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Biomedical subjects

E R Büchi

Publications and source records attributed to E R Büchi.

34 records · Page 2Linked to original sources
PubMed1993

Topical immunoglobulins for epithelial herpes simplex keratitis.

A new immunoglobulin preparation for topical administration in the eye has been developed. The tolerance to this preparation was tested in a phase I/II study, in combination with the antiviral drug trifluorothymidine, in 5 patients with untreated episodes of herpes simplex epithelial keratitis. The clinical course of these patients was within usual limits, with a mean healing time of 6.6 days (range 2-15 days). No undesirable effects were observed. Our findings suggest that this new treatment modality is safe and offers a new perspective, but additional studies are required to determine its efficacy.

Adult↗
PubMed1992

Cell death in the rat retina after a pressure-induced ischaemia-reperfusion insult: an electron microscopic study. I. Ganglion cell layer and inner nuclear layer.

In rats, a pressure-induced ischaemia-reperfusion insult can lead to retinal cell death. In order to elucidate the underlying mechanisms, we performed a qualitative study of the ultrastructural morphology of degenerating retinal cells in the ganglion cell and inner nuclear layers at several time points after the insult. Three morphologically distinct types of cell death could be individualized. Type I was characterized by progressive karyo- and cytolysis and was consistent with necrosis. Type II exhibited progressive shrinkage and condensation of the nuclear and cytoplasmic components followed by heterophagic elimination, thus resembling apoptosis. Type III was characterized mainly by homogenization of the nucleoplasm and cytoplasm and dilation of the perinuclear cisternae and endoplasmic reticulum, thus showing features of 'non-lysosomal vesiculate' cell death. This study lends support to the concept that there may exist a fair but limited number of types of cell death in the retina.

Animals↗
PubMed1992

Oral acyclovir for herpes zoster ophthalmicus.

BACKGROUND: Reports on the natural history of herpes zoster ophthalmicus stress its high morbidity related to vicious scars on eyelids, ocular complications, and post-herpetic neuralgia. Early treatment with oral acyclovir is effective, but the optimal duration of treatment has not been defined. METHODS: The authors performed a bicentric, prospective, randomized, double-masked study of 86 patients with acute herpes zoster ophthalmicus, within 72 hours of skin eruption, who received oral acyclovir (800 mg 5 times daily), either for 7 days (plus 7 days oral placebo) or for 14 days. All patients concomitantly received ophthalmic 3% acyclovir ointment; follow-up was at least 6 months. RESULTS: Statistical analyses of subjective symptoms, skin lesions, and ocular complications showed no significant differences between the groups, suggesting that a 7-day course of treatment was sufficient. Drug tolerance was good. Pooled data from both groups corroborated earlier reports that prompt treatment with oral acyclovir reduces the severity of the skin eruption, the incidence and severity of late ocular manifestations, and the intensity of postherpetic neuralgia. At 6 months, late ocular inflammatory complications were seen in 29.1% of our 86 patients, versus 50% to 71% of untreated patients described by others. Only 13% of our patients experienced post-herpetic neuralgia, which in no case required the use of analgesics. CONCLUSION: The authors believe it is not useful to prolong treatment with 800 mg of oral acyclovir 5 times daily for more than 7 days in herpes zoster ophthalmicus. This study confirms the efficacy of oral acyclovir not only against skin lesions and ocular complications, but also against postherpetic neuralgia in herpes zoster ophthalmicus.

Acyclovir↗
PubMed1992

[Degeneration of retinal cells of the rat in pressure-induced ischemia-reperfusion damage: an electron microscopy study].

An ischaemia-reperfusion insult to the retina was produced in one eye of 29 rats by transitory elevation of the intraocular pressure. The ultrastructural morphology of the degenerating retinal cells was studied at several time points after the insult. Three morphologically distinct types of cell death could be individualized. Type I exhibited progressive karyolysis and cytolysis and was consistent with necrosis. Type II was characterized by progressive shrinkage and condensation of the nucleus and cytoplasm followed by heterophagic elimination, thus resembling apoptosis. The main features of type III cell death were homogenization of the nucleoplasm and cytoplasm and dilatation of the perinuclear cisternae; thus, they were evocative of "non-lysosomal vesiculate" cell death. Transitional stages were observed as well.

Animals↗
PubMed1992

[Orbitocranial plasmacytoma: a case report].

A female patient aged 79 years suffered from a unilateral, slowly progressive and painless exophthalmus. The investigations lead to the diagnosis of a voluminous plasma cell tumor involving the fossa infratemporalis, a part of the lateral orbit, as well as the middle and anterior cerebral fossae. This rare case is described and placed in its clinico-pathological context.

Aged↗
PubMed1992

Distended optic nerve sheaths in Leber's hereditary optic neuropathy.

Distension of the optic nerve sheaths is a feature of Leber's hereditary optic neuropathy (LHON) that has attracted attention only recently. We followed a patient with LHON for 23 years and obtained his eyes for pathological examination after death. We report the first histologic description of distension of the optic nerve sheaths, together with typical histopathological findings of LHON. Distension of the optic nerve sheaths could not be accounted for by any etiology other than LHON, although the precise pathogenic mechanisms remain enigmatic.

Adult↗
PubMed1992

Cell death in rat retina after pressure-induced ischaemia-reperfusion insult: electron microscopic study. II. Outer nuclear layer.

Pressure-induced ischaemia-reperfusion insult of sufficient duration leads to significant retinal damage in rats. In this report we describe the morphology of degenerating cells in the outer nuclear layer at several time points after the insult, as observed by electron microscopy. Only one death pattern was observed. It was characterized by asynchronous involvement of individual cells, progressive densification and shrinkage of nuclear and cytoplasmic components, and a final phase of disaggregation and heterophagic elimination by Müller cells. This pattern of cell death combined features of an apoptosis-like mechanism and secondary necrosis.

Animals↗
PubMed1991

Pressure-induced retinal ischemia in rats: an experimental model for quantitative study.

The advent of treatment modalities with the potential to ameliorate retinal ischemic injury calls for methods allowing their quantitative assessment. We thus established a model of pressure-induced retinal ischemia/reperfusion injury in rats. The intraocular pressure (IOP) was raised to 110 mm Hg by cannulation of the anterior chamber for a duration of 0, 90 or 120 min. The eyes were reperfused for 3 or 7 days. Morphologically, retinal injury occurred in a pattern consistent with retinal and choroidal vascular occlusion. Damage increased in severity with prolonged durations of ischemia. Morphometric determination of the mean thickness of inner retinal layers (MTIRL) revealed significant differences between controls and the 90- or 120-min ischemia groups (p less than 0.05 and p less than 0.01, respectively). The difference in MTIRL between 3 and 7 days of reperfusion was not significant. Replacement of normal saline by a solution of 5% dextrose in the hydrostatic device used to increase the IOP led to a decrease in retinal injury after 120 min of ischemia (p less than 0.01). This model combines a relatively simple methodology, cost-effective execution and a fast, semicomputerized method of quantitation. Depletion of carbohydrates during ischemia may contribute to retinal injury in this model.

Animals↗
PubMed1990

Respiratory epithelium in a cystic choristoma of the limbus.

A female newborn had a cystic, whitish gray mass at the inferotemporal limbus of the left eye. At age 3 weeks, the newborn underwent excision of the tumor, corneal patch grafting, and superior sector optical iridectomy. Histopathologic and electron microscopic examination of the excised tissue revealed a choristoma consisting of cysts lined with respiratory epithelium. To our knowledge, respiratory epithelium in a limbal choristoma has not been previously reported.

Choristoma↗
PubMedDate not supplied

Immunopathological findings in posterior scleritis.

Posterior scleritis can present with a variety of symptoms, and its clinical diagnosis is therefore difficult. Little is known about the pathogenesis and the cellular effector mechanisms. This case report presents the immunopathological findings of posterior scleritis in the enucleated eye of a 28-year-old female with no known underlying disease. The cells infiltrating the scleral fibers consisted predominantly of T cells. Many of them were CD4 cells. Clusters of T and B cells were found in perivascular areas. No signs of primary vasculitis were seen. The cellular infiltrate in posterior scleritis shows features compatible with a T-cell-mediated (autoimmune) disorder.

Adult↗
PubMedDate not supplied

Eccrine acrospiroma of the eyelid with oncocytic, apocrine and sebaceous differentiation. Further evidence for pluripotentiality of the adnexal epithelia.

A wide variety of sweat gland tumors occur in the eyelids. We used light and electron microscopy to investigate an eccrine acrospiroma showing areas of oncocytic, apocrine and sebaceous differentiation. To our knowledge this is the first report of an oncocytic lesion arising from an eccrine sweat gland, and only the second report of such a lesion arising from the skin. Furthermore, apocrine and sebaceous differentiation are atypical in lesions originating from sweat glands. The wide spectrum of differentiation in this adenoma lends further support to the concept of pluripotentiality of the adnexal glandular epithelia.

Adenoma, Sweat Gland↗
PubMedDate not supplied

Age-dependent phenotypic expression of a pattern dystrophy of the retina.

We studied a family with pattern dystrophy of the retina (PDR) in order to elucidate the clinical course of the disorder, relations between the different forms, and the mode of inheritance. Thirty-nine family members, representing three generations, underwent a thorough ophthalmological examination, with fluorescein angiography whenever a macular abnormality was suspected. Of family members over the age of 32 years, 46.7% showed signs of PDR. We classified the clinical forms of PDR in this family into four types: minimal lesion, pseudovitelliform type, butterfly-spider type, and late-stage lesion. These forms were predominant in the order cited in age groups 31-40 years, 41-50, 51-60, and > 60 years. Significant visual loss occurred only after the age of 50 years, when 8 of 14 eyes had visual acuity of less than 20/25. Inheritance was autosomal dominant. PDR presented different clinical forms in members of this family, and in successive age classes patterns of increasing severity prevailed. Thus, the different phenotypic forms apparently represent transient stages related to the age of the patient.

Adult↗