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Biomedical subjects

W Muellbacher

Publications and source records attributed to W Muellbacher.

26 records · Page 2Linked to original sources

Anti-GM1 antibodies in polyneuropathies of unknown origin.

This study was undertaken to determine whether anti-GM1 titres are raised in polyneuropathies of unknown origin and whether determination of these titres is useful for diagnosing these conditions. The study population comprised 20 controls (aged 36-88 years), 12 patients with polyneuropathies of known origin (aged 31-81 years) and 15 patients with polyneuropathies of unknown origin (aged 40-77 years). Antibody levels were measured using a commercial GM1 enzyme linked immunosorbent assay kit (Buehlmann Laboratories). Mean anti-GM1 IgG and IgM antibody titres were not raised in patients with polyneuropathies of unknown origin. Anti-GM1 IgG antibody titres were raised in one and GM1 IgM antibody titres in none of the patients with polyneuropathies of unknown origin. In conclusion, GM1 antibody levels are rarely raised in polyneuropathies of unknown origin and probably play a minor role in the pathogenesis of these conditions.

Adult↗

Yes/yes head tremor without appendicular tremor after bilateral cerebellar infarction.

We report a 67-year-old man who developed yes/yes head tremor without appendicular tremor six weeks after right occipital and bilateral cerebellar infarction. The tremor was resting-postural. Its activity increased with excitement, decreased either after ethanol, lateroflexion or rest and stopped at sleep. Four-vessel angiography revealed a well collateralised occlusion of both vertebral arteries. Needle-EMG recordings showed rhythmic, synchronous agonist/antagonist activity in both the splenius capitis and sternocleidomastoideus muscles at a frequency of 2-3 Hz. After administration of botulinum toxin A (DysportR), the tremor markedly improved and vanished completely after a booster. Since then the tremor did not reappear. Delayed-onset, yes/yes head tremor without appendicular tremor may be caused by bilateral cerebellar infarction and can be successfully relieved with botulinum toxin A.

Botulinum Toxins↗

Prolonged impaired consciousness in basilar artery migraine.

Basilar artery migraine is a distinctive disorder characterized by recurrent occipital headache with typical migrainous phenomena in conjunction with a variety of symptoms referable to a transient dysfunction of the brainstem, the cerebellum and the occipital lobes. Impairment of consciousness is a common feature but is usually too brief to be captured by electroencephalography. Here we report an unusual case of basilar artery migraine with prolonged attacks of impaired consciousness lasting more than two weeks, thus allowing electroencephalographic follow-up. In the acute stage, EEG showed marked generalized slow wave delta activity. After the attack, both the electroencephalographic and clinical findings subsided within the following weeks.

Adult↗

Electrophysiological assessment of central and peripheral motor routes to the lingual muscles.

Compound muscle action potentials (CMAPs) of the lingual muscles were recorded by especially devised bipolar surface electrodes placed on the tongue. Distinct responses were evoked in the tongue muscles by peripheral electrical stimulation of the hypoglossal nerve medial to the angle of the jaw and by transcranial magnetic stimulation of the motor cortex. With cortical stimulation during voluntary activation of the tongue muscles it proved easy to obtain responses with the characteristics of centrally evoked responses allowing reliable measurements of latencies and amplitudes. By contrast, responses from magnetic stimulation of the intracranial segment of the hypoglossal nerve were more difficult to obtain and the reproducibility was often not satisfactory. In a group of 20 healthy subjects the average distal motor latency of both sides from peripheral stimulation was 2.4 ms and the corresponding amplitude was 9.3 mV on the left and 8.6 mV on the right side (range 5.1-16.0 mV). Cortical stimulation gave responses with an average onset latency of 8.6 ms and 8.8 ms and an average amplitude of 1.8 mV and 2.6 mV on the left and right sides of the tongue respectively (range 0.7-5.6 mV). From this mean conduction times of 6.2 ms on the left and 6.4 ms on the right side (SD 1.0 ms) between cortex and mandibular angle and relative amplitudes from cortical stimulation as compared with the peripheral CMAP of 29% on the left and 21% on the right side (range 7%-66%) were calculated. In 16 patients it was possible to differentiate between a central (supranuclear) and a peripheral (intranuclear) site for the lesions of the motors routes to the lingual muscles and to show subclinical lesions in some cases. With a recording arrangement allowing selective unilateral recording of muscle activity from both sides of the tongue the assumed bihemispheric motor representation of the lingual muscles was confirmed.

Action Potentials↗

Regulation of plasminogen activation in isolated perfused rat kidney.

To better understand the mechanism and regulation of plasminogen activation within the kidney, the release and excretion of plasminogen activator activities was studied in the isolated perfused rat kidney in the absence and presence of plasminogen substrate. In the absence of plasminogen, the kidneys released a constant amount of plasminogen activator activity into both the urine and the perfusate. On continuous infusion of purified human plasminogen into the perfusate, the release of plasminogen activator activity into the urine slightly increased, and plasmin generated could be detected in both urine and perfusate. With the use of specific antibodies against the tissue-type (t-PA) and the urokinase-type plasminogen activator (u-PA), respectively, the activity in the perfusate could be identified as t-PA, whereas the activity in the urine could be ascribed to u-PA. A bolus injection of either antibody into the plasminogen-supplemented perfusion medium completely inhibited plasminogen activator activity and generation of plasmin in the vascular or tubular compartment. Furthermore, intrarenal inhibition of t-PA activity by the specific antibody significantly increased the concentration of plasminogen in the perfusate, indicating decreased consumption. This effect was accompanied by increased excretion of u-PA into the urine, suggesting that the availability of intact plasminogen in the renal circulation directly or indirectly might participate in the regulation of u-PA excretion into the urine.

Animals↗