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Biomedical subjects

R L Font

Publications and source records attributed to R L Font.

At least 91 records · Page 5Linked to original sources
PubMed1991

HSV antigens and HSV DNA in avascular and vascularized lesions of human herpes simplex keratitis.

Fifty-one corneal buttons obtained by penetrating keratoplasty from patients with a preoperative clinical diagnosis of nonulcerative herpetic keratitis and/or disciform stromal scarring (44) as well as ulcerative necrotizing stromal keratitis (7) were processed for herpes simplex virus (HSV) antigens using an immunoperoxidase technique and for HSV DNA by the polymerase chain reaction (PCR). HSV antigens were detected significantly more often (p less than 0.025) in specimens with avascular nonulcerative keratitis than in those with vascularization. In contrast to HSV antigens, HSV DNA was identified at equal proportions in avascular and vascularized lesions. Both HSV antigens and HSV DNA were detected in all specimens from patients with ulcerative necrotizing stromal keratitis. The implications of these findings with regard to possible mechanisms underlying herpetic keratitis in man are discussed.

Adolescent↗
PubMed1990

Unusual mucopolysaccharide disorder with corneal and scleral involvement.

A 68-year-old man and a 66-year-old woman had diffuse corneal stromal deposits that stained with alcian blue and colloidal iron but did not react with periodic acid-Schiff stain and lipid stains. Similar deposits were found within postmortem sclera in one case, but not in other ocular or extraocular tissues. The abnormal material was sensitive to testicular hyaluronidase and chondroitinase. The material reacted with monoclonal antibody 9-A-2 after digestion by chondroitinase AC in one case and ABC in both cases, which is consistent with the identification of the glycosaminoglycans chondroitin 4-sulfate and dermatan sulfate. Electron microscopic examination of the cornea in both cases disclosed granular material in vacuoles dispersed extracellularly and, rarely, in keratocytes. Results of blood and skin fibroblast enzyme assays for clinically relevant mucopolysaccharidoses and mucolipidoses were normal in both patients, and there were no somatic abnormalities suggesting a storage disease.

Aged↗
PubMed1990

Granulomatous acne rosacea of the eyelids.

We describe the clinicopathologic features of the papular form of granulomatous acne rosacea of the eyelids. This unusual cutaneous disorder is typified by painless eruptions of reddish to yellowish brown, occasionally ulcerative papules symmetrically distributed around the eyelids, lower part of the forehead, nasolabial folds, and upper lip. Histopathologically, the lesions display caseating and noncaseating dermal granulomas that mimic those seen in tuberculosis, tuberculoid leprosy, sarcoidosis, and other diseases. The disorder responds well to systemic tetracycline therapy but may involute spontaneously during a period of months to years. The distinction of this disorder from other dermal granulomatous diseases, such as tuberculosis, leprosy, syphilis, and foreign bodies, is important because of the different therapeutic implications.

Aged↗
PubMed1990

Lymphomatoid granulomatosis of eyelid and brow with progression to lymphoma.

Lymphomatoid granulomatosis is an uncommon lymphoreticular disease that primarily involves the lungs, skin, and central nervous system and has a high mortality rate. This is the first report in the American literature of lymphomatoid granulomatosis with involvement of the skin of the eyelid and brow. After a protracted clinical course, the patient died of pulmonary complications.

Eyebrows↗
PubMed1990

Bilateral keloid-like myofibroblastic proliferations of the cornea in children.

Two 6-month-old white boys developed localized multifocal white nodules of the anterior corneal stroma without evidence of antecedent trauma, inflammatory disease, or familial occurrence. The first patient had bilateral lesions initially; the second patient initially had unilateral involvement followed by a corneal nodule in the second eye at 11 years of age. Light and electron microscopic studies of the lesions in both patients were similar and disclosed stromal nodules composed of proliferating myofibroblasts, activated fibroblasts, and haphazardly arranged fascicles of collagen. Immunohistochemical studies revealed that the spindle cells within the nodules expressed immunoreactivity for vimentin and alpha-smooth muscle actin. Management options for these slowly progressive corneal lesions include lamellar versus penetrating keratoplasty and topical corticosteroids.

Child, Preschool↗
PubMed1990

Herpes simplex stromal and endothelial keratitis. Granulomatous cell reactions at the level of Descemet's membrane, the stroma, and Bowman's layer.

Fifty-three (25%) of 215 keratectomy specimens of patients with herpes simplex stromal keratitis displayed granulomatous reactions at the level of Descemet's membrane (50/53), midstroma (13/53), and Bowman's layer (5/53). Using an immunoperoxidase technique, herpes simplex virus (HSV) antigens were detected in keratocytes, endothelial cells, and foci of epithelioid histiocytes and multinucleated giant cells around Descemet's membrane. Both granulomatous reactions and HSV antigens were identified significantly more often in specimens with ulcerative necrotizing stromal keratitis than in those from patients with stromal scarring or nonulcerative nonnecrotizing keratitis (P less than 0.00001 and P less than 0.005, respectively). Herpes simplex virus antigens also were present in endothelial cells adjacent to foci of granulomatous reactions around Descemet's membrane in association with disciform stromal scarring. To our knowledge, this is the first demonstration of HSV antigens in human corneal endothelial cells and in the granulomatous reactions at the level of Descemet's membrane.

Adolescent↗
PubMed1990

A clinicopathologic study of three carcinoid tumors metastatic to the orbit. Immunohistochemical, ultrastructural, and DNA flow cytometric studies.

Three patients with histopathologically proven orbital metastatic lesions from a carcinoid tumor are reported. Computed tomography (CT) disclosed a well-circumscribed orbital mass in two of three cases. Each tumor was studied by both light and electron microscopy as well as immunohistochemistry and DNA flow cytometry. A review of the literature discloses the relatively rare occurrence of carcinoid tumors metastasizing to the eye and orbit. With the exception of one case, the reported metastatic carcinoid tumors to the uvea all developed from primary bronchial carcinoids. In contrast, the vast majority of the reported orbital metastases arose from ileal carcinoids. Immunohistochemical markers such as chromogranin A, synaptophysin, and serotonin have proven to be useful diagnostic tools in evaluating carcinoid tumors. Furthermore, DNA flow cytometry may be of prognostic value in patients with metastatic carcinoid tumor.

Adult↗
PubMed1990

The diagnostic utility of desmin. A study of 584 cases and review of the literature.

The diagnostic utility of several antibodies against desmin and their optimal staining conditions have not been systematically evaluated. Sections of paraffin-embedded tissues from 584 cases were stained with a monoclonal antibody against desmin (Clone DER 11 from DAKO), using an avidin-biotin-peroxidase technique. The results were tabulated and compared with those from previous reports. The following observations were made: (1) When pronase digestion was performed before staining, desmin was equally demonstrable in tissues fixed in formalin, Zenker's, Bouin's, or B5 fixative; however, desmin staining was lost or significantly diminished in tissues fixed in absolute ethyl alcohol. In contrast, when pronase was not used, a positive staining was demonstrated only in tissue fixed in absolute ethyl alcohol. (2) Positive staining was found in normal muscle (92 of 92 cases), leiomyoma (12 of 13), rhabdomyoma (6 of 6), rhabdomyosarcoma (31 of 31), leiomyosarcoma (18 of 26). (3) Desmin was never found in epithelia, normal mesenchymal tissue other than muscle, tumors stimulating rhabdomyosarcoma, and epithelial tumors. (4) A positive staining was documented in 1 tumor (a fibrous histiocytoma) of 42 benign predominantly spindle cell tumors and in 8 of 89 predominantly spindle cell sarcomas. (5) Desmin was never documented in myoepithelial cells but stained myofibroblasts in 2 of 12 examples of granulation tissue and in 29 of 67 samples containing tumor-associated desmoplasia. The authors' data on the diagnostic sensitivity and specificity of the evaluated antibody should improve the use of desmin in diagnostic pathology.

Antibodies, Monoclonal↗
PubMed1990

Isolation of a microsporidian from a human patient.

Several genera of microsporidia have been identified morphologically in human tissue but none has yet been propagated in vitro. These primitive, obligate intracellular parasitic protozoa are poorly understood pathogens of a wide variety of vertebrates and invertebrates. In humans they are especially important as opportunistic pathogens in AIDS patients. A microsporidian was recovered from a human patient and propagated in vitro. The organism has diplokarya, divides by binary fission, and often is found free in the host cell cytoplasm. The name Nosema corneum is suggested.

Animals↗
PubMed1990

Expression of the functional cone phototransduction cascade in retinoblastoma.

Retinoblastoma is a malignant intraocular tumor that primarily affects small children. These tumors are primitive neuroectodermal malignancies, however some of them show morphologic evidence of differentiation into photoreceptors. Phototransduction cascades are a series of biochemical reactions that convert a photon of light into a neural impulse in rods and cones. The components of these cascades are uniquely expressed in photoreceptors and, although functionally similar, distinct components of these cascades are expressed in rods and cones. Using HPLC anion exchange chromatography, Western blot analysis, and specific monoclonal and polyclonal antibodies, we found that the cone but not the rod cGMP phosphodiesterase is functionally expressed in all six primary retinoblastomas examined and in three continuous retinoblastoma cell lines. Morphologic evidence of differentiation did not correlate with the expression of the enzyme. Furthermore, GTP analogues could activate the phosphodiesterase activity suggesting that an intact phototransduction cascade is present in the tumors. The presence of the cone phototransduction cascade in retinoblastoma confirms that this tumor has biochemically differentiated along the cone cell lineage.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1990

Corneal myxoma. Case report and review of the literature.

Myxoma of the cornea is extremely rare. To our knowledge, only two cases have been reported in the literature. We report an additional case of a corneal myxomatous lesion that presented as a subepithelial, gelatinous, and whitish mass. Histologic examination revealed a loose mucoid stroma, rich in hyaluronic acid, with a relative paucity of cells.

Adult↗
PubMed1990

Corneal microsporidiosis. A case report including ultrastructural observations.

Stromal keratitis and iritis developed in the left eye of a healthy 45-year-old man with no history of ocular disease, trauma, or contact lens wear. The clinical course over a 2-year period was characterized by progressive central disciform keratitis, recurrent anterior stromal patchy infiltration, and iritis which was partially controlled with topical corticosteroids and broad-spectrum antibiotics. Results of bacterial, viral, fungal, and chlamydial cultures were negative. Results of histopathologic examination of a corneal biopsy specimen and, later, a penetrating keratoplasty specimen showed many extracellular and intracellular spores in degenerating keratocytes. By electron microscopy there were encapsulated oval structures measuring approximately 3.5 to 4 microns in length x 1.5 microns in width. Mature spores had well-developed cell walls that contained two abutted nuclei (diplokaryon) and a redundant polar tubule with six coils. These structures are characteristic of a protozoa in the genus Nosema.

Animals↗
PubMed1989

Neuroglial choristoma presenting as congenital lid tumor.

A 12-month-old boy presented with a diffuse solid tumor of the nasal portions of the lower lid, which had caused almost complete narrowing of the interpalpebral fissure since birth. Clinically, it was suspected to be a mesenchymal tumor. Radiological studies revealed no bony defects in the orbit. The computerized tomographic (CT) scan disclosed a porencephalic cyst in the ipsilateral cerebral hemisphere. Excisional biopsy of the lid tumor revealed ectopic neuroglial tissue. The immunocytochemical demonstration of glial fibrillary acidic protein (GFAP) was consistent with the electron microscopic findings that disclosed fibrillary astrocytes with an abundance of typical 9- to 10-nm glial filaments. Heterotopic neuroglial tissue should be part of the differential diagnosis of congenital lid tumors; its occurrence may be associated with other anomalies of cerebral organogenesis.

Biopsy↗
PubMed1989

Polychromatic corneal and conjunctival crystals secondary to clofazimine therapy in a leper.

A 67-year-old man had a diagnosis of dapsone-resistant lepromatous leprosy. He received clofazimine (Lamprene) at a dosage of 100 mg twice daily. After 3 years of therapy, results of slit-lamp examination disclosed myriad polychromatic crystals diffusely involving the cornea and perilimbal conjunctiva of both eyes. Thick sections (1 micron) from a conjunctival biopsy showed numerous rectangular-to-rhomboidal crystals within stromal fibroblasts and macrophages. By electron microscopy, these cells contained elongated, membrane-bound, cleft-like spaces that corresponded to the sites where crystals had been present previously. Additionally, complex lipid inclusions were observed in mesenchymal cells as well as in endothelial cells and pericytes of blood vessels. The ocular side effects of clofazimine therapy are reviewed. Clofazimine-induced keratopathy should be included in the differential diagnosis of patients with polychromatic crystalline deposits in the corneas. To the best of the authors' knowledge, this complication of clofazimine therapy has not been described previously.

Aged↗