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Biomedical subjects

R Jürgens

Publications and source records attributed to R Jürgens.

46 records · Page 3Linked to original sources
PubMed1980

Somatosensory-evoked potentials and vibration.

Vibratory stimuli (250 Hz) with amplitudes between 50 and 200 microns were delivered to the middle finger knuckle of 15 human subjects. The cortical-evoked potentials and psychophysical magnitude estimations were simultaneously recorded. Only the large, late components of the evoked cortical potentials showed significant correlation to the stimulus intensity. While the psychophysical response showed a slight positive acceleration, the evoked potential stimulus-response relations were slightly nonlinear with negative acceleration. The early components of the evoked potential were well localized over the contralateral, postcentral hand area; the late components showed a wide distribution over both hemispheres. The late, bilateral components resembled the alpha rhythm in frequency and distribution. It is concluded that late components resembling alpha rhythm may be due to stimulus-synchronized oscillations of alpha generators. The underlying neuronal events are probably of less importance for perception. By contrast, the important neuronal activity in the first 100 ms after arrival of the impulses at the cortex does not appear in the scalp-recorded evoked potential.

Adult↗
PubMed1980

[A computer oculographic and electroencephalographic double-blind study including well-being for determining changed vigilance under therapy with tiapride].

Owing to its specific action on the dopaminergic neurons of the corpus striatum, which has been demonstrated in animal experiments. N-[2-(diethylamino)ethyl]-5-(methyl-sulfonyl)-o-anisamide (tiapride, Tiapridex) a recently developed drug from the family of the benzamides, appears to be particularly suited for the treatment of motor disorders resulting from extrapyramidal effects. In a double-blind study, the action of the drug on the vigilance of 16 normal subjects was compared with that of diazepam and a placebo. A minor reduction in vigilance was seen in the EOG and EEG following administration of 100 mg three times daily. However, this effect would not be expected to impair general performance or behaviour in traffic. With regard to self-assessment (existential orientation scale, list of complaints), no change was noted in male individuals receiving tiapride, while female test persons exhibited a slight tendency toward feeling low, though their mood remained above the limits of depression.

Arousal↗
PubMed1977

Pragmatic-semantic and syntactic factors influencing ear differences in dichotic listening.

In a three-factorial experiment sequences of 3 words were presented dichotically. The sequences consisted of two uninflected nouns denoting a person or a group of persons and 1 verb denoting an interaction. The three factors were Ear, Syntactic Structuredness vs. Unstructuredness and Semantic-Pragmatic Structuredness vs. Unstructuredness. The sequences in the syntactic unstructuredness condition are spoken in staccato form without sentence intonation and the order of the 2 nouns and the verb was at random; in the syntactic structuredness condition the sequences were spoken fluently and with sentence intonation and the order was always N-V-N. Semantic-pragmatic structuredness of the sequences means that one of the two potential actor-object-relations between the two nouns of a sequence was more probable than the other. The results show that it is only the left hemisphere that is responsive to syntactic structuredness, while the two hemispheres seems to be equally responsive to semantic-pragmatic structuredness. But it is possible that the two hemispheres differ in the manner in which they make use of semantic structures: the left hemisphere in a selective manner, appropriate for the solution of a specific task, and the right hemisphere in a more diffuse and global manner.

Adolescent↗
PubMed1975

Somatosensory evoked potentials and magnitude of perception.

With step indentations of the index finger tip in randomized order, via a mechanostimulator, the tactile receptors of human skin were adequately stimulated. Recording the EEG over the contralateral and ipsilateral cortex, the evoked potentials and their 95% confidence limits were analysed. Simultaneously the psychophysical magnitude estimations were analysed. 1. The perceptual estimations were linearly related to step amplitude. 2. The early components of the E.P. show no obvious correlation to stimulus amplitude. 3. The later components (with peak latencies of 120 msec or more) show a monotone, non-linear rising function with respect to stimulus amplitude. 4. The early waves of the evoked potentials up to about 120 msec are well localized over the contralateral postcentral hand area while the late components resemble the alpha rhythm in wave length and distribution over both hemispheres. The possible role of alpha-synchronisation in the later components is discussed.

Evoked Potentials↗
PubMedDate not supplied

Rapid HIV screening at the point of care: legal and ethical issues.

In March 2000, the Canadian HIV/AIDS Legal Network released a comprehensive report entitled Rapid HIV Screening at the Point of Care: Legal and Ethical Issues. The release of the report coincided with the issuing of the first license to sell rapid HIV test kits in Canada for use by health-care professionals at the "point of care," and received considerable media attention. The report makes 23 recommendations to federal and provincial/territorial health officials, health-care professionals and their professional associations and regulatory bodies, and test kit manufacturers, with a view to ensuring that the potential benefits of this testing technology are maximized and the potential harms are prevented or minimized. We reproduce here the executive summary of the report.

AIDS Serodiagnosis↗
PubMedDate not supplied

HIV/AIDS in prisons: more new developments.

Since our last review, there have been new developments in several jurisdictions in the area of HIV/AIDS and prisons. This column reviews some important developments in Canada and in the US: the results of the evaluation of HIV/AIDS harm-reduction measures in the Canadian federal prison system; another Canadian inmate's fight for methadone maintenance treatment in prison; an important article on health care in Canadian prisons which states that there is little evidence that the federal prison system "is making any serious effort to provide treatment to any drug users"; the US Supreme Court's refusal to review a lower court's ruling permitting Alabama prisons to segregate HIV-positive inmates; an important ruling stating that inmates are entitled to receive medications in jail without interruption; and research showing that women inmates in the US are 23 times more likely to have AIDS than women in the general population.

Canada↗