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Biomedical subjects

M E Kornhuber

Publications and source records attributed to M E Kornhuber.

At least 19 recordsLinked to original sources
PubMed2006

[Eagle's syndrome: a rare cause of facial pain and difficulties in swallowing].

A 47-year-old patient suffered from right-sided facial pain in the chin and lower cheek, hyperpathia, and difficulties in swallowing. The diagnosis of Eagle's syndrome was based on digital palpation of the bilaterally elongated styloid process and radiography. Eagle's syndrome should be considered in patients with difficulty swallowing, masticatory pain, globus sensation, and neuropathic pharyngeal or facial pain. If conservative therapy fails, selected patients may benefit from surgical excision of elongated styloid processes if pain relief by local anesthesia is proven.

Deglutition Disorders↗
PubMed2005

[Differential influence of immune therapy on relapses and progression in multiple sclerosis: interpretation and therapeutic consequences].

It is well established that relapses can be suppressed by different substances in patients with relapsing-remitting multiple sclerosis (MS). In contrast, patients with progressive forms of MS do hardly respond to immune therapy. Therefore, start of immune therapy after the first relapse has been proposed, especially in order to prevent degeneration and disability. This view is challenged in the present review. Actually no evidence exists in support of a retardation or an attenuation of secondary progression by early immune therapy. Widespread degeneration occurs early and progresses independently from inflammatory plaques. Therefore, autoimmunity per se is no adequate paradigm to explain MS-pathogenesis entirely. A virus/superantigen-dualism is proposed to explain the different parts of MS, instead. It is concluded that evidence-based immune therapy should be adapted to the actual inflammatory activity of the disease. A suitable parameter for this purpose is the interval between 2 relapses.

Disease Progression↗
PubMed2001

Length dependence of variables associated with temporal dispersion in human motor nerves.

Temporal dispersion in motor nerves is associated with changes of amplitude, area, duration, and Fourier spectra of compound muscle action potentials (CMAPs) when comparing responses to proximal and distal stimulation. These changes depend on the length of the nerve segment. To quantitatively assess this dependence, motor conduction studies of nerve segments of various lengths were performed in the median, ulnar, and tibial nerves of 86 test subjects, aged 4 to 73 years. Amplitude, area, duration, and spectral energy above 49 Hz of CMAPs were measured. Values after distal and proximal stimulation of each nerve segment were compared to determine amplitude decay, area decay, protraction, and high-frequency attenuation. A significant length dependence of amplitude decay was found in the tibial and ulnar nerves, of area decay in the median and ulnar nerves, and of CMAP duration in the ulnar and tibial nerves. The length dependence of the high-frequency attenuation was significant in all nerves studied. This report provides normative data for variables associated with temporal dispersion.

Action Potentials↗
PubMed1999

Multiple A waves in Guillain-Barré syndrome.

In 13 of 14 patients with Guillain-Barré syndrome (GBS), we observed multiple A waves in at least one limb nerve on routine electroneurographic studies within 7 days after onset of symptoms. The patient without A waves had a severe axonal type of GBS with tetraplegia and almost complete loss of M responses following electrical stimulation of limb nerves. In the remaining 13 patients, on average 8 +/- 2 (mean +/- SD) A waves were present in each tibial nerve (n = 24) and 4 +/- 1 A waves in each peroneal nerve (n = 26). About half of the A waves were below 50 microV in amplitude, whereas amplitudes were higher than 120 microV in only 22 of 299 A waves. Of these A waves, 68 were not constantly elicitable. There was a significant correlation between the number of A waves up to 50 ms poststimulus and the reduction in amplitude of the compound muscle action potential when elicited with proximal compared to distal stimulation in the peroneal (n = 26, P < 0.0005; Kendall's tau) and tibial nerves (n = 24, P < 0.002). Therefore, in GBS both conduction block and A waves are presumably signs of inflammatory nerve lesions. The existence of multiple A waves soon after onset of symptoms seems to be a sensitive sign of GBS.

Adolescent↗
PubMed1996

Blood-CSF barrier integrity in multiple sclerosis.

INTRODUCTION: In about 20% of MS patients an increased CSF/serum albumin quotient (QAlb) has been observed. The reason for this blood-CSF barrier dysfunction is yet unclear. SUBJECTS AND METHODS: QAlb values from 48 MS patients in relapse were correlated with parameters of active CNS lesions as measured by gadolinium-DTPA MRIs. QAlb values from 20 MS patients without relapse served as controls. RESULTS: Mean QAlb values (x 10(3) of a group with spinal cord lesions (7.6 +/- 3.6; n = 16) differed significantly from those of a control group (4.6 +/- 1.5; n = 20; p < 0.005) as well as from those of a group with supratentorial lesions (5.0 +/- 1.8; n = 18; p < 0.05), and were higher than those of a group with infratentorial lesions (5.8 +/- 2.8; n = 14). QAlb values of patients with a spinal lesion tended to decrease with increasing time intervals between onset of relapse and lumbar puncture. CONCLUSION: The data is in consent with the present knowledge on flow dynamics of both extracellular fluid and CSF. As a clinical consequence, increased QAlb values in MS patients may hint at an active spinal or, less likely, infratentorial lesion.

Adult↗
PubMed1993

L-glutamate and L-aspartate concentrations in the developing and aging human putamen tissue.

We have previously reported that the developmental regulation of NMDA receptor expression in human brain is characterized by a sharp postnatal increase peaking at about age 1 year. We have now extended this work by measuring concentrations of L-glutamate and L-aspartate in the putamen from 45 human autopsy specimens. Both amino acids increased steeply within the first postnatal year after which they remained fairly constant throughout life. There was no impact on glutamate and aspartate levels in putamen of sex, side of the brain, postmortem time and storage time of brain tissue.

Adolescent↗
PubMed1991

Stability of human blood serum aminoacids after storage at different pH and temperature conditions.

The stability of the aminoacids in human blood serum ultrafiltrates and in an aminoacid standard solution was investigated under different pH and storage conditions. At close to neutral pH values the aminoacid concentrations remained constant for at least 12 months at -50 degrees C (n = 6), except for lysine. With acid but particularly with alkaline conditions a time- and temperature-dependent decrease was observed for glutamine and asparagine with concomitant increases of glutamate and aspartate. Similar, but less prominent alterations were noted for the concentrations of methionine, glycine, tyrosine, histidine, arginine and ornithine. Almost independent of pH, there was an effect of temperature; after 24 h at 55 degrees C a significant increase of several per cent in a number of serum aminoacid concentrations was observed, presumably due to the hydrolysis of small proteins and peptides. For the purpose of aminoacid analysis it is recommended that samples be stored deproteinized, deep-frozen and at neutral pH.

Adult↗
PubMed1989

[3H]MK-801 binding sites in post-mortem human frontal cortex.

The binding of [3H]MK-801 ((+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate) was investigated in extensively washed homogenates of post-mortem human frontal cortex. The association of [3H]MK-801 proceeded slowly (t1/2 = 553 min) and reached equilibrium only after a prolonged incubation (greater than 24 h). The dissociation of [3H]MK-801 from the binding site was also slow (t1/2 = 244 min). Glutamate, glycine and magnesium markedly increased the rate of association (t1/2 = 14.8 min) and dissociation (t1/2 = 36.5 min). At equilibrium, the binding was not altered by these substances. Specific binding was linear with protein concentration, was saturable, reversible, stereoselective, heat-labile and was nearly absent in the white matter. Scatchard analysis of the saturation curves obtained at equilibrium indicated that there was a high-affinity (Kd1 1.39 +/- 0.21 nM, Bmax1 0.483 +/- 0.084 pmol/mg protein) and a low-affinity (Kd2 116.25 +/- 50.79 nM, Bmax2 3.251 +/- 0.991 pmol/mg protein) binding site. All competition curves obtained with (+)-MK-801, (-)-MK-801, phencyclidine and ketamine had Hill coefficients of less than unity and were best explained by a two-site model. Thus, our results demonstrate the presence of binding sites for MK-801 in post-mortem human brains and provide evidence for binding site heterogeneity. Furthermore, glutamate, glycine and magnesium accelerate the association and dissociation of [3H]MK-801 to and from its binding sites. The results add support to the hypothesis that MK-801, glutamate, glycine and magnesium all bind to different sites on the NMDA receptor-ion channel complex.

Adult↗
PubMed1987

Phencyclidine depresses transmitter release at the neuromuscular synapse of the locust.

The presynaptic effects of phencyclidine (PCP) were studied in the locust extensor tibiae muscle. The neurally evoked transmitter release is diminished in the presence of 5 x 10(-6) to 5 x 10(-5) M PCP. This is indicated (1) by an increased coefficient of variation of the excitatory junction potentials; (2) by an increased rate of failures (a) with nerve stimulation in low [Ca2+]saline and (b) with focal extracellular stimulation in normal [Ca2+]saline. The rate of spontaneous transmitter release is not affected.

Animals↗
PubMed1987

Alcohol consumption and blood-cerebrospinal fluid barrier dysfunction in man.

The cerebrospinal fluid (CSF)/serum albumin ratio has been used a marker for blood CSF barrier permeability in 116 normal patients. We attempted to correlate the CSF/serum albumin ratio with a number of clinically measurable parameters including alcohol consumption. Alcohol consumption had a significant effect on the blood-CSF barrier. Our data indicate that alcohol increases blood CSF barrier permeability in a dose-dependent manner. The measured values of parameters indirectly indicative of alcohol consumption, such as gamma-glutamyltranspeptidase (gamma-GT) and erythrocyte mean corpuscular volume (MCV), were also correlated with enhanced blood-CSF barrier permeability. Although an apparent influence of age, body weight and sex on blood-CSF barrier permeability was observed, these correlations were not separable from the effect of alcohol consumption.

Adolescent↗
PubMed1986

Positive correlation between contamination by blood and amino acid levels in cerebrospinal fluid of the rat.

The degree of contamination by blood in macroscopically clear cerebrospinal fluid (CSF) from the rat was assessed by the red blood cell count. Amino acid concentrations in the same samples were determined using high performance liquid chromatography. A significant positive correlation between the number of erythrocytes and amino acid concentration was found for alanine, asparagine, aspartate, citrulline, glutamate, glycine, phenylalanine and taurine but not for glutamine, histidine, isoleucine, leucine, lysine, methionine, ornithine, serine, threonine, tyrosine and valine. The difference in amino acid concentration between samples that were or were not contaminated by blood was as much as one order of magnitude for aspartate, glutamate, glycine and taurine; the concentrations of these amino acids were highly correlated with the erythrocyte counts (r = 0.87, P = 0.000002 for glutamate). The results suggest that macroscopical inspection is often not sufficient to judge contamination by blood in the CSF.

Amino Acids↗
PubMed1986

Diphenylhydantoin (DPH) blocks HIV-receptor on T-lymphocyte surface.

Previous reports have shown the capacity of diphenylhydantoin (DPH) to attach to the membranes of lymphatic cells as a hapten and thus exert an unspecific influence on their ability to express certain recognition molecules. This led us to the hypothesis, that DPH might as well serve to manipulate the t-helper-lymphocytes in a way that the mode of infection of these cells by the HIV might be blocked. In order to verify this hypothesis, we exposed normal control lymphocytes as well as lymphocytes from DPH-treated patients (3 X 100-150 mg DPH/day, Phenhydan, for a minimum of 10 days) to radioactively labeled HIV (125I). Remaining radioactivity was assessed using a gamma-counter and measured 64.000-92.000 counts/min (n = 24, mean 80.000) for the control lymphocytes, while remaining radioactivity for the DPH-treated lymphocytes ranged between 2000 and 7000 counts/min (n = 24, mean 4.000, p less than 0.001). These results and similar experiments obtained with FITC-labeled HIV led us to the conclusion that DPH inhibits HIV recognition of T-lymphocytes and therefore might be used in therapy and prophylaxis of AIDS.

Cells, Cultured↗