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Biomedical subjects

L Rumbach

Publications and source records attributed to L Rumbach.

At least 55 records · Page 3Linked to original sources
PubMed1994

Vertebral-artery dissection following a judo session: a case report.

A few days after a judo session, an 11-year-old boy presented with an ischemic stroke with dizziness, aphasia and ataxia. CCT scan revealed a left thalamic infarct. Angiography showed a fibromuscular dysplasia (FMD) of the left vertebral artery probably complicated by dissection. Subsequent evolution was favorable. This observation points out the fact that the association of a cervical pain with neurological signs of vertebrobasilar stroke, especially occurring after a cervical trauma or rotatory motion, should alert to the possibility of vertebral-artery dissection. The diagnosis is mainly based on angiographic criteria. Accurate diagnosis has implications for prognosis and probably for acute medical treatment.

Aortic Dissection↗
PubMed1993

Treatment of multiple sclerosis with anti-CD4 monoclonal antibody. A preliminary report on B-F5 in 21 patients.

Twenty-one patients with definite active multiple sclerosis (MS) were treated with a monoclonal anti-T CD4/B-F5 (murine IgG1) antibody for 10 days. Side effects were observed in 11 patients during the first infusion. These side effects were accompanied by and probably related to a transient increase in IL6 and TNF alpha serum levels. This problem led to treatment interruption in one patient. Neither clinical improvement nor deterioration was observed in the course of treatment. EDSS improvement (> 1 point) occurred in six patients one month post-treatment. One month after the end of treatment total lymphocytes and CD3+ and CD4+ cells were significantly decreased. Cytokine analysis performed in serum and in CSF before and after treatment showed no induced modifications. Ten patients developed xenogenic antibodies. It is of interest that the patients with relapsing-remitting forms were relapse-free at the 6th month post-therapy.

Adult↗
PubMed1993

Event-related potentials in Parkinson's disease: a 12-month follow-up study.

Auditory event-related potentials were recorded using the oddball paradigm in 26 patients with Parkinson's disease, all treated with L-Dopa. The latency of the P3 wave was significantly greater than in an age-matched controls, and was also correlated with the disease duration, but not with scores on two scales measuring cognitive deficit. One year later, when treatment with a dopaminergic agonist, bromocriptine 20-30 mg/day, had been added to the therapeutic regimen, N2 and P3 latencies had increased, whereas several clinical parameters had improved. Thus a longer P3 latency does not seem to be linked to a global cognitive deficit. The use of neuropsychological tests exploring more limited tasks should show the prospective utility of event-related potentials in Parkinson's disease.

Adult↗
PubMed1993

Quantitative cerebral magnetic resonance imaging during ACTH treatment of multiple sclerosis.

Serial MR scans were performed with the 2DFT imaging method and the filtered backprojection imaging method on 12 patients with multiple sclerosis in acute phase, 4 in a relapsing/remitting form, and 8 in a progressive form, before, during and after ACTH treatment. Both T1 and T2mono relaxation times, obtained by fitting transverse magnetization decay curves with a monoexponential function within the apparently normal white matter and the areas of increased signal, were measured. With the backprojection method it was possible to fit the transverse magnetization decay curve with a biexponential function and obtain T2long and T2short relaxation times. The T2mono and T1 relaxation times of the apparently normal white matter were significantly different from those obtained for volunteers, but no significant differences were found before, during, or after treatment. The transverse magnetization decay curves of the areas of increased signal were better fitted by a biexponential function. No significant changes in these relaxation times were observed after ACTH treatment. These results argue against an anti-oedematous action of ACTH and may suggest that it has an immunosuppressant effect.

Adrenocorticotropic Hormone↗
PubMed1991

Nuclear magnetic resonance T2 relaxation times in multiple sclerosis.

An original method was used to carry out the mathematical analysis of T2 transverse magnetization decay curves and the measure of T2 relaxation times on multiple sclerosis (MS) patients. The presumably normal white matter (WM) of these patients presented higher T2 relaxation times (98.6 msec), in comparison with that found in a population sample (88 msec). In this case, magnetization decay curves remain mostly monoexponential and are characterized by a single T2. On the other hand, areas of increased signal (AIS) curves are always better fitted by a biexponential function characterized by a short (82 msec) and a long (greater than 200 msec) T2. The spreading out of long T2 varies from one AIS to another in the same patient and among different patients; values of long T2 also vary with time, but without any correlation with the clinical state. In fact, no correlation was been established between relaxation times and clinical parameters. Quantitative MRI therefore enables a different approach to interpret MRI images; results suggest that several histobiochemical parameters play a role in the pathogenesis of an AIS and that MS is a dynamic and constantly evolving disease.

Adult↗
PubMed1991

In vivo determination of multiexponential T2 relaxation in the brain of patients with multiple sclerosis.

In vivo measurement of T2 relaxation times in multiple sclerosis (MS) lesions by magnetic resonance imaging (MRI) is potentially useful for the evaluation of the disease activity. Seven patients with definite MS were investigated over a period of three years (19 examinations), using a whole-body MRI scanner operating at 0.15 T with a specially designed high-power radio-frequency head coil. A modified CPMG sequence with a 180 degree pulse interval of TE = 6 msec and 128 echoes was used for the T2 relaxation measurement of the areas of increased signal (AIS) and white matter (WM). A biexponential T2 analysis of each pixel of the spin-echo images was computed. The T2 relaxation processes were found to be a monoexponential function in WM. The T2 relaxation times of apparently normal white matter in MS patients was significantly longer than in control subjects. The T2 relaxation curves of the AIS were found in most cases to fit a biexponential function characterized by a short and a long T2. T2 long relaxation times of AIS were spread out over a wide range (150-560 msec). The study of T2 long histograms shows that some AIS can be divided into two or three parts depending on the T2 long values. Each of these parts may correspond to a pathological process such as edema, demyelination and gliosis. Evolution of T2 relaxation times over a period of time cannot as yet be correlated with modifications in the clinical state.

Adult↗
PubMed1990

Antibodies to cerebellar soluble lectin CSL in multiple sclerosis.

Cerebrospinal fluid samples from 239 patients with various neurological disorders were tested for the presence of autoantibodies to an endogenous mannose-binding protein, the cerebellar soluble lectin CSL, by means of an immunoblotting test with rat CSL as antigen. 47 of 51 patients with multiple sclerosis were positive for anti-CSL compared with 30 of 188 patients with other neurological disorders. 14 of the 30 false-positive patients were over 60 years old, an age group not typical of multiple sclerosis patients. The specificity of the test for multiple sclerosis was 85% and the sensitivity 93.5%. The possibility that CSL is an important immunological target in multiple sclerosis allows new insights into the possible causes and development of this disorder.

Adult↗
PubMed1990

[Magnetic resonance imaging after a one-month interval of lesions of multiple sclerosis in 2 populations, one during an acute attack treated with methylprednisolone, the other stable with no treatment].

Changes in clinical symptoms and MRI lesions of multiple sclerosis (MS) were evaluated on two occasions, one month apart, in 30 patients. Seventeen patients (group 1) with acute exacerbation were treated with methylprednisolone in high, then decreasing doses during a total of 30 days. MRI examinations were performed before and at the end of treatment. The remaining 13 patients (group 2) had been clinically stable for more than 6 months and received no treatment; here again, MRI was performed at 30 days' interval. All patients in group 1 showed functional improvement. The MRI lesions remained stable in 7 of group 1 patients and in 4 of group 2 patients. In the remaining 19 patients (10 in group 1 and 9 in group 2), the number, size and location of MRI lesions were found to have changed over 1 month. There was no correlation between clinical changes and the modification observed at MRI. This study confirms that high-dose corticosteroids are effective, at least clinically, in acute exacerbations, but the main results are that MS is a continually evolving disease, that changes rapidly occur in the lesions observed at MRI and that corticosteroids do not seem to influence the course of MRI lesions. Our study also suggests that MRI is inadequate to evaluate the effectiveness of short-time treatments of MS.

Follow-Up Studies↗
PubMed1990

[Contribution of MRI to the topography of oculomotor disorders in multiple sclerosis].

Magnetic resonance imaging (MRI) was performed in 20 patients with multiple sclerosis and abnormal electro-oculographic examination. All but 2 patients showed MRI abnormalities in the infratentorial region: hypersignal on T2-weighted sequences and/or images of atrophy. Usually, each patient had multiple abnormalities, which could prevent anatomico-oculographic correlations. With oculomotor disorders of cerebellar origin, correlations between clinical findings and MRI images were satisfactory, but with disorders due to brainstem lesions correlations were not so good, as shown by the results in 9 patients with internuclear ophthalmoplegia.

Adult↗
PubMed1989

Valproate-induced hyperammonemia of renal origin. Effects of valproate on glutamine transport in rat kidney mitochondria.

The antiepileptic sodium valproate (VPA) systematically induces an asymptomatic hyperammonemia of renal origin in fasting normal human volunteers and in fasting rats, accompanied by an increased renal glutamine uptake. Fasting rats were injected with VPA and their mitochondria isolated, or isolated mitochondria of fasting rats were incubated with VPA. Transmembranal mitochondrial glutamine uptake and activities for five mitochondrial and three cytosolic enzymes involved in ammoniagenesis were measured. In VPA-incubated mitochondria, glutamine transport increased for VPA concentrations between 10(-3) and 10(-5) M; enzyme activities did not change. In mitochondria of VPA-treated rats, Km and Vmax were unaffected. These findings reflect membrane effects of VPA observed in other experimental settings.

Ammonia↗
PubMed1989

Succinate transport inhibition by valproate in rat renal mitochondria.

Sodium valproate is an antiepileptic drug which may have side effects on different organs. Its mechanism of action, as yet unclear, may involve an effect on membranes. One possibility, an effect on mitochondrial membranes via an inhibition of oxidative phosphorylation, has been studied here by observing the transmembranal transport of a respiratory substrate, succinate, in rat kidney mitochondria incubated with valproate, or from rats injected with valproate. Succinate transport was inhibited in both conditions, which suggests that the effect was probably due to a direct effect of valproate rather than to an action of a valproate metabolite. For the valproate-incubated mitochondria, inhibition, described by a bell-shaped curve, started at a valproate concentration of 10(-7) M and was maximum at valproate 10(-5)M. Valproate's effect on mitochondrial transmembranal succinate transport can be compared to other evidence for membranal actions of valproate, actions which may clarify certain therapeutic or toxic properties of this drug.

Animals↗
PubMed1989

Multiple sclerosis, sleep latencies and HLA antigens.

The role of HLA antigens, and HLA-DR2 in particular, in the determination of mean sleep onset latencies (MSOLs) in multiple sclerosis (MS) was studied. It has been suggested that this antigen may play a part in the reduction of MSOLs, since nearly 100% of patients suffering from narcolepsy are DR2-positive. A multiple sleep latency test was performed in 37 patients suffering from MS without spontaneous complaints of sleep disturbances and who were typed for HLA-A, B, C, DR and DQ. The MSOL was reduced in a total of 21 patients, in only 7 of 15 DR2-positive patients and in 12 of 21 DQw1-positive patients. However, it was reduced in 13 of 16 B8- or B14-positive patients. In contrast with this, in the absence of an early sleep onset (MSOL greater than 30 min), no HLA antigens were found to be over-represented when considered individually; only those patients positive for a group of cross-reacting HLA antigens (B5, B15, B18, B21 or B35) had an MSOL greater than 30 min. These results suggest that the genes which code for the DR2 or DQw1 antigens, which are present in nearly 100% of narcoleptics, are not solely responsible for the appearance of an early sleep onset in MS.

Adult↗
PubMed1988

Multiple sclerosis and corpus callosum atrophy: relationship of MRI findings to clinical data.

Among 110 patients (45 men, 65 women), aged 15 to 66, with clinical and/or biological diagnosis of multiple sclerosis (MS), severe to moderate corpus callosum (CC) atrophy was observed in 67 (60%) patients. Correlation between CC atrophy, brain atrophy, duration and severity of clinical symptoms, and high signal white matter areas, was carried out in 90 patients. Mean age was 46 years for patients with severe CC atrophy, and 33 years for those without atrophy. Mean duration of the disease was 14 years in patients with severe atrophy, and 5 years in patients without atrophy. Severity of clinical symptoms is more pronounced in patients with severe CC atrophy. Numerous or large white matter high signal areas are observed in patients with severe CC atrophy on T2-weighted images. CC atrophy appears earlier than brain atrophy in the course of MS.

Adolescent↗
PubMed1988

Effects of drugs affecting dopaminergic neurotransmission in rats with spontaneous petit mal-like seizures.

Drugs interacting with dopaminergic neurotransmission were studied on a model of genetic petit mal-like seizures in a strain of Wistar rats. Dopamine participates in the control of seizures in this model, as in other models of petit mal or of genetic epilepsy. Mixed dopaminergic D1/D2 agonists: L-DOPA, apomorphine, amphetamine and nomifensine, gave dose-dependent reductions of the duration of spike and wave discharges. Mixed D1/D2 antagonists: haloperidol, flupentixol and pimozide, caused dose-dependent increases of duration of spike and wave discharges. The findings with specific agonists or antagonists of D1 or D2 receptors did not reveal clearly the respective roles of these receptors in controlling the spike and wave discharges. The D2 agonists, lisuride and pergolide, had no effect on spike and wave discharges, except at toxic doses; bromocriptine decreased the duration of the discharges, but without clear-cut dose-dependency. The D2 antagonists: sulpiride and tiapride, had no effect. The D1 agonist SKF 38393 decreased duration of the spike and wave discharges in a dose-dependent manner. The D1 antagonist SCH 23390 had a biphasic effect: increasing the duration of spike and wave discharges at small doses and decreasing it at large doses. These results suggest that the simultaneous stimulation or inhibition of both receptors, D1 and D2, is necessary for influencing spike and wave discharges in this model.

Animals↗
PubMed1988

[Biochemical analysis of the cerebrospinal fluid in multiple sclerosis: study of various formulas].

Multiple sclerosis (MS) is often characterized by a intrathecal synthesis of immunoglobulins (Ig) in cerebrospinal fluid (CSF), which may be evaluated in several ways: ratio methods (IgG index, Schuller's or Tourtelotte's formulae) or demonstration of an oligoclonal distribution, or both. In a retrospective study, 256 CSF analyses were evaluated. The 4 parameters studied were disturbed in about the same proportions in each of the 3 MS subgroups of Mac Alpine's classification. An oligoclonal distribution is more rarely present in pathologies other than MS. None of these tests is specific for the diagnosis of MS. Haptoglobin index variations do not distinguish between the different groups of patients. From a physiopathological point of view, however, they may perhaps reveal an acute local inflammatory reaction, different from the immune reaction giving rise to the Ig synthesis.

Adult↗
PubMed1988

[Magnetic resonance imaging and herpetic encephalitis].

Cerebral lesions in two cases of herpetic encephalitis were detected by MRI using a spin-echo sequence and delayed echo signal recordings, whereas CT scans were normal. In one case pathology showed lesions to be more extensive than MRI anomalies. This suggests that even in the absence of EEG and CT anomalies, an encephalitis can be suggested by MRI.

Electroencephalography↗
PubMed1987

Effects of drugs affecting noradrenergic neurotransmission in rats with spontaneous petit mal-like seizures.

Wistar rats of a strain displaying spontaneous petit mal-like seizures and spike-wave EEG discharged (SWD) were injected i.p. with drugs affecting noradrenergic neurotransmission. The EEG and behavior were recorded. Drugs which decrease alpha-noradrenergic neurotransmission, prazosin (alpha 1-antagonist) and clonidine (alpha 2-agonist), increased SWD and were sedative in a dose-dependent manner. Drugs which increase alpha-noradrenergic neurotransmission, ST 587, cirazoline (alpha 1-agonists) and yohimbine (alpha 2-antagonist), reduced SWD and the latter two caused agitation. Drugs which interact with beta-noradrenergic transmission (salbutamol, isoprenaline and propranolol), monoamine oxidase inhibitors (nialamide and iproniazid), and a noradrenaline reuptake inhibitor (desipramine), did not affect SWD. These findings suggest that noradrenaline participates in the control of petit mal-like seizures in the rat, as in other types of seizures and other animal models.

Animals↗