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Biomedical subjects

E Messmer

Publications and source records attributed to E Messmer.

32 records · Page 2Linked to original sources
PubMed1987

Orbital computed tomography. Does it help in diagnosing the infiltration of choroid, sclera and/or optic nerve in retinoblastoma?

High-resolution computerized tomography of the orbit was performed in patients with histologically proven retinoblastoma to assess the efficacy of CT in delineating the retro-orbital extent of the tumor and determining if the optical nerve was involved. High-resolution CT proved able to accurately delineate tumor size, tumor localization, tumor calcification, retro-orbital and intracranial tumor growth. Microscopical tumor spread past the lamina cribrosa of the optic nerve, however, could not be detected by CT.

Child↗
PubMed1984

Cavernous hemangioma of the retina. Immunohistochemical and ultrastructural observations.

A 6-month old girl had unilateral leukokoria. Because retinoblastoma could not be excluded, the blind left eye was enucleated. Histopathologically, a total retinal detachment associated with a widespread cavernous hemangioma of the retina and a preretinal membrane were found. The specimen was further examined by immunohistochemistry and electron microscopy to determine the origin of the preretinal membrane and to study the anatomy of the telangiectatic retinal vessels. The preretinal membrane was mostly composed of spindle-shaped cells that demonstrated immunohistochemically the presence of glial fibrillary-acidic protein and showed, ultrastructurally, numerous glial filaments in their cytoplasm. These findings support the view that this membrane was of glial origin. By electron microscopy, the telangiectatic retinal vessels displayed the anatomic features normally encountered in retinal vessels, which accounts for the absence of exudates observed clinically and angiographically in cases of cavernous hemangioma of the retina.

Astrocytes↗
PubMed1983

Nine cases of cavernous hemangioma of the retina.

The findings in nine patients with cavernous hemangioma of the retina confirmed the accepted characteristics of this malformation. Clusters of dark-red saccular aneurysms within the inner retinal layers were partly covered by a white epiretinal membrane. There was no clinical or angiographic evidence of exudation from the angioma and there was no growth during a median follow-up period of 6.3 years. The size of the aneurysms, the extent of the lesion, and the associated venous malformations varied greatly from case to case. Fluorescein angiographic findings during follow-up periods of as much as 16 years suggested progressive thrombosis and organization of the angioma.

Adolescent↗
PubMed1983

Pigmented conjunctival cysts following tetracycline/minocycline therapy. Histochemical and electron microscopic observations.

Unpigmented and pigmented cystic epithelial inclusions were found bilaterally within the lower palpebral conjunctiva temporally of a 31-year-old man. He had a history of tetracycline/minocycline therapy for 14 years because of acne vulgaris. The cysts were studied by light and electron microscopy, histochemistry, and ultraviolet light. By light microscopy the unpigmented cysts contained faintly eosinophilic globular material that disclosed yellowish-green autofluorescence indicating the presence of tetracycline/minocycline. The pigmented cysts revealed laminated eosinophilic to brownish concretions that also showed yellowish-green autofluorescence. Autofluorescence, however, decreased with increasing brown pigmentation of the concretions. Histochemically, the pigment, which failed to show the staining characteristics of lipofuscin, melanin or iron, probably represented an oxidation product of tetracycline. By electron microscopy the cysts contained moderately electron dense amorphous material as well as degenerating epithelial cells. The epithelial cells lining the conjunctival cysts, did not contain membrane-bound, large, pigment granules within their cytoplasm as has been demonstrated in the colloid and follicular epithelium of the thyroid following minocycline therapy.

Acne Vulgaris↗
PubMed1983

Light and electron microscopic study of Dalén-Fuchs nodules in sympathetic ophthalmia.

A light and electron microscopic study was undertaken in an effort to establish the origin of the "epithelioid" cells in Dalén-Fuchs nodules from an eye enucleated because of sympathetic ophthalmia. The nodules were visible as minute (130-160 microns), round, grayish-white mounds elevating the retinal pigment epithelium. Bruch's membrane appeared intact in all the sections examined. By electron microscopy the "epithelioid" cells had round to oval nuclei with abundant, relatively lucent cytoplasm containing parallel profiles of rough-surfaced endoplasmic reticulum, prominent Golgi lamellae, clusters of polyribosomes, and scattered mitochondria. Many interdigitations of the plasma membranes, some of which exhibited fascia adherens type attachments, were observed. Some cells within the nodules showed large membrane-bound phagosomes containing laminated structures. Other "epithelioid" cells displayed moderately electron dense membrane-bound granules that appeared to be early precursors of lipofuscin granules. Examination of the nodules under ultraviolet light showed myriad autofluorescent yellowish-orange dots consistent with lipofuscin. Additionally, a montage of electron micrographs from the edge of the nodule, coupled with the above findings, provided support to the concept proposed by Ishikawa and Ikui (1972) that the "epithelioid" cells in Dalén-Fuchs nodules represent transformed retinal pigment epithelial cells forming a cage-like framework within the nodule. This study also emphasizes the remarkable capabilities for differentiation by the retinal pigment epithelial cells.

Female↗
PubMedDate not supplied

[The question of midface growth inhibition following retinoblastoma treatment in early childhood].

99 patients treated for bilateral retinoblastomas in the University Hospital of Essen between 1965 and 1983 were followed up for midface growth inhibition for an average period of 15 1/2 years. Depending on the type of treatment employed the patients were divided into four groups: Local tumor treatment using cryotherapy or laser techniques, ophthalmectomy alone, radiotherapy alone, and combined ophthalmectomy and radiotherapy. Statistically significant differences between the treatment groups were found regarding such symptoms as hypoplasia of the zygomatic bone, hypoplasia of the transversal orbit, hypoplasia of the temporal fossa, hypoplasia of the root of the nose as well as hypotelorism and enophthalmos. Combined surgery and radiotherapy caused the most severe growth disorders, followed by radiotherapy alone and ophthalmectomy alone. With local treatment detectable growth disorders were observed, if at all, only as a result of contralateral radiation scatter. Orthovoltage radiotherapy was found to produce growth disorders of significantly higher severity than megavoltage radiotherapy.

Adolescent↗