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Biomedical subjects

L Rumbach

Publications and source records attributed to L Rumbach.

At least 91 records · Page 5Linked to original sources
PubMed1984

[A genetic form of petit mal absence in Wistar rats].

One-third of the Wistar rats bred in the Centre of Neurochemistry in Strasbourg, France, develop spontaneous epileptic seizures which from their clinical manifestations, pharmacological responses, and electroencephalographic findings are suggestive of Petit Mal absences. These fits are genetically determined since in two lines selected from affected animals they occurred in 90 p. cent of three generations. The selection of a pure strain should assist in the use of this pharmacologic and neurophysiologic model of Petit Mal epilepsy.

Animals↗
PubMed1984

[Renal glutamine metabolism in man during treatment with sodium valproate].

The administration of 1500 mg sodium valproate to 20 patients provoked in the kidney an increased glutamine uptake correlated with an increased ammonia release, as shown by the changes of the renal arterial-venous concentration differences of glutamine and ammonia. VPA's action on the renal cell may perhaps constitute a valid model for elucidating the effects of this drug on neurons.

Adult↗
PubMed1983

Sodium valproate-induced hyperammonemia in the rat: role of the kidney.

The intravenous injection of sodium valproate (VPA) 200 mg/kg provoked in fasting rats a 100% increase in the arterial NH+4 concentration by the 10th min. The increase persisted at this level for at least 100 min. Simultaneous measurements of NH+4 and glutamine concentrations in the carotid artery, renal vein and suprahepatic vein showed that there were increases in the release of NH+4 and the uptake of glutamine by the kidney while the [NH+4] of suprahepatic venous blood remained stable. In binephrectomized rats injected with VPA, NH+4 levels did not change. These results suggest that the VPA-induced arterial hyperammonemia depended on the accelerated catabolism or possibly the reduced synthesis of glutamine by the kidneys. The liver of fasting rats does not seem to play a preponderant role in the VPA-induced hyperammonemia.

Ammonia↗
PubMed1983

[Sodium valproate: a hyperammonemic drug. Study in the epileptic and healthy volunteer].

Sodium valproate (VPA) consistently induces an arterial hyperammonemia in epileptics tolerant of this drug and in normal subjects. The hyperammonemia appears with the first oral or intravenous dose of the drug, 15-25 mg/kg, and is established within minutes following drug absorption. In 20 epileptics treated with VPA alone for 4 days, the mean arterial ammonemia measured 2-3 h after breakfast and the day's first VPA dose was 72 +/- 9 mumols/l in non-alcoholics, and 77 +/- 7 mumols/l in alcoholics. Hyperammonemia persisted during chronic treatment; in 10 epileptics who had had received only VPA for over a month, the mean hyperammonemia was 87 +/- 6 mumols/l (normal value means +/- 2 SD = 28 +/- 12 mumols/l). The ammonemia varied in the course of the day; sharp peaks 7 or more times the base value were observed. These variations, differing among subjects, depended on the VPA plasma concentration, and above all on the meal composition and the relative timing of the meal and the drug administration. No secondary effects were seen; in particular, hepatic and pancreatic tests were normal. The hyperammonemia would seem to be due to physiopathological mechanisms other than those giving rise to the hepatic complications occasionally observed with VPA. The permanence and the extent of the hyperammonemia raise questions as to its origin, its relation to the stuporous states induced by VPA, and its eventual repercussions on the functioning of neurons.

Ammonia↗
PubMed1983

Sodium valproate associated with phenobarbital: effects on ammonia metabolism in humans.

Treatment with sodium valproate (VPA) in association with phenobarbital (PB) is accompanied by a greater systemic hyperammonemia than treatment by VPA alone. The anatomical origins of this difference were studied by injecting a dose of 1,500 mg VPA i.v. into six unmedicated patients and six epileptics chronically treated with PB and measuring the ammonium (NH4+) concentration difference between arterial blood and renal, hepatic, internal jugular, and femoral venous blood. In unmedicated patients, arterial [NH4+] rose moderately, secondary to an increased amount of NH4+ released into the general circulation by the kidney; the hepatic metabolism of NH4+ remained normal. In epileptics treated with PB, arterial [NH4+] rose massively, partly as a result of the increased NH4+ release by the kidney and partly because of disturbance of the hepatic metabolism of NH4+. These results provide a clearer understanding of the potentiation of the secondary effects of VPA by PB.

Adult↗
PubMed1983

The renal origin of sodium valproate-induced hyperammonemia in fasting humans.

Acute administration of 1,500 mg of sodium valproate or chronic administration of 30 mg/kg/24 hours induced a more than twofold increase of renal ammoniagenesis in fasting subjects. Hyperammonemia was moderate, as normal hepatic ammonia detoxification persisted. Renal uptake of glutamine increased simultaneously.

Adult↗
PubMed1983

[Hyperthermia with acute rhabdomyolysis in a psychotic treated with neuroleptics].

A 36 year old psychotic man receiving treatment with slow-release pipotiazine and trihexyphenidyl developed nine days after addition of droperidol signs suggestive of a malignant neuroleptic syndrome: altered general condition, diffuse hypertonia, akinesia, fever and vomiting. Results of biologic tests and a muscle biopsy were suggestive of a severe rhabdomyolysis. Cessation of neuroleptic therapy and the administrative of nifedipine brought a gradual return return to normal conditions, and progressively increasing doses of neuroleptic could be given without complications 12 days later. Onset of hyperthermia during neuroleptic treatment raises two questions: 1) is the etiology related to a malignant neuroleptic syndrome or acute catatonia, or a heat stroke? 2) to what extent are neuroleptics responsible for these disorders?

Adult↗
PubMed1983

[Anomalies in fatty acids distribution and superoxide dismutase activity in lymphocytes of an adult with atypical ceroid lipofuscinosis].

A 27-year-old Algerian patient presented a slowly progressive disease clinically characterized by a cerebellar syndrome, absence of deep reflexes, bilateral sign of Babinski, deep sensory disturbances, ophthalmologic disorders and pes cavus. The diagnosis of ceroid lipofuscinosis resulted from the presence of lipofuscin deposits evidenced as autofluorescent bodies, and a particular type of curvilinear, crystalloid ultrastructural inclusion bodies in muscle, lymphocytes and liver. Biochemical tests showed reduction in levels of linoleic and arachidonic acids, and of superoxide dismutase activity in lymphocytes. These findings suggest that the biochemical anomalies result from disturbances in polyunsaturated fatty acids metabolism. These results can be related to pathogenetic hypotheses for ceroid lipofuscinosis suggesting a predominant role for peroxidation of fatty acids.

Adult↗
PubMed1983

[Role of hyperammonemia in stuporous states induced by sodium valproate].

Stuporous states induced by sodium valproate (VPA) are accompanied by an isolated marked hyperammonemia. In reality, hyperammonemia occurs after administration of VPA even in the absence of neurological complications. The hyperammonemia is of purely renal origin and results from modifications in glutamine metabolism, this compound being the main precursor of amino acid neurotransmitters. Combined administration of VPA and phenobarbitone increases the level of hyperammonemia due to lack of detoxification by the liver of the excess of ammonia produced by the kidneys. The anatomical site of origin of the ammoniogenesis, and its intensity, were studied in two patients with a history of stuporous states during combined VPA-phenobarbitone treatment. A single injection of VPA at a later date when they were being treated by combined phenobarbitone-carbamazepine therapy, induced disturbances in ammonia metabolism which did not differ qualitatively from those observed when intolerance to VPA is lacking. It is therefore not possible to rely on simple biological tests to detect patients at risk. Correlation is also lacking between the degree of hyperammonemia and disorders of vigilance. Ammonia does not therefore appear to be the only factor responsible for neurological complications and the role of other factors must be investigated. These include: disturbances of metabolism of inhibitory and excitatory aminoacid neurotransmitters, the condition of the cerebral parenchyma, and the excitatory effect of sodium valproate which could act to varying degrees in synergy with the hyperammonemia to provoke a stuporous state.

Adult↗
PubMed1983

[Polymyositis associated with Gougerot-Sjögren syndrome].

A 42-year-old woman with a sicca syndrome associating xerostomia and xerophthalmia developed proximal motor weakness in all four limbs due to a polymyositis. Regression of the motor deficiency followed the administration of corticoid therapy. Polymyositis occurring during the course of Gougerot-Sjögren disease should be treated as a separate entity requiring specific therapy.

Adult↗
PubMed1982

Spontaneous paroxysmal electroclinical patterns in rat: a model of generalized non-convulsive epilepsy.

During quiet wakefulness of 63 adult Wistar rats, 24 exhibited synchronous paroxysmal bursts consisting of spikes and spike and wave discharges, recorded in the amygdala and frontoparietal cortex. Discharges were associated with a sudden immobility of the rat and rhythmic twitches of vibrissae or cervicofacial musculature. As soon as the phenomena stopped, the animal resumed its previous behavior. Paroxysmal electroclinical attacks could be observed as long as the animal survived. Similar electrical discharges have been observed previously in rodents by other authors and interpreted as an epileptic phenomenon. Preliminary pharmacological results confirm this interpretation and emphasize the similarity between our findings and the human petit mal epilepsy.

Animals↗
PubMed1982

Lymphocytotoxic and monocytotoxic antibodies in the serum and cerebrospinal fluid of multiple sclerosis patients.

Serum cold cytotoxic antibodies (CA), detected at 15 degrees C using a microcytotoxicity technique, were present in 12 of 21 multiple sclerosis (MS) patients, weak or absent in 6 neurological patients without MS and present but weak in 5 out of 32 healthy controls. In MS, these cold CA were directed against 3 distinct cellular populations: total lymphocytes, B lymphocytes and monocytes; certain antibody tests were positive at 37 degrees C; no correlation between CA and clinical disease was observed. Cerebrospinal fluid (CSF) antibody levels were high in both MS and non-MS patients and at 37 degrees C produced lysis of monocytes in the absence of complement. These antibodies may be normal CSF constituents. Our results suggest that there may be 3 different antibodies and that they may play a role in immunomodulation, especially in MS.

Adolescent↗
PubMed1982

Artifactual increases in the concentration of free GABA in samples of human cerebrospinal fluid are due to degradation of homocarnosine.

Samples of untreated human cerebrospinal fluid (CSF) were kept at room temperature (20 +/- 1 degree C) up to 72 h, and changes in gamma-aminobutyric acid (GABA) and homocarnosine contents were measured. The concentration of free GABA increased with time, and concomitantly a similar decrease occurred in the concentration of homocarnosine. Total GABA after hydrolysis (present in human CSF at concentrations of 40-100 times that of free GABA) did not change. After 2 h the increase in CSF GABA for seven subjects ranged from 42 to 244 pmol/ml. The rate of increase in CSF GABA was positively correlated with the initial homocarnosine concentration. Approximately 5% per h of the initial homocarnosine content was degraded during the first 7 h at room temperature; thereafter the rate gradually decreased. No free GABA was formed in CSF frozen at -70 degrees C for 10 days. When this CSF was restored to room temperature, the formation of free GABA from homocarnosine occurred at essentially the same rate as that observed in fresh CSF. These results demonstrate that the well-known artifactual increase in GABA concentration of untreated human CSF depends on the concentration of homocarnosine. The rapidity of this increase (up to 2 pmol/ml/min) could account for disparities among CSF free GABA concentrations previously reported from normal subjects. It is suggested that measurement of concentrations of total GABA in the CSF would provide a better index of human brain GABA concentration than determination of CSF free GABA.

Carnosine↗
PubMed1982

Stuporous episodes during treatment with sodium valproate: report of seven cases.

Of 13 patients with complex partial seizures who experienced stuporous states during treatment with sodium valproate (VPA), 4 received VPA only, 4 VPA and phenobarbital (PB) and 5 VPA, PB, and a third anticonvulsant. Seven cases were described in detail. Side effects-stupor or confusion-appeared a few days after efficacious drug plasma levels were attained, persisted until therapy was readjusted, and disappeared 24 to 72 h after VPA withdrawal. Therapeutic trials established the role of VPA in the onset of stuporous states. The adverse effects of VPA were potentiated by the concomitant administration of other anticonvulsants. Stupor was not due to VPA overdoses, and plasma concentration of the drugs were not correlated with the electroclinical signs. The EEG showed spike and wave discharges or continuous sharp theta and delta waves persisting during VPA treatment. The fact that all 13 stuporous, VPA-treated patients were subjected to partial seizures with complex symptomatology, and none were cases of generalized epilepsy, together with the observations that the disturbances of consciousness started with focal symptoms and EEG signs resembling those of spontaneously occurring partial seizures, suggest that VPA given alone or in association with other antiepileptics has a paradoxical epileptogenic effect in certain forms of epilepsy.

Anticonvulsants↗
PubMed1982

[Familial presenile dementia: Gerstmann-Sträussler-Scheinker's syndrome (author's transl)].

A similar affection has developed in eight members from four generations of a family living in the Alsace. The disease is characterized by the onset of a pyramidal, pseudobulbar syndrome and dementia during the third or fourth decade of life. The outcome is fatal after a mean period of three years. Cerebral biopsies in three cases have demonstrated multicentric amyloid plaques differing from senile plaques. Clinical and pathological findings are similar to those currently reported in the literature as being typical of Gerstmann-Sträussler-Scheinker's syndrome. The affection appears as a separate entity: the multicentric plaques, clinical symptomatology, pyramidal or pseudobulbar, cerebellar syndromes, usually preceding dementia, age of onset, course, and familial character or the disorder distinguish it among presenile dementias. Its clinical profile and course are very similar to that of familial cases of Alzheimer's disease, some of which are probably cases of Gerstmann-Strässler-Scheinker's syndrome. Transmission to animals, though inconstant, places it within the group of transmissible dementias among kuru, Creutzfeldt-Jakob's, and familial forms of Alzheimer's disease. The familial nature of the affection and the variability of clinical and pathological features in the same family illustrate the complex relationships between hosts and pathogenic agents in the clinicopathological expression of a disease.

Adult↗