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Biomedical subjects

R Rix

Publications and source records attributed to R Rix.

At least 37 records · Page 2Linked to original sources
PubMed1979

[Changes in the outer plexiform layer of the rabbit retina after long-term application of vincristine].

Rabbits which had been intravenously injected with Vincristine for six weeks showed changes in the outer plexiform layer of the retina after one year, which suggests the destruction of receptor cells, bipolar ganglion cells, and horizontal cells. Compensated cell damage accompanied by loss of microtubuli in the cytoplasma, autolytic vacuoles, granular material deposits, and membrane changes of the ribbon complex were frequently observed. A comparison between axons and dendrites showed a predominance of damaged dendritis over axons. Because short-term studies have not produced the same results, different regeneration capacities, which might have their origin in the endoplasmatic reticulum, are discussed.

Animals↗
PubMed1979

[The influence of vigilance on DC response in human visual evoked potential (author's transl)].

Visual evoked cortical potentials elicited by long-lasting stimuli of red light were examined in eight subjects under different conditions of vigilance. The DC components of the evoked potentials were compared with the delta and theta activity (0-7.5 Hz) of the EEG by means of frequency power spectra. The results are: 1) A proportional relationship exists between the amplitude of the negative DC component of the evoked potential and the theta and delta activity in the EEG. 2) Under conditions of low vigilance the negative DC potential does not return immediately to the baseline after the off-effect. Instead it may reach a second peak. 3) Under conditions of high vigilance, the DC potential may reverse its polarity. Its return to the baseline following the off-effect is immediate. 4) No dependence of the cortical DC potential on the intensity of the light stimulus could be demonstrated. 5) Since the negative potential outlasts the visual stimulus and could be recorded at the occiput and the vertex, it may be regarded as a nonspecific arousal reaction. Furthermore, since the positive DC potential can only be recorded at the occiput, it is regarded as a specific stimulus-correlated response.

Adult↗
PubMed1978

[Hydroxychinoline- and zinc-treated acrodermatitis enteropathica and electroretinographic findings (author's transl)].

A meanwhile 13 years old boy had to be treated by hydroxychinolines for a severe acrodermatitis enteropathica since his 1st year of life. At the age of 5 years he showed visual deterioration by atrophia optici. Dose reduction and application of different halogen substitutions were tried. Finally, it was daily oral zinc application and continuous control of the serum zinc level which made disappear all cutaneous and mucous symptoms. At an unchanged ophthalmoscopic status, there occurred a slight raise of vision, an enlargement of peripheric campus and a normalization of the electroretinographic potentials.

Acrodermatitis↗
PubMed1978

[Retinographic alterations in different forms of congenital cataracta (author's transl)].

In a follow-up study of patients suffering from congenital cataract, particular attention was paid to the electroretinogram. Besides hereditary lens opacifications and rubella embryopathy, galactosaemia and spontaneous idiopathic hypoglycemia occurring in children and infants were examined. The question, how much biochemical factors can influence the ERG, is becoming more important.

Cataract↗
PubMed1977

[The D.C. response in the human electroretinogram under different degrees of wakefulness (author's transl)].

A report is given on the D.C. component of the human ERG following stimulation with red light of varying intensities and under different conditions of vigilance. The degree of the subject's wakefulness can be followed by looking at certain frequency components of the power spectrum of the occipital EEG. 1. The ERG remains uninfluenced by the degree of the subject's vigilance. 2. Red light is especially suited for eliciting separately photopic an scotopic responses in the on-effect of the ERG, possibly in the off-effect also. The D.C. potential is regarded as a component of the scotopic b-wave. The photopic x-wave can be recorded with very low stimulus intensities and stays clearly separated from the D.C. component.

Electroretinography↗
PubMed1976

[A histological and electron microscopic study of the rabbit retina after application of vincristin (author's transl)].

Temporary electrophysiological damage to the rabbit eye proportional to dosis and application time was observed after application of Vincristin (Lilly). Cell destruction in all retinal layers was observed upon histological and electron microscopic examination of the animals. The outer segments of the receptor cells showed chiefly diffuse damage, and the pigment epithelial cells showed a high incidence of reorganization. Follow-up examination one year later showed this damage to be partially reparable, especially when very high doses had not been applied. Regeneration of the outer segments was observed. Destruction through pyknosis of the nucleus and cytoplasmal destruction was observed in a small number of receptor cells, bipolar ganglion cells, and ganglion cells. This also explained the absence of lasting functional abnormalities in the ERG and EVP.

Animals↗
PubMed1976

[Alport-syndrom with participation of the cornea and alterations of ERG (author's transl)].

A description of a 26-year-old patient who had hearing difficulties, progressive nephropathy, and conus of the lens in both eyes is given. The ERG was below normal and the EOG remained normal. About the same time the nephropathy affliction occurred, a ringed abscess appeared in the left eye. Afterwards it healed with a scar, but half a year later the same affliction appeared in the right eye.

Adult↗