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Biomedical subjects

H Brewitt

Publications and source records attributed to H Brewitt.

At least 37 records · Page 2Linked to original sources
PubMed1984

[Boeck's disease with unilateral optic nerve involvement].

A rare symptom of Boeck's disease is involvement of the fasciculus opticus. This paper reports on a patient with sarcoidosis who developed cerebral symptoms during the course of the disease; some months later he suffered an acute deterioration of vision in his right eye, with central scotoma but without papilledema. The difficulty of distinguishing this condition from bulbar neuritis in cases of multiple sclerosis is discussed.

Adult↗
PubMed1984

[Demonstration of the effects on the corneal epithelium of a mucomimetic collyrium. Study using scanning microscopy].

Ocular surface drying was studied in rabbits using an experimental model of blinking interruption. This model produces a discontinuity in the pre-corneal tear film after a few minutes of exposure to air. Changes in superficial epithelial cell structure were studied using a scan microscope. A decrease of micro-folds and an increase in epithelial cell desquamation were observed. Prolonged exposure to air produced similar cellular lesions in deeper layers. The instillation of a single mucomimetic eye-drop containing chondroitin sulphate prevented total interruption of epithelial humidification, kept the epithelial surface intact and preserved normal cellular structure.

Animals↗
PubMed1981

The basement membrane complex of the human corneal epithelium.

The present report reviews the fine structure of the basement membrane zone or complex in the normal human cornea and describes its alterations in cases of early and acute keratoconus. In normal human cornea the basement membrane zone is formed by a basal lamina (with a lamina lucida and a lamina densa), "special fibrils", collagen fibrils and assemblies of filaments. These components are less evident in the central region of the cornea than in its periphery. In early stages of keratoconus the basement membrane zone is thickened and the lamina densa displays an irregular course. In acute keratoconus, the basement membrane zone is also thickened and includes a large number of "special fibrils" as well as bundles of "microfibrils" (oxytalan fibers). The conclusion that the basement membrane complex of the corneal epithelium is equivalent to the epidermal-dermal junction of the skin is discussed.

Adult↗
PubMed1980

Morphological changes of the corneal epithelium after application of topical anaesthetic ointments.

The effect of topical anaesthetic ointments (4% cocaine, 4% xylocaine, 0.5% proparacaine, 0.2% oxybuprocaine) on the corneal epithelium of rabbits was examined using a scanning electron microscope. Even after a single application, the more toxic effect of cocaine compared to the other topical anaesthetics was evident. Cocaine caused disruption of both the plasma membrane and the cytoplasm. After a single application, the other preparations caused a marked decrease in the microvilli and microplicae, disruption of the intercellular spaces and the prominence of the cell nucleus which under normal condition is not visible. Repeated applications caused regular cell desquamation and damage to the plasma membrane and cytoplasm. The damage also affected several cell layers. The cell reactions described are clearly a consequence of the topical anaesthetics, as the ointment base itself produced no essential cell damage. The scanning electron microscope findings were supported by results from the transmission electron microscope.

Anesthetics, Local↗
PubMed1979

Sliding of epithelium in experimental corneal wounds. A scanning electron microscopic study.

The morphological changes in the rabbit cornea due to a linear wound and a central keratectomy and its reepithelization were examined under the scanning electron microscopy. After the rounding off and retraction of the edges of the wound, during the first 6 h, the stroma was infiltrated by leucocytes. First of all the superficial epithelial cells migrated over the edges of the wound to protect the exposed cleft in the tissue. After 15 h the basal epitheliel cells sent pseudopodia-like processes of varying lengths into the wound area. The migrating cells were mainly flat. During this phase the primary migration of the basal epithelial cells was followed by subsequent cell layers. In the migration, three types of cells can be distinguished: 1. very flat cells with smooth edges without microprojections, which adapt their shape to the clefts in the damaged stroma, 2. flat cells with considerably folded plasma membrane on the cell surface giving a coral-like appearance, 3. cells with voluminous cytoplasmic processes. The rapidly sliding epithelium covered the defect with star shaped growths so that after only 48 h a nearly complete closure of the wound was achieved. After 96 h the deep wound was completely covered by epithelium. The epithelial cells did not yet possess their original surface structure in that they had demonstrably fewer microvilli and microplicae than normal. Only after five days at the earliest could the normal surface relief be seen. The surface cells were predominant in the first stage of the healing process and the basal cells only in the second stage.

Animals↗
PubMed1979

Early morphological changes of the corneal epithelium after burning with hydrochloric acid. A scanning electron microscope study.

The morphological changes of the corneal epithelium after burning with hydrochloric acid were examined using a scanning electron microscope. A drop of hydrochloric acid of differing concentrations (1--0.000001 N HCl) was applied under standardized conditions to normal rabbit eyes for a reaction period of 5 or 30 min. The changes in the cell surface, which are dependent on the concentration of the acid, include a loss of microvilli and microplicae, outlining of the cell nucleus, disruption of the intercellular spaces, cell desquamation and even the most severe damage to the cell membrane and cytoplasm of the corneal epithelial cells.

Animals↗
PubMed1979

[Adie's syndrome from a neurological standpoint (author's transl)].

The findings in 22 examinations of tonic pupils, 15 of which presented Adie's syndrome, are described. The neurological and chemical as well as liquor analyses are normal except for the well known tendon reflex anomalies. Neurophysiologically, in 7 of 10 examinations mild disruptions in the sensory nerve conduction velocity were observed. The literature of the last 10 years, where it is of interest from a neurological standpoint and where it relates to the site of damage or to the origin of the tendon reflex abnormalities in Adie's syndrome, is discussed. Adie's syndrome is interpreted as damage to the peripheral nervous system in a polyneuropathic form.

Adie Syndrome↗
PubMed1979

[Concerning the Toti operative procedure (author's transl)].

It has been shown by a series of 127 dacryocystorhinostomies using the Toti technique, that this operation, which is independent of age or aethiology, can be performed using a simple procedure and a short hospitalization time. The success rate of over 90% indicates that this operation should be used as a standard procedure in preference to the intubation with polyethylene tubes.

Calculi↗
PubMed1979

[Light microscope and scanning electron microscope findings in acute keratoconus (author's transl)].

An acute keratoconus was examined for the first time using a scanning electron microscope. The alterations in the epithelium of the cornea consisted of a reduction in microvilli and microplicae structures, disruption of the intercellular spaces with raised protrusions of epithelial cells in the region of the peak of the keratoconus or even of the complete disappearance of all regular surface structures. In the stroma distinct irregularities in the lamellae, sometimes even the formation of cavities in the region of the cornea peak, could be seen. These findings correlate well with the light microscope pictures and with the published transmission electron microscopic results.

Acute Disease↗
PubMed1978

[Perimetry during monocular and binocular fixation with the phase-difference haploscope of Aulhorn].

For the first time it was possible to compare perimetry during monocular and binocualr fixation under homogeneous conditions by the aid of phase-difference haploscopy. A binocular perimetry was not practicable using common perimeters. The examination was based on the anatomical fixed papilla nervi optici, which appears in the visual field as the blind spot. Its extension corresponds more to the anatomical size during binocular examination than during monocular examination. The difference is highly significant. Likewise the binocular perimetry refers to the quality of reproduction of paracentral retinal diseases significantly improved compared with the monocular examination. Supposing that the use of a larger fixation target during monocular perimetry contributes to the stabilization of normal eye movements, all examinations were additionally made with two fixation targets of different sizes. We have shown that there is no significant difference between the measurement either concerning the extension of the blind spot or the paracentral retinal diseases, which means a larger fixation target represents no fixation aid.

Fixation, Ocular↗