the dose in major renal insufficiency.

Arrhythmias, Cardiac↗
PubMed1989

[Epidemiology of amyotrophic lateral sclerosis in the Limousin area].

Several epidemiologic studies of amyotrophic lateral sclerosis have shown a uniform repartition over the world. We report the results of a retrospective study and the preliminary results of a prospective study carried out in the Limousin area. The mean incidence per/year is 0.97/100,000 in the retrospective study and 1.3/100,000 in the prospective study. Such data are similar to those previously reported. The two major findings are the high frequency of bulbar palsy and the high mean age of the patients. This can be associated with the high mean age of the population in the Limousin area as compared to other regions.

Age Factors↗
PubMed1989

[Study of central motor pathways using cortical magnetic stimulation and spinal electrical stimulation: results in 20 normal subjects].

Evoked motor potentials can be elicited by magnetic cortical or electric spinal stimulations. The central conduction time (CCT) corresponds to the difference in latencies between the total conduction time (from cortex to muscle) and the peripheral conduction time (from spinal cord to muscle). CCT is the sum of the conduction time in the cortico-spinal fibers, of the spinal synaptic delay, and of the conduction time in the proximal part of the motor roots. CCT values (mean + standard deviation) were determined in 20 healthy subjects ranging from 21 to 56 years of age (mean 31.2). Results of magnetic cortical stimulation were compared to the results of electrical stimulation of the cortex. CCTs after magnetic cortical stimulation were longer than CCTs after electric cortical stimulation. This could be explained by the fact that electrical stimulation elicits a direct response in the cortico-spinal tract whereas magnetic cortical stimulation has indirect effects on the pyramidal cells of the motor cortex through excitatory interneurons. Compared with electrical stimulation, the magnetic stimulation has the great advantage of being painless and allows a safe evaluation of the central motor pathways in man.

Adult↗
PubMed1988

Decreased density of peripheral benzodiazepine binding sites on platelets of currently drinking, but not abstinent alcoholics.

Using the isoquinoline carboxamide derivative, PK 11195 as selective ligand, the binding properties of peripheral benzodiazepine binding sites were compared on platelets of alcoholics and non-alcoholic, healthy controls. When compared to controls, alcoholics during prolonged ethanol consumption show a significant reduction in the density of platelet [3H]PK 11195 binding sites. However, following abstention from alcohol, the density of these sites is similar to controls. These data suggest that a reduction in the density of peripheral benzodiazepine binding sites on platelets may be a biochemical index of prolonged ethanol use and indicate a possible role for these sites in mediating the chronic effects of alcohol.

Adult↗
PubMed1988

The sheep (Ovis aries) as an experimental model for African trypanosomiasis. I. Clinical study.

Sheep were used as an experimental model to study trypanosomiasis. Twelve animals were infected with Trypanosoma brucei brucei, and the clinical evolution of the disease in the sheep corresponded closely to that described in human patients. The main clinical signs of the experimental infection were hyperthermia, anaemia, loss of weight and behavioural disturbances. Death occurred in all cases after a mean time of 75 days. Trypanosomes were detected in blood films nine to 15 days after inoculation, and the parasitaemia was usually mild and irregular. Changes in the cerebrospinal fluid--increase in leucocyte counts and the presence of trypanosomes--appeared after about 45 days. This model would provide a valuable way of testing the effectiveness of new therapeutic drugs.

Animals↗
PubMed1988

The sheep (Ovis aries) as an experimental model for African trypanosomiasis. II. Biological study.

Sheep that have been experimentally infected with a strain of Trypanosoma brucei brucei reproduce the clinical symptomatology of human African trypanosomiasis. We measured two biochemical parameters which are altered during the infection; total serum and cerebrospinal fluid (CSF) proteins, and the time of appearance and levels of IgM in both serum and CSF. Serum protein levels were considerably raised (up to 90 gl-1), although in CSF the levels were always less than 1 gl-1. The ratio of serum albumin to globulins fell to a value of 0.40 during the course of the disease. Electrophoresis of CSF proteins demonstrated the appearance of polyclonal immunoglobulins. Plasma IgM levels rose to ten times normal values, and after the sixth week IgMs made up 10% of total CSF protein content. Specific antibodies were detected, by both indirect immunofluorescence and an ELISA technique, within two weeks after infection in the blood and after four weeks in the CSF.

Animals↗
PubMed1988

Differential retention of doxorubicin in the organs of two strains of rats.

Fluorescence microscopy and high pressure liquid chromatography were used to study the decrease of doxorubicin (DXR) concentrations in the liver, spleen, heart, lung, kidney and skeletal muscle of two strains of rats at various times after a single intravenous injection of the drug (8 mg kg-1). DXR was located within the cell nucleus and was mostly undegraded, it persisted, especially in heart, lungs and spleen where it was detectable 10 days after injection. The DXR/DNA ratio, was used as an index of nuclear fixation of the drug. A major difference in the DXR/DNA ratio between the two strains were observed in heart and spleen results; the DXR/DNA ratio was significantly higher in heart and spleen compared with lung, liver and kidney in both strains.

Animals↗
PubMed1988

Specific antibody activity against neuroendocrine tissue in a case of POEMS syndrome with IgG gammopathy.

Specific antibody binding activity directed against pituitary tissue was demonstrated in a typical case of POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes) syndrome with paraproteinemia of IgG lambda type. IgG binding against various other tissues could not be detected by immunoelectroblotting and immunocytochemistry. We propose that POEMS syndrome is an antibody-mediated immune disorder, in which the hypophysis is the primary target of the pathologic myeloma antibodies. The immunopathogenetic lesion of the hypophysis could induce secondary disturbances of other organs, thus explaining the multisystemic disorder.

Adult↗