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Biomedical subjects

D M Albert

Publications and source records attributed to D M Albert.

At least 181 records · Page 10Linked to original sources

Comparison of transillumination and histologic slide measurements of tumor diameter in uveal melanoma.

Tumor size is an important prognostic factor for deaths due to uveal melanoma. The objectives of this study are: (1) to determine the association between largest tumor diameter assessed by clinical transillumination and largest tumor diameter assessed by measurement of the histologic slide; (2) to predict a clinical transillumination diameter for each enucleation specimen based on the best combination of histologic variables--diameter, height, location, and tumor shape; and (3) to use the predicted transillumination diameter in place of histologic diameter measurement as a prognostic factor for patients treated by enucleation in order to reevaluate previously reported survival outcomes for patients treated by proton beam and enucleation. Comparison of measurements on 40 eyes indicated that transillumination largest diameter measurements were larger than histologic slide measurements (mean difference, 2.87 mm). Multiple linear regression analysis yielded the following equation: transillumination diameter = [4.73 + (0.58 X histologic diameter) + (0.38 X histologic height) + (1.87 X anterior location)]. Using the actual and predicted transillumination measurements, the results of this study support a previously published report on these data: treatment type, tumor size, and location were predictive of melanoma-related deaths, metastases, and all deaths.

Evaluation Studies as Topic↗

Anterior proliferative vitreoretinopathy. Clinicopathologic, light microscopic, and ultrastructural findings.

Proliferative vitreoretinopathy (PVR) involving the posterior and equatorial retina is an established clinicopathologic entity. Clinically, a similar process, anterior PVR (APVR), results in anterior dragging of the peripheral retina by membranes which connect to the ciliary body or iris and cause circumferentially and radially fixed retinal folds. The pathology of APVR, however, has not been reported. The authors describe pathologic findings in 28 cases of APVR and ultrastructural pathologic findings in 6 surgical APVR specimens. Anterior PVR was frequently associated with retinal detachment (RD) repair (96%) and trauma (38%). Residual vitreous at the vitreous base virtually always provided a scaffold for membranes containing proliferating cells and deposited extracellular matrix. Major components of APVR membranes were fibrovascular tissue (71%), pigment epithelial cells (43%), fibrous and corneal stromal ingrowth (32%), and glial proliferation (18%). Because of its anterior location, APVR membranes also incorporated ciliary epithelium and corneal endothelium. Contraction of APVR membranes caused anterior retinal displacement and detachment in anatomic configurations corresponding to narrow and wide peripheral troughs. The authors' findings indicate that APVR is a distinctive clinicopathologic entity which may complicate rhegmatogenous RD and its repair.

Adult↗

Preliminary results on phosphorus-31 nuclear magnetic resonance evaluation of human uveal melanoma in enucleated eyes.

Clinical evaluation of uveal melanomas by nuclear magnetic resonance (NMR) techniques depends on ascertaining how these tumors characteristically appear in NMR images and spectra. The authors have determined NMR characteristics of suspected uveal melanomas by phosphorus-31 (31P) NMR spectroscopy of freshly enucleated human eyes. Nuclear magnetic resonance examination was performed at 8.45 Tesla within 90 minutes after enucleation. Enucleated eyes were maintained at 4 degrees C in tissue culture medium during the 30 minutes required for transport. Nuclear magnetic resonance spectra were obtained within 10 minutes, a clinically acceptable time, using a two-turn 31P surface coil. Spectral parameters included 10-kHz spectral width, 1024 data points, and 0.5-second recycle delay. Phosphorus-31 NMR spectroscopy allowed differentiation of choroidal melanomas from normal ocular structures. Differentiating features include significant peaks in tumor spectra due to the phosphodiesters glycerol 3-phosphoryl ethanolamine (GPE) and glycerol 3-phosphorylcholine (GPC), and the phosphomonoesters phosphorylethanolamine (PE) and phosphorylcholine (PC). These preliminary data are encouraging and suggest that clinical trials at the lower magnetic field strengths available in NMR imaging systems seem feasible and warrant investigation.

Choroid Neoplasms↗

Paraproteinemic crystalline keratopathy.

Paraproteinemic crystalline keratopathy is an uncommon complication of multiple myeloma and other plasma cell dyscrasias. A case of 16 years' duration was associated with an IgG kappa monoclonal gammopathy and recurrent uveitis. The corneal changes were unusually extensive and distributed throughout all corneal layers. The deposits consisted of diffuse, small, polymorphic aggregates, which were iridescent in the superficial cornea, mat elsewhere, and associated with a diffuse stromal haze; specular microscopy showed additional features. Both corneas were thickened. The deposits failed to stain histochemically, except patchily with Masson Trichrome. There was extensive immunohistochemical labeling for IgG, kappa, and surprisingly, lambda. Ultrastructurally, pleomorphic deposits were found in every corneal cell; paracrystalline deposits with internal banding were seen only in the basal epithelium. Keratocytes and endothelial cells were damaged and reduced in number. Disease recurred in a corneal graft. Three main types of paraproteinemic keratopathy can be distinguished. The deposits probably represent various metabolic products of the monoclonal protein. This is not necessarily a benign condition; hematologic control may be necessary on purely ophthalmological criteria.

Corneal Opacity↗

Idiopathic retinal gliosis mimicking a choroidal melanoma.

A 37-year-old woman has followed for more than 10 years with an amelanotic peripheral intraocular tumor. This solitary lesion grew slowly and, because of the possibility of an amelanotic melanoma, the eye was enucleated. Histopathology revealed a localized "massive" retinal gliosis (MRG). Immunohistochemical staining for S-100 protein and glial fibrillary acidic protein (GFAP) were positive. Electron microscopy showed a highly fibrillar component and basement membrane formation in the extracellular space. Proliferating cells contained abundant fine filaments. These findings confirmed the glial origin of the proliferating cells. The previously undefined relationship of these localized forms of MRG with solitary astrocytomas is discussed.

Adult↗

Idiopathic bilateral lipid keratopathy.

A 52-year-old Mexican man presented with asymptomatic, bilaterally symmetrical lipid infiltrates of the cornea and adjacent limbus. No evidence of previous ocular disease or systemic disorder of lipid metabolism could be detected. Penetrating keratoplasty of the right eye was required. The cornea was rigid and thick, with posterior bulging into the anterior chamber. Light microscopy revealed deep corneal lipid granules, foamy histiocytes, vascularisation, and chronic non-granulomatous inflammation. Transmission electron microscopy showed extracellular lipid spaces and numerous intracytoplasmic lipid vacuoles in histiocytes, keratocytes, conjunctival epithelium, and the endothelium of blood vessels in the corneal stroma and adjacent limbal conjunctiva. Histochemical analysis revealed the presence of neutral fats, free fatty acids, cholesterol, and phospholipids.

Cholesterol↗

Sudden visual loss associated with clostridial bacteraemia.

A patient with endogenously acquired Clostridium septicum panophthalmitis is presented. The patient exhibited a striking sequence of signs and symptoms associated with this devastating ocular infection. Intensive antibiotic therapy was ineffective and enucleation of the globe was required. The microscopic pathology of the enucleated globe showed extensive infarction and necrosis of ocular structures in association with the panophthalmitis. In addition thrombosis of the central retinal artery and of choroidal vessels was observed.

Aged↗

The usefulness of routine alcian blue staining of corneal specimens.

To determine the diagnostic usefulness of routine staining of corneal buttons with alcian blue, we evaluated 150 consecutive corneal specimens with hematoxylin and eosin and alcian blue stains. Overall, 67% of specimens demonstrated deposition of acid mucopolysaccharide. More specifically, positive alcian blue staining was observed in 88% of specimens with pannus, 83% of specimens with stromal downgrowth, 71% of specimens with stromal scarring, and 67% of specimens with interstitial keratitis. In 80% of these cases, the positive alcian blue stain correlated to pathology noted on hematoxylin and eosin sections. In 20% of cases, we could not explain the reason for the presence of alcian blue staining. Except for macular dystrophy of the cornea, the presence, strength, and location of staining did not provide useful information in terms of making a specific clinical diagnosis. Consequently, alcian blue should be used only in those settings in which the pathologist needs to document or confirm the abnormal presence or absence of acid mucopolysaccharide deposition.

Alcian Blue↗

Expression of intermediate filaments and synaptophysin show neuronal properties and lack of glial characteristics in Y79 retinoblastoma cells.

The expression of intermediate filaments and synaptophysin in Y79 retinoblastoma cells was studied. The cells grew normally in suspension as floating aggregates. Sodium butyrate and dibutyryl cyclic AMP induced adherence and rapid spreading of Y79 cells on laminin-coated substratum and many of the cells presented long cellular extensions. As judged by immunostaining with monoclonal and polyclonal antibodies, most untreated Y79 cells expressed synaptophysin, whereas only vimentin intermediate filaments were detected in a few cells. A more bright fibrillar vimentin-positivity, which responded by coiling to disruption of microtubules, could be seen in the spread cells. Furthermore, especially when exposed to butyrate, a distinct fibrillar positivity could be revealed in some of the spread cells with antibodies recognizing a phosphorylated epitope in neurofilaments. Western blotting results showed the presence of the molecular weight 57,000 vimentin polypeptide and the molecular weight 38,000 synaptophysin polypeptide in both undifferentiated and spread Y79 cells, and a phosphorylated molecular weight 200,000 neurofilament polypeptide in spread cells only. In contrast, both immunostaining and Western blotting results with several antibodies indicated lack of glial fibrillary acidic protein in Y79 cells suggesting hence, a lack of glial differentiation. The present results do not support the hypothesis that retinoblastomas would originate from a common precursor cell of neurons and glia, and show the presence of mainly neuronal features in Y79 retinoblastoma cells.

Blotting, Western↗

Pseudomonas corneoscleritis.

We evaluated three cases of Pseudomonas aeruginosa corneoscleritis, one associated with the use of contaminated eyedrops; another in an elderly, debilitated patient; and the third in a patient who had previously undergone penetrating keratoplasty. In the first two cases, control of the infection was achieved by intensive antibiotic therapy alone. The third case required evisceration of the eye following spontaneous perforation at the site of scleral involvement. Histopathologic findings showed persistence of the organism in the sclera despite intensive antibiotic therapy for six days.

Aged↗

Death from uveal melanoma. Number of epithelioid cells and inverse SD of nucleolar area as prognostic factors.

Criteria for the Callender classification of uveal melanoma are subjective and lead to variations among observers of the same tumor. Two other measures for cell type-the number of epithelioid cells per high-power field (Epi/HPF) and the inverse SD of nucleolar area (ISDNA)-were evaluated as prognostic factors for survival following enucleation for uveal melanoma in 232 patients. Variables significantly related to the number of Epi/HPF were related to ISDNA. Larger, more anteriorly located tumors had a high number of Epi/HPF and a low ISDNA. The two measures were also correlated. Using Kaplan-Meier survival analysis, both measures were related to tumor deaths. Worse prognosis was associated with a higher number of Epi/HPF and a lower ISDNA. Considered together in Cox' proportional hazards analysis, both measures independently predicted outcome. Separately, each measure predicted uveal melanoma-related deaths, in combination with largest tumor dimension, invasion of tumor to the line of transection, and location of the anterior tumor margin. Although ISDNA is the more objective measure of cell type, its practicality compared with other measures of cell type must also be considered.

Adult↗

Proton and sodium 23 magnetic resonance imaging of human ocular tissues. A model study.

Clinical evaluation of uveal melanomas by magnetic resonance imaging (MRI) techniques depends on developing an understanding of the appearance of these tumors in magnetic resonance (MR) images. We have determined MR characteristics of uveal melanomas by proton (1H) and sodium 23 MRI of freshly enucleated human eyes at 1.5 tesla. The MR images were obtained using two-turn proton and 23Na surface coils, designed to both transmit and receive the radiofrequency signal. Proton MRI techniques included saturation recovery and spin echo; the gradient-recalled echo technique was used for 23Na MRI. Proton and 23Na MR images provide complementary information; contrast between intraocular tumors and vitreous, lens, or subretinal hemorrhage may be varied by using MR pulse sequences that emphasize tissues based on T1, T2, proton, or sodium density values. A combination of proton and 23Na MRI provides differentiation between normal ocular structures and intraocular tumors, as well as associated complications, such as retinal detachments and subretinal hemorrhages.

Eye↗

Olfactory neuroblastoma metastatic to the eye.

A case of olfactory neuroblastoma metastatic to the choroid is reported and described. Histologically, the tumor consisted of islands of small round cells, many of them surrounding blood vessels in a 'pseudorosette' pattern. Numerous mitotic figures were present. Transmission electron microscopy reveals neuritic processes containing neurosecretory granules and microtubules, features characteristic of olfactory neuroblastoma. This is the first published case of an olfactory neuroblastoma demonstrating intraocular metastasis.

Choroid Neoplasms↗

Historic review of retinoblastoma.

Retinoblastoma was first described as a specific entity by James Wardrop in 1809, with enucleation as his suggested treatment. Histologic studies including those of Flexner and Verhoeff and subsequent electron microscopy have given insights into its pathogenesis. The establishment of cell lines of retinoblastoma, the "nude" mouse model, and other animal models have contributed additional information. Classic genetic and epidemiologic studies have led to a broad and intense interest in the tumor despite its relative infrequency. Attempts now in progress to identify and characterize the oncogene for retinoblastoma may prove to be the most exciting part of the history of retinoblastoma.

Eye Neoplasms↗