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Biomedical subjects

M Weller

Publications and source records attributed to M Weller.

At least 19 recordsLinked to original sources
PubMed1992

Niacinamide blocks 3-acetylpyridine toxicity of cerebellar granule cells in vitro.

3-Acetylpyridine (3AP) is a potent neurotoxin when administered to laboratory animals. However, its neurotoxic effects have not been investigated extensively in vitro. Cultured cerebellar granule cells are killed by concentrations of 3AP of 0.1-1 mM (ED50 = 220 microM) but not by its 2-acetyl and 4-acetyl analogues. The toxicity of 3AP is enhanced by preexposure to subtoxic concentrations of N-methyl-D-aspartate (NMDA) and is unaffected by the NMDA receptor antagonists MK-801 or APV, as well as by deprenyl, mazindol, or tetrahydrofolic acid. However, 3AP toxicity is completely blocked by preincubating cerebellar granule cells with low concentrations of niacinamide. These data lead us to suggest that 3AP toxicity is due to the substitution of 3AP for niacinamide in the formation of niacinamide adenine dinucleotides (NAD(P)).

2-Amino-5-phosphonovalerate↗
PubMed1992

Tumor cell dissemination triggers an intrathecal immune response in neoplastic meningitis.

The intrathecal immune response in neoplastic meningitis (NM) was studied by quantitation of immune parameters such as immunoglobulin G (IgG); IgM; interleukins (IL) 1, 2, 4, and 6; soluble IL-2 receptors (sIL-2R); interferon gamma (IFNy); tumor necrosis factor-alpha (TNF alpha); and three tumor markers, carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), and fibronectin (FN), in 47 paired cerebrospinal fluid (CSF) and serum samples from patients with NM from different carcinomas, malignant melanoma, and lymphoma. Elevated IgG and IgM indices, CSF oligoclonal Ig bands, and CSF IL-6 indicated an intrathecal immune activation in most patients with NM. Results for IL-1, IL-2, and IL-4 were always negative. sIL-2R and IFNy were detected occasionally but not associated with specific malignant neoplasms. CSF TNF alpha was detected only in NM from cases of malignant melanoma. None of the immune parameters proved useful for the differentiation of NM from autoimmune or inflammatory conditions. Immune parameters were not correlated with tumor markers CEA, AFP, or FN. Results for AFP were positive only in a case of glioblastoma. CEA was a useful and specific diagnostic parameter in carcinomatous NM. CSF FN levels frequently were elevated but are not specific for NM.

Breast Neoplasms↗
PubMed1992

Tonic pupil, areflexia, and segmental anhidrosis: two additional cases of Ross syndrome and review of the literature.

Two patients are described with the triad of tonic pupil, hyporeflexia and segmental anhidrosis (Ross syndrome). Only 18 cases of this syndrome have been reported in the literature so far. While tonic pupil and reduced sweating can be attributed to the affection of postganglionic cholinergic parasympathetic and sympathetic fibres projecting to the iris and sweat glands, respectively, the pathogenesis of diminished or lost tendon jerks remains obscure. To identify the characteristic clinical features, the previous cases of Ross syndrome are reviewed. Recent evidence of subclinical disturbances of sweating in most patients with Adie's syndrome, i.e. tonic pupil and areflexia, casts doubt on the nosological concept of Ross syndrome as a distinct clinical entity.

Adult↗
PubMed1992

Ganglioside antibodies: a lack of diagnostic specificity and clinical utility?

Serum IgG and IgM antibodies to gangliosides GM1, GM2, GM3, AGM1, GD1a, GD1b and GT1b were determined in 210 patients with different degenerative and inflammatory disorders including motor neuron diseases, peripheral radiculopathies and neuropathies, multiple sclerosis and neuroborreliosis. No single disorder was associated specifically with ganglioside antibodies. No characteristic patterns of ganglioside antibodies were observed in any disease category. However, 32% of all patients had pathological antibody titres to at least one ganglioside. Four patients had pathological IgG and IgM titres for all gangliosides evaluated. They suffered from systemic lupus erythematosus [2], neuroborreliosis and schizophrenia, respectively. The results of this study indicate that the introduction of ganglioside antibody determination as a differential diagnostic test in clinical neurology is only helpful in a few patients with typical lower motor neuron syndromes.

Biomarkers↗
PubMed1992

MRI white matter hyperintensity in neuroleptic malignant syndrome (NMS)--a clue to pathogenesis?

The case of a young female patient with neuroleptic malignant syndrome (NMS) and extended MRI white matter hyperintensity in the left parietal and both occipital lobes is reported. MRI lesions resembled findings in hypertensive encephalopathy, they were not readily compatible with CNS vasculitis. Venous sinus thrombosis could be ruled out. Vascular encephalopathy with transient white matter edema and a small residual left parietal lesion is suggested. Neurochemical implications are discussed with particular reference to a possible involvement of excitatory amino acids in NMS pathogenesis.

Adult↗
PubMed1992

Automatic-voluntary dissociation: an unusual facial paresis in a patient with probable multiple sclerosis.

A patient with multiple sclerosis is described who presented with a unilateral loss of voluntary function of his lower face muscles. However, in an emotional situation, there was strong involuntary innervation of these muscles: automatic-voluntary dissociation. The subcortical afferents to the facial motor nucleus are discussed. It is hypothesized that cortical disinhibition of midbrain nuclei underlies the accentuated involuntary innervation.

Adult↗
PubMed1992

Are CSF or serum ganglioside antibodies related to peripheral nerve demyelination in neuroborreliosis, Guillain-Barré syndrome, or chronic inflammatory demyelinating polyradiculoneuropathy?

Cerebrospinal fluid (CSF) and serum IgG and IgM antibodies to seven gangliosides were determined in patients with neuroborreliosis (NB) (n = 20), Guillain-Barré syndrome (GBS) (n = 13), and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) (n = 10). The incidence of elevated antibodies was highest in NB and lowest in CIDP. Correlation between CSF and serum antibodies was only observed for IgG antibodies to GM1, GD1b and GT1b in GBS. The strong IgM antibody reactivity to gangliosides in the CSF of NB patients may be involved in the variety of neurological disorders attributed to Borrelia burgdorferi infection. Since one CIDP and three GBS patients had serologic evidence of prior or concurrent borrelia infection, this infection may belong to the infections that can trigger GBS or CIDP. The lack of specific ganglioside antibody patterns in these four patients suggests that ganglioside antibodies are not the link between Borrelia burgdorferi infection and the demyelination of peripheral nerves in GBS and CIDP.

Adult↗
PubMed1992

Influence of gangliosides on experimental allergic neuritis.

The development of myelin-induced experimental allergic neuritis (EAN) in Lewis rats can be depressed and delayed by adding a ganglioside mixture (GM1, GD1a, GD1b, GT1b) to the immunization compound; however, gangliosides may enhance the induction of adjuvant arthritis. Antibodies against multiple gangliosides are produced in rats after immunization with gangliosides after addition of myelin, but only low titers can be detected in animals immunized with myelin and complete Freund's adjuvant alone. We conclude that this antibody production is not the result of peripheral nerve inflammation but depends rather from external applied gangliosides.

Animals↗
PubMed1992

A rationale for NMDA receptor antagonist therapy of the neuroleptic malignant syndrome.

The triad of rigidity, fever, and elevation of serum creatine phosphokinase (CPK) levels, labeled 'neuroleptic malignant syndrome' (NMS), is a dangerous complication of neuroleptic drug treatment. Amantadine was introduced for the pharmacological management of NMS because of its beneficial effects in Parkinson's disease which were attributed to direct or indirect dopaminomimetic properties of amantadine. While the dopaminomimetic effects of amantadine are weak under experimental conditions, recent studies have confirmed that amantadine is an antagonist at the N-methyl-D-aspartate (NMDA) type of glutamate receptor. Two lines of evidence suggest that amantadine or other NMDA receptor antagonists could be effective drugs for the reversal of NMS symptoms. First, glutamate antagonists restore the balance between glutamatergic and dopaminergic systems when dopaminergic transmission has been antagonized by neuroleptic drugs. Second, by virtue of their effects against rigor and spasticity, NMDA antagonists may reduce increased muscle tone and prevent rhabdomyolysis. In conclusion, NMS may be considered an iatrogenic excitatory aminoacid syndrome which is amenable to NMDA receptor antagonist therapy.

Amantadine↗
PubMed1992

Electroconvulsive therapy in a geriatric patient with multiple bone fractures and generalized plasmocytoma.

Electroconvulsive therapy (ECT) is a highly effective treatment for patients with severe major depressive disorder. ECT can safely be administered even to medically ill, high-risk patients; we report on the complete remission of depressive psychopathology following five unilateral ECT treatments in a suicidal geriatric patient with concurrent prior venous thrombosis, coronary heart disease, multiple myeloma, glaucoma, bilateral petrous bone fractures, and a femoral neck fracture. Most medical complications during ECT can be managed with interdisciplinary cooperation.

Aged↗
PubMed1992

[Electroconvulsive therapy--sources of error and aids in insufficient duration of convulsions].

Modern electroconvulsive therapy (ECT) involves the administration of six to ten convulsions of sufficient duration (25 seconds) by unilateral electrical stimulation of the non-dominant hemisphere. Missed or abortive seizures are a common clinical problem but may often be accounted for by concurrent medication and technical problems with unilateral ECT seizure induction. In the absence of such factors, controlled hyperventilation and intravenous caffeine are adjunctive means to achieve an adequate unilateral ECT treatment course.

Caffeine↗
PubMed1992

Immunological abnormalities in the tears of multiple sclerosis patients.

IgG and IgM concentrations in tears of multiple sclerosis patients (n = 38) are increased compared to normal controls (n = 23). The occurrence of oligoclonal tear IgG bands (7.9%)--as determined by immunoblotting--did not differ between groups. Our findings suggest an altered reactivity of the secretory immune system in MS patients, but did not differ from findings in patients with eye affections or wearing hard contact lenses.

Adult↗