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Biomedical subjects

R Y Foos

Publications and source records attributed to R Y Foos.

At least 19 recordsLinked to original sources
PubMed1992

Mycobacterium fortuitum keratitis. Clinicopathologic correlates and corticosteroid effects in an animal model.

Mycobacterium fortuitum keratitis is an indolent infection of traumatized corneas in humans. To study this disorder in an animal model, 10(4) M fortuitum organisms (10 microliters) were inoculated into the stroma of both corneas of 16 New Zealand albino rabbits. Eight of the rabbits were also given bilateral subconjunctival injections of methylprednisolone acetate (20 mg in 0.5 ml) at the time of inoculation. Two corticosteroid-treated and two untreated rabbits were selected each week after inoculation for histopathological examination and quantitative cultures. Corneal lesions in corticosteroid-treated eyes were characterized clinically by indolent ulcerations and satellite lesions that slowly enlarged; on histopathologic examination at each week, acute inflammation and microorganisms were consistently present. Corneal lesions in untreated eyes were characterized clinically by small infiltrates that progressed little over time; at weeks 1 and 2, light microscopic examination showed intrastromal granulomatous and/or mixed acute and chronic inflammation with focal intrastromal necrosis, but at weeks 3 and 4 there was no evidence of active disease. Organisms could not be identified microscopically in corneas of any untreated rabbits. Mean values for quantitative cultures of corneas were higher in corticosteroid-treated rabbits after week 1, although standard deviations were large. These results suggest that M fortuitum keratitis in rabbits is made worse by corticosteroid use. Clinical and histopathologic changes were compared with human disease and found to be similar in corticosteroid-treated rabbits.

Animals↗
PubMed1991

Ultrastructural and immunohistochemical features of coronal adenomas.

We studied by electron microscopy three coronal adenomas discovered incidentally in eyes removed surgically. Tumor cells displayed prominent intercellular interdigitations with numerous desmosomes, mitochondria, abundant rough endoplasmic reticulum, and nuclei with membrane infoldings and a granular chromatin pattern. In these characteristics, the tumor cells were identical to nonpigmented ciliary epithelium of the ciliary processes. These growths contained abundant extracellular material, which showed a dimorphic pattern of complex reduplicated basal lamina and granular areas without structure. Immunohistochemical studies on formalin-fixed, paraffin-embedded coronal adenomas demonstrated type IV collagen and laminin in the extracellular material. These findings confirm that coronal adenomas develop from nonpigmented ciliary epithelium and that the extracellular material of these tumors contains components normally present in basement membranes.

Adenoma↗
PubMed1991

Immunopathologic features of retinal lesions in multiple sclerosis.

To further characterize the nature of retinal periphlebitis and retinitis in multiple sclerosis, immunoperoxidase studies were performed on retinal tissue from multiple sclerosis patients at autopsy. Antibodies against myelin basic protein stained the optic nerve but not the retina. Both normal and multiple sclerosis retinas showed staining of Müller cells with Leu-7 (a monoclonal antibody that cross-reacts with myelin associated glycoprotein and natural killer cells). Nerve fiber bundles of the optic nerve in cases with multiple sclerosis and controls also showed staining with Leu-7 antibody. Tissue-bound IgG was demonstrated on retinal ganglion cells in six of seven multiple sclerosis cases but not in controls.

Antibodies, Monoclonal↗
PubMed1990

HMB-45 antibody reactivity in pigmented lesions of the conjunctiva.

Conjunctival pigmented lesions, including ten compound nevi, three subepithelial nevi, two acquired melanoses, and six melanomas, were examined histologically and immunohistochemically to determine the specificity of mouse monoclonal HMB-45 antibody for these lesions. Eleven of 13 nevi, two of two acquired melanoses, and six of six melanomas stained with this antibody. Conjunctival melanomas showed intense and diffuse cytoplasmic staining; compound nevi and subepithelial nevi showed less intense but diffuse reaction. There was strong staining in melanocytic cells at the junction of the epithelium and substantia propria in compound nevi and acquired melanoses. Unlike skin nevi, conjunctival nevi show HMB-45 reactivity in their stromal components. Immunoreactivity to HMB-45 does not distinguish benign from atypical or malignant melanocytic lesions of the conjunctiva.

Adolescent↗
PubMed1990

Traumatic neuroma of the eyelid associated with ptosis.

A 17-year-old boy presented with persistent swelling and ptosis of the eyelid after blunt injury. Histologic examination revealed a clinically unsuspected traumatic neuroma. Ptosis and the traumatic neuroma persisted despite two eyelid operations. Traumatic neuroma is rare after blunt trauma; it has not been previously reported in the eyelid. It is important to identify this lesion because complete excision may help to prevent recurrence.

Adolescent↗
PubMed1990

Necrotizing retinopathy after intraocular inoculation of murine cytomegalovirus in immunosuppressed adult mice.

A light microscopic study was done to investigate retinal changes in healthy and immunosuppressed mice after intraocular inoculation of murine cytomegalovirus (MCMV). A 0.01-ml inoculum containing 10(5) plaque-forming units of MCMV was placed behind the lens in 138 4-week-old Swiss Webster mice. Ninety-eight mice were immunosuppressed with 0.2 mg/g of cyclophosphamide given intraperitoneally at the time of inoculation and 0.1 mg/g of cyclophosphamide every 5 days thereafter. Selected eyes were examined on postinoculation days 5, 10, 15, and 16-20. Evidence of viral infection was most prominent in uveal tissue. Uveal infection developed whether or not animals received cyclophosphamide, but retinal necrosis developed only in immunosuppressed mice. Focal retinal necrosis, primarily involving the outer retinal layers and retinal pigment epithelium, was first observed in an eye examined on day 10. Retinopathy from MCMV was present in three of five eyes (60%) examined on day 15, and in six of 16 eyes (37.5%) examined between days 16-20. Retinal disease was characterized by full-thickness retinal necrosis, scattered cytomegalic cells, intranuclear and intracytoplasmic viral inclusions, and acute and chronic inflammation. These results indicate that MCMV can produce a necrotizing retinopathy in mice and that immunosuppression facilitates infection. Although ocular MCMV infection in immunosuppressed adult mice is a potential model for study of human CMV retinopathy, many differences exist between human CMV and MCMV and between the ocular diseases they produce.

Animals↗
PubMed1990

Infectious crystalline keratopathy in a neonatal infant.

Bilateral white crystalline opacities of the central corneas were found at autopsy in the eyes of a 17-day-old girl with Turner's Syndrome. Corticosteroid therapy had not been used. Histopathologic and electron microscopic evaluation revealed clusters of gram-negative rods between relatively intact stromal lamellae. Inflammation was mild and restricted to the limbus and peripheral cornea. This case represents an unusual presentation of an infectious crystalline keratopathy.

Corneal Diseases↗
PubMed1989

Dual infection of retina with human immunodeficiency virus type 1 and cytomegalovirus.

We examined retinal tissue from eight human immunodeficiency virus type 1 (HIV-1) seropositive patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex for evidence of dual infection with HIV-1 and cytomegalovirus. Culture demonstrated simultaneous infection with HIV-1 and cytomegalovirus in two of 13 retinal specimens. This was confirmed by both immunofluorescence and immunohistochemical staining. Moreover, coinfection of individual cells with cytomegalovirus and HIV-1 was observed by immunohistochemical staining. Infection of retina with cytomegalovirus or HIV-1 alone occurred in one and six of the 13 retinal specimens, respectively. HIV-1 antigens were present on scattered cells in all layers of the retina and on retinal vascular endothelium. HIV-1 was isolated from retinal tissue derived from eyes both with and without gross ocular lesions. Cytomegalovirus antigens were found in all layers of the retina, but not on vascular endothelial cells. The atypically rapid clinical progression of retinitis in one of the patients with dual HIV-1 and cytomegalovirus infection suggests the possibility that interactions between these two viruses may influence retinal disease in patients with AIDS.

AIDS-Related Complex↗
PubMed1989

Keratinizing corneal intraepithelial neoplasia.

Corneal intraepithelial neoplasia (CIN) is the term applied by some authors to the spectrum of disease ranging from mild dysplasia to carcinoma in situ. Such lesions usually are associated with dysplastic or neoplastic processes at the limbus or adjacent conjunctiva; isolated corneal dysplasia is rare. Clinically, CIN appears as a geographic, gray, translucent thickening of the epithelium with fimbriated or scalloped borders and lesions often contain scattered white dots. We report a case of intraepithelial neoplasia limited to the cornea that had the unusual clinical appearance of a white plaque, which prompted the misdiagnosis of a calcific scar. Histopathologic examination of the debrided tissue revealed intraepithelial neoplasia and marked hyperkeratosis as the cause of the opacification.

Corneal Diseases↗
PubMed1988

Traumatic dehiscence of incisions seven years after radial keratotomy.

We studied the clinical and pathologic features of a traumatically ruptured eye seven years after radial keratotomy. The radial keratotomy incisions were identified and topographically related to perforation sites. Three radial keratotomy incisions were perforated. Seven additional incisions were partially separated. Radial keratotomy incision depths ranged from 50% to 90% in the remaining incisions. All incisions showed disruption of Bowman's membrane, 15 of 16 showed malapposition of Bowman's membrane, and 14 of 16 showed epithelial plugging. In this case the healing and strength of radial keratotomy incisions were suboptimal seven years after the procedure.

Eye Injuries↗
PubMed1988

Mycobacterium fortuitum keratitis.

Two of four cases of Mycobacterium fortuitum keratitis occurred after corneal surgery with contact lens wear, one was associated with extended contact lens wear alone, and one occurred after a foreign body injury. All cases were characterized by pain, conjunctival hyperemia, stromal inflammation, and ulceration. Diagnosis was made by culture and acid-fast staining of corneal scrapings. On the basis of published experience with amikacin for the treatment of nonocular M. fortuitum infections, three patients were treated with topical amikacin. Two patients responded clinically, but histopathologic examination of a penetrating keratoplasty specimen in one of the two disclosed persistent infection. One patient was cured of early disease by debridement alone. Rapid diagnosis and absence of corticosteroid use were the two most important determinants of successful therapy. In advanced cases, infection may be cured and useful vision restored by penetrating keratoplasty.

Adult↗
PubMed1988

Quantitation of tumor seeding from fine needle aspiration of ocular melanomas.

Twenty-two fine needle (30 gauge) aspirations were performed in eyes enucleated for the clinical diagnosis of melanoma. Cytologic preparations were evaluated for adequacy of material, and needle tracts were evaluated for tumor implantation. A scleral marking method was used to identify all needle tracts. The number of tumor cells in tracts of direct transscleral aspirates was compared to those in tracts of indirect aspirates that traversed the anterior chamber or vitreous. Cellular material obtained with 30-gauge needles was sufficient for the diagnosis of malignant melanoma in all but one case. While 14 of 21 (67%) of all fine needle aspiration tracts and eight of 15 (53%) of indirect tracts contained tumor cells, the number of tumor cells was less than that associated with tumor growth in experimental models. Indirect aspirate tracts contained significantly fewer cells than tracts of direct aspirates (P less than .001).

Biopsy, Needle↗