Light and electron microscopic study of a case of multiple granular-cell tumor of the ascending colon is presented, and the relevant medical literature is reviewed. It seems that the biologic behavior of this tumor in the colon does not differ from that in other locations. Histologically, a few granular cells are seen in neural tissue in the vicinity of the tumor, suggesting a close relation of the tumor to the neural tissue. Electron-microscopically, the granular cells resemble Schwann cells more closely than neural cells and axons. Histochemically, the granules of the tumor cells show autofluorescence and high activity of acid phosphatase, which was located electron-microscopically in the limiting membranes and matrices of the granules. It is suggested that the granular-cell tumor is a neoplasm of Schwann-cell origin with a unique metabolism that causes acceleration of autophagocytosis and accumulation of ceroidlipofuscin.

Colonic Neoplasms↗

PubMedDate not supplied

Local ocular immunotherapy for experimental allergic conjunctivitis.

PURPOSE: We studied the efficacy of eyedrops as local ocular immunotherapy against experimental allergic conjunctivitis. METHODS: Guinea pigs were sensitized with an intraperitoneal injection of ovalbumin (OA). Three weeks after the sensitization, a low concentration (10 microg/mL) of OA eyedrops was administered once a day for 3 weeks. Six weeks after the sensitization, an allergic inflammation was provoked with 20 mg/mL of OA eyedrops. RESULTS: In conjunctival clinical scores 30 minutes after the allergen challenge, there was no significant difference between the controls and the treated group. The total number of inflammatory cells in the conjunctiva 8 hours after the allergen challenge was significantly decreased in the treated group (60.8 +/- 23.2 cells/field) compared with the control group (199.1 +/- 83.4 cells/field). Eosinophils in the conjunctiva 24 hours after the allergen challenge were also significantly decreased in the treated group (22.1 +/- 15.5 cells/field) compared with the control group (50.3 +/- 15.0 cells/field). CONCLUSIONS: In this study, local ocular immunotherapy mainly suppressed the late phase reaction of allergic inflammation. These results coincide with previous studies of immunotherapy in which a subcutaneous injection was used. Local ocular immunotherapy is effective against experimental allergic conjunctivitis.

Allergens↗

PubMedDate not supplied

Short wavelength light-induced retinal damage in rats.

PURPOSE: To evaluate short wavelength light-induced retinal damage in rats. METHODS: Pigmented rats were exposed to 300-500 nm wavelength light for 30 seconds, 1, 3, 10, 20, 60, or 90 minutes. Electroretinogram a-, b-, and c-waves were recorded 48 hours after the exposure. RESULTS: While the a- and b-wave amplitudes were reduced significantly after exposures of 60 minutes and longer, the c-wave amplitude was reduced after only 3 minutes of exposure. CONCLUSIONS: Rat retinal pigment epithelium is more sensitive to damage by exposure to 300-500 nm wavelength light than the neural retina.

Animals↗

PubMedDate not supplied

Uveitis-glaucoma-hyphema syndrome after posterior chamber intraocular lens implantation.

This article describes uveitis-glaucoma-hyphema (UGH) syndrome following posterior chamber intraocular lens (PCIOL) implantation in a 51-year-old male patient who had had intermittent blurred vision for 2 years prior to cataract surgery. We found the lens haptics fixed in the sulcus and the lens rotated. The lens was extracted and a new implant inserted with a transscleral suture. Etiology of the syndrome in this patient was an unstable sulcus fixation.

Glaucoma↗

PubMedDate not supplied

Retinal light damage: protective effect of alpha-tocopherol.

We studied histologically the protective effect of alpha-tocopherol to retinal light damage. After 3-week-old albino rats were fed with an alpha-tocopherol deficient or supplemented diet and kept in a 12-hour dim light/12-hour dark environment for 8 weeks, each animal was exposed to intense light (2500 lux) for 1, 3, 6, 12, 24, and 72 hours. The eyes were enucleated and prepared for transmission electron microscopy study and image analysis of phagosomes. Before light exposure, the alpha-tocopherol content of the neural retina of the deficient and supplemented groups was 0.3 microgram and 23.34 micrograms, respectively. After 1- and 3-hour exposures, morphological changes in the retinal pigment epithelium and photoreceptor membranes were more extensive in the deficient group than in the supplemented group. After a 24-hour exposure, pyknotic photoreceptor nuclei were more numerous in the deficient group than the supplemented group. After 3-, 6-, and 12-hour exposures, large phagosomes were more numerous in the deficient group than in the supplemented group. These findings suggest that alpha-tocopherol can protect the retina from light injury for up to 24 hours of exposure.

Animals↗

PubMedDate not supplied

A case of frosted branch angiitis with yellowish-white placoid lesions: fluorescein and indocyanine green angiography findings.

Severe, white sheathing of the retinal vessels and yellowish-white placoid lesions, suggesting frosted-branch angiitis, were found in both fundi of a 24-year-old woman. Fluorescein angiography showed hypofluorescence of the placoid lesions in the early phase and hyperfluorescence in the late phase. Indocyanine green angiography showed hypofluorescence during all phases. These findings imply an occlusion of the choriocapillaris. Fluorescein angiography also showed occlusion of the peripheral retinal vessels. With systemic corticosteroids and prostaglandin I2 derivative, the fundi recovered almost completely to normal 3 months later.

Adult↗

PubMedDate not supplied

Retinal cell death by light damage.

PURPOSE: To determine the relationship between apoptotic photoreceptor cell death and the duration of light exposure. METHODS: Ten-week-old male albino rats (Wistar strain) were dark-adapted for 2 days and then exposed to intense light for 12 hours, and 1, 2, 3, 7, 14, 21, and 28 days. The presence of apoptosis was confirmed by electron microscopy and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) method. Differences in the apoptotic processes of the photoreceptor cells in the superior, posterior pole, and inferior portions of the retina were determined. RESULTS: Photoreceptor cells showed TUNEL-positive staining, whereas the cells in the inner nuclear layer, ganglion cell layer and retinal pigment epithelia exhibited weak positive or negative TUNEL staining. By electron microscopy, photoreceptor cells showed typical apoptotic nuclear changes and formation of apoptotic bodies. CONCLUSIONS: The sensitivity to light damage and style of death differed among retinal cells by location and cell type.

Animals↗