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Biomedical subjects

L Voldrich

Publications and source records attributed to L Voldrich.

At least 19 recordsLinked to original sources
PubMed1988

Light and electron microscopic appearance of the inner ear in juvenile ceroid lipofuscinosis (CL).

Inner ear cells were studied by histology, histochemistry and electron microscopy in one case of juvenile form of ceroid lipofuscinosis (Batten's disease). It was found that despite the clinically normal range of auditory acuity (nonaudiometric evaluation) there was a storage process of moderate degree with intralysosomal deposition of a lipopigment of variable ultrastructure with two patterns predominating, curvilinear and fingerprint. Storage was demonstrable in slightly variable degree in every cell type including the receptor cells of the organ of Corti and sensory cells of crista ampullaris. The cochlear neurons displayed a so far unique storage with enormous monovacuolar distension of perikarya comparable only to the lymphocytic vacuolization also present in the juvenile form of the disease. The distension of vacuoles was only partly caused by accumulation of the lipopigment mass and actually led to neuronal deterioration. The results shown here offer a new modell for functional-structural relationship and point to the urgent need of further studies of the inner ear in CL and lysosomal storage generally.

Child↗
PubMed1987

Correlative study of sensory cell density and cochlear length in humans.

In the group of 50 cochlea from 28 men aged 38-73 years a great variability in the length of the cochlear duct was found ranging from 28.0 to 40.1 mm. The variability in the number of inner and outer hair cells is not so prominent and the same holds for the variability in density. Average densities of the inner and outer hair cells decrease with increasing cochlear length. However, the long cochleae have a greater number of hair cells which indicates that long cochleae have more sensory cells in a given frequency region.

Adult↗
PubMed1987

Modified staining technique for surface preparation of the organ of Corti.

A simple technique for the staining of the inner ear tissues using toluidine blue and Ehrlich haematoxylin is described. The method is very convenient for histological evaluation of hair cell counts, for estimation of the number of scars in the reticular lamina, for observing the arrangement of stereociliary pattern and for the detection of traumatic changes after noise exposure. The method described proves to be very useful for histological examination of human temporal bones as well and makes possible an immediate evaluation of the hair cells of the human cochlea and direct correlation of the inner ear pathology with audiometric data.

Animals↗
PubMed1984

Involution of the auditory neuro-epithelium in a tiger (Panthera tigris) and a jaguar (Panthera onca).

Numerical atrophy of the hair cells of the organ of Corti of the inner ear in a 14-year-old tiger and a 17-year-old jaguar is described. The decrease in number of sensory hair cells is considered to represent physiological atrophy caused by the process of ageing. The findings are compared with previous observations on man, guinea-pigs, shrews, and bats. The development of the physiological involution of the hearing neuro-epithelium is discussed.

Aging↗
PubMed1982

The role of the spiral ligament in cochlear mechanics.

Maximum deflection of the basilar membrane (BM) in fresh guinea pig cochlea preparations attains values attaining roughly half the width of the membrane. Displacement of the BM is made possible by the elastic spiral ligament, which participates directly in dynamic processes of cochlear mechanics. That the movement is transmitted to the spiral ligament during experimental deformation of the BM by an instrument is borne out also by structural changes in the lateral wall epithelium in acoustic trauma and by vascular changes produced by chronic acoustic stress.

Animals↗
PubMed1980

Comparative method for the study of structural damage in acoustic trauma.

The traumatic dose 50 (TD50), similar to the lethal dose (LD50) widely used in pharmacology, was determined in guinea pigs for varying intensities and varying durations of exposure to a band of noise. The method proposed permits the comparison of results in studies of acoustic trauma caused by noises of various characteristics in different species of experimental animals.

Animals↗
PubMed1980

[Diseases of the inner ear due to excessive noise].

Noise causes damage to the auditory system either to excessive kinetic energy, which results in acoustic trauma once the mechanical resistance capacity of internal ear tissues has been exceeded; or else, a long term exposure to noise of non-traumatic intensity can exhaust the sensory cell metabolism to such an extend that numeric atrophy of the auditory neuroepithelium will develop as a result of hyperactivity. Progressive necrosis will develop if Corti's organ barrier against endolymph is broken. The pathomorphological types of auditory organ damage are in agreement with the characteristic functional manifestations found in audiological investigation.

Animals↗
PubMed1979

Noise-noise effect upon the spreading of the posttraumatic progressive necrosis in the organ of Corti.

Progressive necrosis of the organ of Corti caused by a disturbance of the ionic composition of the Cortilymph resulting from the infiltration of endolymph into the organi of Corti after traumatization of its barrier against the scala media, is greatly intensified by posttraumatic stimulation with noise of physiological intensities. This effect is attributed to oscillation of the cochlear partition, with resultant greater blending of the Cortilymph and the endolymph. Stimulation augments necrosis fourfold towards the base of the cochlea and twofold towards the helicotrema. Posttraumatic stimulation is one of the factors which markedly potentiate the regressive effect of acoustic trauma.

Acoustic Stimulation↗
PubMed1978

Idiopathic hair cell loss in the guinea pig.

An incidence of specific, marked sensory cell loss affecting 12--88% of the outer hair cells in the third cochlear turn was found in a group of 130 healthy, coloured, intact guinea pigs divided into three age groups (6 weeks, 7 months, and 3 years). The pathological findings were compared with a known physiological norm. At 7 months, the disorder occurred in 8% of the animals, whereas at 3 years 30% were involved. The etiology of the above finding is at present still obscure.

Animals↗