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Biomedical subjects

H C Hopf

Publications and source records attributed to H C Hopf.

At least 145 records · Page 8Linked to original sources
PubMed1985

Indications of the occurrence of inflammatory reactions in the clinical improvement phase in multiple sclerosis patients.

In patients with multiple sclerosis (MS) the spontaneous burst activity (BA) of peripheral blood mononuclear cells was related to the clinical course of the disease. In five patients clinical improvement was found while the BA was significantly increased (more than 300% of the controls). During the appearance of new or deteriorating signs and in the period without clinical changes, the BA was not at all or not markedly increased. In two patients without clinical improvement the BA did not reach levels above 300% of the controls. Our findings suggest that inflammatory reactions represented by the BA occur in the phase of clinical improvement. Since burst-stimulating activity was found in the serum of MS patients, cytokines produced by activated immuno-competent cells are assumed to cause the increased BA. A possible role of prednisone and ACTH on the BA of peripheral mononuclear leucocytes is discussed.

Adrenocorticotropic Hormone↗
PubMed1985

Isometric muscle contraction in endocrine myopathies.

Isometric contraction of the adductor pollicis muscle of the thumb was evoked by stimulating the ulnar nerve in 20 normal adults and 58 patients with endocrine disorders. We evaluated mechanical latency, electromechanical latency, contraction time, half relaxation time, isometric twitch force, compound muscle action potential, nerve conduction velocity, and relative refractory period. Mechanical characteristics were altered in diseases of the pituitary, thyroid, and parathyroid glands. The close relationship between thyroid hormone and contractile properties discriminated between hypo- and hyperthyroidism.

Adrenal Gland Diseases↗
PubMed1985

[Brain abscess in a bidirectional atrial septal defect in adulthood].

An abscess of the brain is a serious complication in patients with congenital heart malformation. The great majority of cases are limited to cyanotic congenital heart disease and a peak in the age distribution can be seen in childhood. We report on a 40-year-old man with progressive right hemiparesis due to an abscess in the left basal ganglia. Clinical aspects and additional diagnostic assessment are described. By cardiologic examination including transoesophageal cross-sectional echocardiography a bidirectional sinus-venosus defect could be detected. This finding supported the diagnosis of a so-called 'paradoxical' brain abscess.

Adult↗
PubMed1984

Changes in the number of complement-binding leucocytes in the peripheral blood of multiple sclerosis (MS) patients: indication to a reduction of EAC3bi-binding T cells in the early acute phase of MS.

Peripheral blood leucocytes (PBL) of multiple sclerosis (MS) patients and healthy controls were examined for their reactivity with EAC3b, EAC3b-beta 1H, and EAC3bi intermediates and C3b- or beta 1H-coated microspheres (ms). A marked decrease was found in the number of EAC3b-beta 1H (P = 0.04) and EAC3bi (P = 0.03) rosettes accompanied with a decrease in the number of total T cells (P = 0.0015), when MS patients were examined within the first 14 days after occurrence of disturbances. On the other hand, when MS patients were examined later than 14 days after onset of disturbances or those with a progressive course were examined, EAC3b-beta 1H (P = 0.0002) and EAC3bi (P = 0.0002) rosettes were markedly increased. In studies where fluorescence-activated cell sorter (FACS) analysis was applied on C3b- and beta 1H-coated ms, similar results were obtained as found with EAC intermediates. Based on previous findings these results strongly suggest that the decrease in EAC3b-beta 1H, EAC3bi, and beta 1H-ms-binding PBL was predominantly due to a loss of beta 1H-binding T cells. A possible relevance of this finding to the demyelinating mechanism(s) is discussed.

B-Lymphocytes↗
PubMed1983

Electrical stimulation of regenerating nerve and its effect on motor recovery.

The rate of recovery of motor function, after axonotmesis of the motor nerve innervating the soleus muscle in the rabbit, was evaluated. In a chronic study over a period of 4 weeks, contraction parameters and muscle action potentials were recorded. A group of rabbits, whose soleus nerves were stimulated with 4 pps for 24 h daily, was compared with a control group. The electrically stimulated animals showed a faster improvement in motor function and reached their initial values a week earlier than the controls. Electrical stimulation proved to have a positive effect on the regeneration and motor recovery of nerves.

Animals↗
PubMed1983

Two cases of adynamia episodica hereditaria: in vitro investigation of muscle cell membrane and contraction parameters.

Membrane potentials, current-voltage relationships, and contractile parameters were studied in intact muscle cell bundles obtained from two patients with adynamia episodica hereditaria. In a normal extracellular medium, the cell membranes had resting potentials of about -80 mV and their current-voltage relationships were not significantly different from control curves. In contrast to normal muscles the afflicted cells were paralyzed in a medium having 6-10 mmol/liter potassium. The mechanisms of paralysis in the two specimens were different from each other. Many fibers from one patient were spontaneously active even in normal solution. In high potassium solution spontaneous activity was increased and the cells gradually depolarized to values at which excitatory sodium current is normally inactivated. This depolarization was connected with an increased sodium conductance and was reversed by the application of tetrodotoxin (TTX). The fibers from the other patient were not spontaneously active. In high potassium solution they were paralyzed at membrane potential values at which normal fibers would still contract. The reason for this paralysis was a reduced excitability.

Adolescent↗
PubMed1983

Wave I of early auditory evoked potentials in multiple sclerosis.

Early auditory evoked potentials (EAEPs) were recorded in a series of 71 consecutively examined patients suffering from clinically definite or probable multiple sclerosis (MS). Wave I abnormalities, i.e., delayed latency, with or without reduced amplitude, were observed in 15 such patients and were interpreted as due to MS in 8 of them. As EAEP wave I is identical with the potential N1 in electrocochleography and corresponds to activity of the most distal part of the acoustic nerve or the spiral ganglion, it is concluded that the peripheral part of the acoustic nerve is involved in about 10% of MS patients. In two cases normalization of initially delayed wave I latencies were demonstrated during follow-up recording. The pattern of a late wave I but normal hearing in 3 patients is interpreted in terms of a desynchronized compound nerve activity with fully preserved conductivity, segmental demyelination of a considerable number of acoustic nerve fibres being the most likely cause.

Auditory Perception↗
PubMed1983

Multiple sclerosis patients show an increased spontaneous activity of their peripheral blood monocytes as measured by chemiluminescence.

I has been reported that myelin basic protein (BP) reacts extremely sensitively to peroxide, which is formed when monocytes/macrophages are stimulated to produce a "respiratory burst" (RB). We measured the RB activity by means of chemiluminescence in peripheral blood monocytes/macrophages (MO) of 17 MS patients, 5 patients with a viral infection of the CNS, and 14 control persons. The median of the spontaneous RB activity of MS patients compared with the median of our control group showed a highly significant increase (P = 0.0002). All MS patients examined possessed a clearly increased MO activity. The highest values, however, were found in MS patients in a bout (means = 315%, means = 296%). Since a viral infection is discussed as being involved in the pathogenesis of MS, we also examined patients with a viral infection of the CNS, but this group of patients did not show a significant increase (P = 0.34). Our data indicate that MO in MS patients generate and/or secrete an increased amount of unspecific mediators of inflammation. The possibility is discussed that this altered MO function might be caused by an altered reaction of MO in MS patients to a viral infection or superinfection.

Central Nervous System Diseases↗
PubMed1982

Changes in the blink responses to combined trigeminal, acoustic and visual repetitive stimulation, studied in the human subject.

Habituation of blink reflexes as measured by amplitude decrement in the orbicularis oculi EMG was examined in 9 human subjects using combinations of repetitive electric stimuli to the bridge of the nose (trigeminal stim.), short clicks (acoustic stim.), and flashes (visual stim.). With trains of paired stimuli, both homogeneous and mixed, habituation was increased when the two stimuli were separated by 250 msec but was decreased when the interval was 30 (50) msec, as compared to single stimulus trains of identical repetition rate. Following acoustic or visual prehabituation the habituation to trigeminal stimuli was enhanced. This "transfer of habituation' was also obtained with acoustic before visual stimuli and vice versa. Regarding dishabituation, interposition of single extrastimuli, for example visual or acoustic within repeated trigeminal stimulation, was more effective than a simple pause by omitting one electric pulse. The results suggest the existence of a pool of interneurones that is that the common final relay for the blink relfex afferents from the trigeminal, acoustic and visual input.

Acoustic Stimulation↗
PubMed1982

Hemifacial spasm: location of the lesion by electrophysiological means.

In hemifacial spasm a late abnormal motor response was elicited by the antidromic volley after stimulating a peripheral branch of the facial nerve. The site of the lesion was calculated from the latency of that motor response and the conduction velocity. In 5 patients the distance was long, and corresponded with a tumor or a vascular anomaly at the cerebellopontine region in 3 of them. An artery sling entering the internal acoustic meatus was found in 2 out of 3 patients with short distances. It is concluded that hemifacial spasm results from a nerve lesion that may be located as far peripherally as the internal acoustic meatus. The theory of facial nuclear irritation is incompatible with such a peripheral lesion.

Cerebellopontine Angle↗
PubMed1981

Influence of artificial blood contamination of the analysis of cerebrospinal fluid.

The influence of artificial blood contamination on the quantitative values obtained in the routine examination of the CSF was investigated. On the basis of dilution series from CSF and blood, the correlation between the number of added erythrocytes and the results of leukocyte counts, protein, glucose and IgG estimation was studied. In addition, the influence of the time between CSF sampling and investigation on erythrocytes and leukocytes, IgG, glucose, pH value and ammonia content in CSF contaminated with blood was investigated. The following data relevant to routine examinations resulted: there are linear correlations between the number of erythrocytes artificially added to the CSF and the leukocyte count, the total protein and the IgG content, whereas glucose is unaffected by the artificial admixture of blood. With regard to the time between sampling and investigation of the CSF, it was shown that the IgG values in blood-contaminated and blood-free CSF do not change. A correct IgG estimation is hence possible even several days after lumbar puncture. The cell count decreases exponentially with time, whereas the total protein rises with progressive cytolysis. The glucose values decrease both in native and in artificially blood-contaminated CSF, whereas the pH values rise rapidly, evidently due to release of ammonia and primary amines from the proteins and amino acids present in the CSF.

Ammonia↗
PubMed1981

[Cerebral disturbances following isolated whiplash injury (author's transl)].

During the last decades, possible sequelae of so-called whiplash-injuries have been intensively explored and described by traumatologists and orthopedists. In regard of the neurological symptoms radicular lesions, impairments of the autonomic nervous system at the neck and spinal cord injuries are well known and accepted. Symptoms of cerebral disturbances (e.g. headache, dizziness, disability of concentrating, abnormal irritability and fatigability) often still are considered as "psychoneurotic". In contrast to this opinion, some experimental and clinical neurophysiological research has shown in the meantime, that there may be cerebral damage even in the presence of a normal clinical examination. At first we want to give a review of this findings, then we derive as a consequence for the clinical practice, that in the future all patients should not only be examined neurologically, but the following investigations should also be done: electroencephalography (EEG), otorhinolaryngological examination (with caloric testing of the labyrinth function) and if possible electronystagmography (ENG) and auditory evoked brainstem potentials (AEP).

Brain Injuries↗
PubMed1981

[Mechanomyography - results in a normal population and in patients with thyroid dysfunction (author's transl)].

Isometric contraction of the adductor pollicis by stimulating the ulnar nerve was determined in 20 normal adult subjects. We measured mechanical latency, electro-mechanical latency, contraction time, time to half relaxation and isometric twitch force. Besides that we registered the compound muscle action potential and the nerve conduction velocity. The median nerve was used to elicit the nerve action potential and to determine conduction velocity and relative refractory period. In 6 pat. with hypothyroidism and in 7 pat. with hyperthyroidism the above mentioned parameters were measured. There was a significant change concerning contractile properties, i.e. muscular contraction became slower in hypothyroidism and faster in hyperthyroidism as compared to values obtained in the control group. The isometric twitch force was reduced in both conditions. To assure the close relationship between thyroid hormone (L-thyroxin) and muscle contraction a group of patients who have undergone thyroidectomy was investigated in the same way. Muscle and nerve parameters were determined during a levothyroxin-therapy and in a period without any treatment. The same phenomenon was observed, i.e. reduction of twitch velocity in the hypothyroid state. The twitch force was not reduced in this group. The close relationship between thyroid hormone and contractile properties allows a discrimination between hypo-and hyperthyroid state and a control of thyroxin substitution.

Electric Stimulation↗
PubMed1980

[Central nervous system damage after decompression accidents (author's transl)].

An increasing number of decompression accidents can be observed due to increasing popularity of diving and due to ignorance of its dangers. Permanent neurological damage is a frequent consequence of insufficient availability of treatment at the site of the accident. A 39-year-old man with a decompression accident showed the broad neurological symptomatology caused by multitopic lesions of the central nervous system. Apart from well known spinal symptoms manifold cerebral manifestations occurred. Mental and in particular neuropsychological defects could be observed beyond the purely neurological symptomatology.

Brain Diseases↗
PubMed1980

The location by early auditory evoked potentials (EAEP) of acoustic nerve and brainstem demyelination in multiple sclerosis (MS).

Tone pips of suprathreshold intensities elicit an acoustic nerve response (I) and six low amplitude brainstem potentials (II-VII) during the initial 10 ms. Seven waves were studied in 40 control subjects and 5 waves (I-V) in 47 patients with MS. The results suggest involvement of the auditory pathway of 24 of 27 patients in the clinically "definite", of 5 of 9 cases in the "probable" and in none of 5 patients in the "possible" MS groups. EAEPs were normal in 6 cases with a spinal form with one exception where changes of potential were indicative of a midbrain lesion. Dysfunction within the acoustic pathway was observed at the level of the acoustic nerve and in the medulla oblongata, pons and midbrain. The significance of the bilateral EAEP abnormalities found in some patients at different levels is discussed with regard to a polytopic location of the underlying lesion.

Adult↗