PubMed Health⌕ Search

Biomedical subjects

A Mathis

Publications and source records attributed to A Mathis.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Effect of a rotating sound source on postrotatory nystagmus].

In 10 healthy individuals the influence of a rotating sound source (loudspeaker, narrow band noise 500 Hz, 70 dB SPL, 120 degrees/sec.) on the postrotatory nystagmus was investigated. If the loudspeaker was rotating in the opposite direction of the fast postrotatory nystagmus component, the duration and intensity of the postrotatory nystagmus was amplified by about 30%. If the loudspeaker was rotating in the direction of the fast postrotatory nystagmus component, no changes were seen.

Adult↗
PubMed1987

Experimental study of the intra-ocular penetration of ketoconazole in rabbits.

We studied 11 healthy rabbits and 15 rabbits with experimentally induced Candida endophthalmitis. Using a microbiological procedure, ketoconazole levels were determined 1, 2, 4, 8 and 24 h after its oral administration. Ketoconazole penetration was average in the aqueous humour, significant in tears and poor in the vitreous. Vitreous penetration was not detectable in healthy rabbits or in rabbits with chorioretinits exhibiting little or no vitreous reaction. Such penetration was only significant in rabbits exhibiting massive vitreous exudation; however, in such rabbits, penetration was not always observed (only in 2 out of 6 animals). Given these results, the treatment of Candida endophthalmitis in humans using ketoconazole would appear to be of questionable value.

Animals↗
PubMed1987

[Does optokinetic stimulation modify directional hearing?].

The directional hearing of 20 healthy test persons, all with normal hearing abilities, was tested using a special self constructed equipment. Under the repeated influence of an optokinetic stimulation (rotating light beams on a semicircular screen in a completely darkened room) no statistically significant deviation of the directional hearing reactions could be detected.

Adolescent↗
PubMed1986

[Alleviation of ocular complications of the hyperviscosity syndrome in Waldenström's macroglobulinemia using plasma exchange].

Two patients presenting ocular complications of hyperviscosity syndrome in Waldenström's macroglobulinemia have been treated by plasmapheresis after inefficiency of immunosuppressive therapy. Plasma exchange seems an useful treatment as shown by clinic and angiographic improvement. In each case improvement of retinopathy was correlated with decrease of serum IgM level and blood viscosity measured by isotopic method. Fluorescein angiography, easily repeated, seems a very good method for following hyperviscosity syndrome in Waldenström's macroglobulinemia.

Aged↗
PubMed1985

Some ultrastructural aspects of the vitreoretinal juncture.

The ultrastructural study of the vitreoretinal juncture was carried out by comparing two groups of patients: 6 young subjects under 25 years and 6 older subjects over 70. Retinal samples were taken from the posterior pole, the equator and the extreme periphery. Our work shows that the morphological modifications of the vitreoretinal juncture during the aging process vary following location. The most original alteration, never observed before, appears in the equatorial region: it consists of a widening of the intercell space filled with fibrils adhering to Müller's cells. It builds up an adhesion zone between the vitreous and the retina which is not visible during clinical investigations; it can create a tear during the posterior vitreous detachment.

Adolescent↗
PubMed1985

[Lattice degeneration of the peripheral retina: ultrastructural study].

The ultrastructural study of a case of snail track degeneration shows the presence of lipid inclusions in both the glial and the macrophage cells in every layer of the retina, and the existence of intraretinal fibers different from collagen fibers appearing to be glial filaments similar to those found in astrocytic gliomes and to the Rosenthal fibers observed in senile nervous cells. Other features were thinning of the retina and absence of blood vessels in the retina. There are no abnormalities of the vitreo-retinal juncture. All the lesions are in agreement with those observed by Daicker [Ophthalmologica, Basel 165: 360-365, 1972; Klin. Mbl. Augenheilk. 172: 581-583, 1978] with some differences, however. They are different from those found in lattice degeneration. They show that snail track degeneration is a specific form of peripheral retinal degeneration which is quite different from lattice degeneration and must not be considered similar.

Choroid Neoplasms↗
PubMed1985

[Changes in perimetric defects in chronic open-angle glaucoma studied by automated perimetry (Octopus)].

The Octopus automatic perimeter was used to determine changes in visual field of 90 patients with chronic open angle glaucoma. Mean sensitivity value calculated from 62 of the 73 points of the apparatus program 33 - after elimination of those 11 points corresponding to Mariottes's zone and the central 10 degrees - provides an effective paracentral visual field monitoring numerical parameter. The authors named the parameter "global value". Statistical analysis of "global value" variations between two successive examinations showed: significant improvement between the first and the second tests; disappearance of the phenomenon between two further successive tests. The reasons for this pseudo-improvement remain unclear: perhaps the patients experience gained from the precious tests plays a part in the phenomenon. This should in any case be taken into account when assessing possible aggravation between two tests. Analysis of results suggests that, as a standard evaluation method, any "global value" degradation of the order of 1 db between the first two tests and 3 db between two successive tests performed after the second one is significant of a visual field degradation with a 1% range of error.

Analysis of Variance↗
PubMed1985

[Significance of electrocochleography within the scope of audiologic diagnosis].

Despite the extensive applicability of brainstem evoked response audiometry (= BERA), electrocochleography (= ECochG) occupies an undisputed place among audiological diagnostic methods. It is useful, among other things, in the early identification or confirmation of hearing defects in children, since it permits measurement of the auditory threshold and of the characteristics of the suprathreshold area, and may aid in excluding ambiguous findings resulting from subjective audiometric or other objective audiometric methods in certain cases. In this regard, it makes possible a valid early prescription of hearing aids to children with auditory defects; in addition, in certain cases it provides valuable additional information and can be employed in solving simulation and masking problems. The diagnostic validity of ECochG in Menière's disease requires continued investigation. To sum up, we can say that ECochG should be performed only at centres where the frequency of examinations guarantees the necessary expert knowledge.

Audiometry↗