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Biomedical subjects

G Ebinger

Publications and source records attributed to G Ebinger.

At least 145 records · Page 8Linked to original sources

Epinephrine and norepinephrine stimulation of adenylate cyclase in bovine retina homogenate: evidence for interaction with the dopamine D1 receptor.

Dopamine, epinephrine and norepinephrine provoke dose-dependent stimulation of adenylate cyclase activity in bovine retina homogenates. The stimulatory effect of all three compounds is inhibited by the D1 antagonist SCH 23390 and, in a stereoselective manner by the cis-isomer of flupenthixol. The D2 antagonist haloperidol and alpha-and beta-adrenergic antagonists failed to block the catecholamine stimulation. These results evidence that, in bovine retina, not only dopamine but also epinephrine and norepinephrine interact with dopamine D1 receptors that are stimulatory coupled to an adenylate cyclase system.

Adenylyl Cyclases↗

Lymphocytic meningoradiculitis (Garin-Bujadoux Bannwarth): from syndrome to disease?

In two children with lymphocytic meningoradiculitis (Bannwarth's syndrome), IgG and IgM antibodies to Borrelia burgdorferi were demonstrated. Clinical and laboratory parameters of the syndrome are described and recent bacteriological and serological findings that link the syndrome to the American Lyme disease are discussed, as well as the effects of antibiotic treatment.

Animals↗

Brain stem infarction as a complication of giant-cell arteritis.

Two cases of brain stem infarction as an early and fatal complication of giant-cell arteritis are reported. These complications occurred despite adequate treatment with corticosteroids. The findings at autopsy are compared with those of the literature. The possible pathogenetic mechanisms of vertebro basilar occlusion and the therapeutical implications are discussed.

Aged↗

Intraarterial sodium nitroprusside infusion in the treatment of severe ergotism.

Treatment of migraine with ergot alkaloids may produce systemic vasospasm in patients, especially as a result of automedication and overconsumption but also due to individual hypersensitivity. Peripheral vasoconstriction may lead to gangrene of the extremities, necessitating amputation. Various treatments have been tried against ischemic complications during ergotism with varied and unpredictable results. We report two recent cases of severe acute peripheral ischemia due to ergotamine abuse successfully treated with continuous systemic sodium nitroprusside infusion. The doses used during intraarterial injection are well below those known to be toxic. Consequently, the adverse effects of cyanide toxicity can be avoided. We think that intraarterial infusion of sodium nitroprusside, associated with forced diuresis and the administration of hydroxycobalamin, constitutes the treatment of choice of extreme peripheral ischemia of ergotism.

Adult↗

Periventricular metastases of a primary intracranial alpha-fetoprotein-producing germ cell tumor.

Periventricular subependymal lesions were found on CT scan in a young man with growth failure, diabetes insipidus, mental deterioration, and hypogonadism with delayed puberty. An initial very good response to radiotherapy was followed a few months later by a relapse, presenting as a very large tumor in the base of the frontal lobes. Serum alpha-fetoprotein at the time of the relapse was very elevated suggesting that the tumor was largely composed of an endodermal sinus tumor component, which was confirmed at autopsy. The purpose of this report is to stress the importance of the use of tumor markers in a particular clinical and neuroradiological setting.

Adolescent↗

Determination of the biogenic amines and their major metabolites in single human brain tissue samples using a combined extraction procedure and high-performance liquid chromatography with electrochemical detection.

A combined extraction system for the selective and quantitative isolation of the monoamines norepinephrine, epinephrine, dopamine, serotonin (5-hydroxytryptamine) and their metabolites 3-methoxy-4-hydroxyphenylethylene glycol, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid, homovanillic acid and 3-methoxytyramine from one single brain tissue sample is described. The extraction system is a combination of an ethyl acetate extraction for 3-methoxy-4-hydroxyphenylethylene glycol, 3,4-dihydroxyphenylacetic acid, 5-hydroxyindoleacetic acid and homovanillic acid, and two successive ion-pair extractions. In a first step, the catecholamines are quantitatively isolated by extracting with heptane--octanol (99:1) containing 0.25% tetraoctylammonium bromide as an ion-pairing agent in the presence of 0.2% diphenylborate. In a second step, 3-methoxytyramine and 5-hydroxytryptamine are isolated from the aqueous phase with di(2-ethylhexyl)phosphoric acid as counter-ion in chloroform. Dihydroxybenzylamine, isohomovanillic acid and 5-hydroxy-N-methyltryptamine are used as the internal standards.

Biogenic Amines↗

The use of capillary gas chromatography/mass spectrometry for the determination of acidic dopamine metabolites in human brain.

A capillary gas chromatographic/mass spectrometric method was developed for the determination of homovanillic acid and 3,4-dihydroxyphenylacetic acid in discrete areas of human brain known to contain only small amounts of dopamine metabolites. The electron impact mass spectra of the trimethylsilyl derivatives of homovanillic acid and 3,4-dihydroxyphenylacetic acid and their deuterated isotopic variants were used for their identification and quantification.

3,4-Dihydroxyphenylacetic Acid↗

Reversible "locked-in" syndromes.

Two young patients are described who made good recoveries from a "locked-in" syndrome presumed to be due to ventral pontine ischemia. The first patient recovered completely from quadriplegia and mutism. In the second patient the only permanent sequellae were slight dysarthria and mild spasticity. Since patients may recover nearly completely from a "locked-in" syndrome, aggressive supportive therapy seems justified during the initial weeks or months.

Adult↗

Regional distribution of the dopamine D2 receptors in the mesotelencephalic dopamine neuron system of human brain.

Using the [3H]spiroperidol binding technique, we performed a regional distribution of the D2 receptors in the human mesotelencephalic dopamine neuron system. D2 receptors were found in decreasing order of concentration in caudate nucleus greater than putamen greater than nucleus accumbens greater than globus pallidus greater than amygdala greater than substantia nigra. D2 receptors could not be detected in any cortical region. The nigrostriatal and mesolimbic components of the mesotelencephalic dopamine neuron system are easily to reconstitute. If there exists a mesocortical component in man, its actions appear not to be mediated by D2 receptors.

Aged↗

Unilateral seizures in a patient with hairy cell leukemia treated with interferon.

A patient is described who developed unilateral seizures whilst being treated with recombinant interferon for hairy cell leukemia. Special features included the relatively low dose of interferon, the focal aspect of the epilepsy and the high resistance to anticonvulsants. Oligoclonal banding of cerebrospinal fluid proteins may have resulted from polyclonal activation of bone marrow plasma cells during interferon treatment. Disturbances of consciousness, dysphasia, visual hallucinations, upper motor neuron deficit, tremor, dizziness, numbness, myalgia and headache, all of them neurological complications of interferon treatment, are discussed.

Adult↗

Coma as presenting manifestation of Wernicke's encephalopathy.

A patient in whom coma was the presenting manifestation of Wernicke's encephalopathy is reported. Clinical reports on coma in Wernicke's encephalopathy are scarce, but postmortem studies have demonstrated that this form of presentation is often not recognized. The diagnosis of Wernicke's encephalopathy should be suspected in any patient presenting with coma of unclear etiology.

Coma↗

D2 dopamine receptors in calf globus pallidus: agonist high- and low-affinity sites not regulated by guanine nucleotide.

By use of the radioligand [3H]spiroperidol, D2 3,4-dihydroxyphenylethylamine (dopamine) receptor binding characteristics were studied in calf globus pallidus and compared with those of neostriatum. Antagonist competition curves were monophasic and revealed similar affinities for neostriatum and globus pallidus, suggesting a uniform receptor population with one affinity state for antagonists. In both regions, competition curves with the agonist dopamine were biphasic, distinguishing a high- and low-agonist-affinity state. In neostriatum and globus pallidus, respectively, 45% and 19% of [3H]spiroperidol binding was displaced with high affinity and the remainder with low affinity. In neostriatum, the addition of 0.4 mM GTP resulted in a partial conversion from high- to low-affinity state with a remaining high-affinity component of 15%. In globus pallidus, dopamine binding was not altered by GTP. The capability of GTP to modulate agonist binding to D2 receptors appears to be dependent on their neuroanatomical localization.

Animals↗

Enophthalmos as a rare manifestation of metastatic orbital involvement.

Two cases in which orbital metastasis produced enophthalmos, instead of the usual exophthalmos, are reported. Only fourteen other cases have been described previously and they are reviewed. At time of diagnosis of the enophthalmos, meningeal carcinomatosis coexisted in the first case and probably also in the second case. This association can lead to diagnostic errors with either the orbital metastasis or the meningeal carcinomatosis being missed. In addition, as in our second case, the enophthalmos can be the initial manifestation of cancer.

Adult↗

Lower motor neuron disease in a patient with Hodgkin's disease treated with radiotherapy.

A case of lower motor neuron disease after extended field irradiation for cervical stage IA nodular sclerosing Hodgkin's disease is reported. Recurrence of Hodgkin's disease is excluded and other diagnostic possibilities are discussed. We compared this case with twenty-four similar cases reported in the literature after irradiation of the spinal cord for Hodgkin's disease or other neoplasms. Special features included the relatively advanced age of the patient, the long latency period, a premonitory CK-rise and reversibility. The entity is considered to be a very rare and relatively benign complication of spinal cord irradiation important to recognize as an entity in order to avoid extensive reevaluation.

Electromyography↗